General Report

Transcription

General Report

Halcrow Yolles
Queen’s Quay Terminal 207 Queen’s Quay West
Suite 550 PO Box 132 Toronto Ontario M5J 1A7
tel +1 416 363 8123 fax +1 416 363 0341
halcrowyolles.com
Ms. Connie Durante, Parish Manager
St. Bonaventure’s Church
1300 Leslie Street
Toronto, Ontario
M3C 2K9
November 6, 2007
Dear Ms. Durante:
Re:
Roof Condition Assessment and Sustainable Strategies
Our Project No. T070612
As requested, in accordance with our proposal dated May 30, 2007, Halcrow Yolles performed a condition
assessment of the roofs for the buildings located at 1300 Leslie Street, Toronto, Ontario.
Enclosed please find a copy of the report. Once you have had an opportunity to review the report, we would
be pleased to schedule a meeting at your convenience to discuss the findings. To facilitate referencing of the
various roofs, we have labelled them alphabetically. We recommend reviewing the report in conjunction
with the attached Roof Key Plan to accurately identify the roofs discussed.
Should you have any questions or concerns, please do not hesitate to contact the undersigned.
Yours sincerely,
Halcrow Yolles
Per:
Steven Gray, B.A.Sc., M.Eng.
steven.gray@halcrowyolles.com
Direct dial +1 416 363 8134 ext: 1531
Per:
Anne Floros, M.Eng., P.Eng.
Project Engineer
anne.floros@halcrowyolles.com
Direct dial +1 416 363 8134 ext: 1403
Roof Condition
Assessment and
Sustainable Strategies
St. Bonaventure’s
Church
Toronto, Ontario
Prepared For:
Ms. Connie Durante, Parish Manager
1300 Leslie Street
Toronto, Ontario M3C 2K9
Prepared By:
Halcrow Yolles
Queen’s Quay Terminal, 207 Queens Quay West
Suite 550, PO Box 132
Toronto, Ontario M5J 1A7
Project No.: T070612
November 2007
Page i
Project No. T070612
November 7, 2007
EXECUTIVE SUMMARY
Halcrow Yolles was retained by Ms. Connie Durante, on behalf of St. Bonaventure’s Church to perform a roof
condition assessment of select buildings at the property located at 1300 Leslie St. A roof replacement strategy
was developed along with options for incorporating sustainable strategies into the roof replacement
program. The scope of services also included a review of the church’s mechanical systems.
Halcrow Yolles conducted a document review and an investigative program to determine the construction
and condition of the roofs on the main church and Parish Centre. The church skylights and masonry cross
structure were also reviewed.
The observed condition of the sloped roofs and skylights requires their
immediate replacement. The flat roofs were found to be in serviceable condition but approaching the end of
their service lives and will require replacement in the near future.
A building energy audit was commissioned and performed by Mr. Rick Takacs, P. Eng., of Baseline Energy
Services. The mechanical equipment at the church was found to be outdated and inefficient as compared to
currently available systems. Upgrades to the mechanical systems will result in improved efficiencies and
reduced operating costs based on fuel savings. The simple payback periods for equipment upgrades ranged
between 4 and 10 years, depending on the system.
Halcrow Yolles researched sustainable strategies such as solar power, green roofs, cool roofs, and natural
ventilation and incorporated these into the roof replacement strategy where feasible. Budget costs were
formulated based on contractor quotations and experience on similar projects. These are summarized below.
Item
2008
1. Replace Sloped Roofs with Cool Metal Roofing System
$
350,000
2. Replace Skylights
$
115,000
3. Install Roof Vents with Motorized Fans for Natural Ventilation
4. Solar Power Feasibility Study
$
$
15,000
7,500
Budget Cost
2009
5. Replace Main Boiler with Integrated Boiler Plant
$
72,000
6. Ventilation Upgrades - Church
$
15,000
7. Ventilation Upgrades - Parish
8. Lighting Upgrades
$
$
85,000
25,000
9. Replace Church Flat Roofs with Cool Roof System
$
255,000
2010
10. Replace Parish Centre Roofs with Cool Roof System
$
325,000
11. Repair Parish Centre Precast Beams
12. Repair Masonry Cross Structure
Annual Total
$
$
$
10,000
45,000
380,000
$
487,500
$
452,000
Yolles Partnership Inc.
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Project No. T070612
November 6, 2007
TABLE OF CONTENTS
1.
INTRODUCTION ....................................................................................................................................................1
1.1
SCOPE OF SERVICE .................................................................................................................................... 1
1.2
BACKGROUND INFORMATION ................................................................................................................... 1
2.
INVESTIGATIVE PROGRAM..............................................................................................................................2
2.1
DOCUMENT R EVIEW ................................................................................................................................. 2
2.2
VISUAL REVIEW ........................................................................................................................................ 2
2.3
EXPLORATORY OPENINGS ........................................................................................................................ 2
2.4
BUILDING ENERGY AUDIT ........................................................................................................................ 3
3.
OBSERVATIONS ....................................................................................................................................................4
3.1
DOCUMENT R EVIEW ................................................................................................................................. 4
3.1.1.
Sloped Roofs (Roofs J, K, L, M, N, and O ).................................................................................................. 4
3.1.2.
Church Flat Roofs (Roofs D, E, F, G, H, and I)...........................................................................................4
3.1.3.
Parish Hall Roofs (Roofs A, B, and C) ......................................................................................................... 4
3.2
VISUAL REVIEW ........................................................................................................................................ 5
3.2.1.
Roof A...........................................................................................................................................................5
3.2.2.
Roof B...........................................................................................................................................................6
3.2.3.
Roof C...........................................................................................................................................................6
3.2.4.
Roof P...........................................................................................................................................................6
3.2.5.
Roofs J,K,L,M,N and O ................................................................................................................................7
3.2.6.
Masonry Cross Structure..............................................................................................................................7
3.2.7.
Skylights .......................................................................................................................................................7
3.3
EXPLORATORY OPENINGS ........................................................................................................................ 8
2.5
MECHANICAL SYSTEMS .......................................................................................................................... 16
4.
COMMENTS AND DISCUSSION .......................................................................................................................17
4.1
ROOFING S YSTEMS.................................................................................................................................. 17
4.1.1.
Cold-Applied Roofing.................................................................................................................................17
4.1.2.
Green Roofs................................................................................................................................................17
Roofs A, B, and C.....................................................................................................................................................18
Roofs E, D, F, and I .................................................................................................................................................19
Roofs G and H .........................................................................................................................................................19
4.1.3.
Metal Roofing............................................................................................................................................. 19
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Project No. T070612
November 6, 2007
4.1.4.
4.2
5.
Cool Roofs..................................................................................................................................................20
SUSTAINABLE STRATEGIES ..................................................................................................................... 20
4.2.1.
Building Operation.....................................................................................................................................20
4.2.2.
Mechanical Systems ...................................................................................................................................21
4.2.3.
Roof-Mounted Solar Energy Collection .....................................................................................................22
4.2.4.
Natural Ventilation.....................................................................................................................................23
4.2.5.
Storm Water Management..........................................................................................................................23
RECOMMENDATIONS .......................................................................................................................................25
5.1
G ENERAL ................................................................................................................................................. 25
5.2
SLOPED ROOFS (ROOFS J, K, L, M, N & O) ........................................................................................... 25
5.3
5.4
SOLAR COLLECTION ON ROOF N ........................................................................................................... 26
5.5
SKYLIGHTS AND ROOF V ENTS ................................................................................................................ 26
5.6
FLAT ROOFS - G ENERAL ......................................................................................................................... 27
5.6.1.
Parish Hall Roofs (Roofs A, B, and C) .......................................................................................................27
5.6.2.
Green Roofs................................................................................................................................................27
5.7
MASONRY SUPP ORT W ALL FOR S TEEL CROSS ...................................................................................... 28
5.8
PHASING................................................................................................................................................... 29
6.
CONSTRUCTION BUDGET ESTIMATES........................................................................................................30
6.1
SLOPED ROOFS (ROOFS J, K, L, M, N & O) ........................................................................................... 30
6.1.1.
6.1.2.
6.2
Option A – Metal Shingles..........................................................................................................................30
Option B – Standing Seam..........................................................................................................................30
SKYLIGHTS AND ROOF V ENTS ................................................................................................................ 31
6.2.1.
Skylights .....................................................................................................................................................31
6.2.2.
Roof Vents ..................................................................................................................................................31
6.3
6.4
SOLAR THERMAL COLLECTION ON ROOF N.......................................................................................... 32
6.5
CHURCH FLAT ROOFS (ROOFS D, E, F, G, H, I AND P).......................................................................... 32
6.5.1.
6.6
Green Roof Option – Roofs D, G, H, and I ................................................................................................32
PARISH H ALL ROOFS (ROOFS A, B, AND C)........................................................................................... 33
6.6.1.
Green Roof Option – Roofs A and C ..........................................................................................................33
6.7
PARISH H ALL EXPOSED PRECAST C ONCRETE BE AMS .......................................................................... 34
6.8
MASONRY CROSS S TRUCTURE................................................................................................................ 34
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Project No. T070612
November 6, 2007
1.
INTRODUCTION
1.1
Scope of Service
Yolles was retained by Ms. Connie Durante on behalf of St. Bonaventure’s Church to perform a
roof condition assessment of the property located at 1300 Leslie St.
The assessment also
includes a review of the church’s mechanical systems. A roof replacement strategy will be
developed along with options for incorpor ating sustainable strategies into the roof replacement
program.
1.2
Background Information
St. Bonaventure’s Church , constructed circa 1959, is located on the west side of Leslie Street,
south of Lawrence Avenue. The buildings included in this review were the main church and
the Parish Centre. The site has ample green space and is bordered by a forested ravine (Wilket
Creek Park) to the south and west. To the north of St. Bonaventure’s Church is a catholic
elementary school that bears the same name; a parking lot is situated between the buildings.
The main church has a cruciform floor plan and high, steeply-pitched roofs over the worship
and alter areas. Six skylights line the ridge of the church, providing natural daylighting to the
worship area below. The side chapels and rear of the church have flat roofs. At the front of the
church is a courtyard surrounded by a covered walkway. A large steel cross and its masonry
support structure are located within the courtyard.
Covered walkways flank the church
adjacent to the main worship area.
The Parish Hall consists of three contiguous single-storey buildings, all of which have flat
roofs. The original hall, located to the east, is the tallest and has 8 precast concrete beams that
project beyond the roof overhang. To facilitate referencing of the various roofs, we have
labelled them alphabetically. We recommend reviewing the report in conjunction with the
attached Roof Key Plan to accurately identify the roofs discussed.
Because of the characteristics of the roofs and the site’s context, there is an opportunity to
incorporate sustainable strategies as part of the roof replacement program. For example, the
south-facing pitched roof over the main worship area is an ideal candidate for a solar collection
system, which could provide renewable on-site energy to offset heating or electricity costs.
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Project No. T070612
November 6, 2007
2.
Investigative Program
The following is a summary of the investigative program developed to perform the assessment
of the roofing systems.
2.1
Document Review
Available base building drawings, reports relevant to the roofing of the property were
reviewed. The documents reviewed included the following:

Architectural Drawing Set, prepared by Fisher, Tedman & Fisher Architects, dated
March 1958.

Condition Survey of Roof Systems, prepared by CSA Building Sciences Ltd., dated July
1989.

Roof Inspection – Parish Centre, prepared by Tremco Roofing Division, dated December
7, 1989.

Roof Inspection – Parish Centre Re-Roofing and Thermal Scan, prepared by Tremco
Roofing Division, dated June 7, 1990.

St. Bonaventure Church Roof Assessment, prepared by Morrison Hershfield Ltd., dated
December 11, 2006.
2.2
Visual Review
A visual review of the roof assemblies was performed from the various roof levels.
2.3
Exploratory Openings
Seven exploratory roof openings were performed and facilitated by Dean-Chandler Roofing
Limited in our presence, between September 24 and 25, 2007. Two exploratory openings were
performed in the masonry support tower for the cross, facilitated by The Restorers Group Ltd.
in our presence on September 24, 2007. We did not perform exploratory openings in the roofs
which Morrison-Hershfield had already investigated.
For each roof opening, a section of the roofing system measuring approximately 6” x 6” was
cut and removed in order to review of the underlying substrate and to confirm the condition of
the removed membrane with respect to pliability, deterioration, etc. The construction of the
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Project No. T070612
November 6, 2007
roof was verified and its condition assessed. Samples were collected for future reference.
After completing our observations, the membrane was repaired using a compatible system.
Any removed insulation and overburden material was reinstated.
For each opening in the masonry, between 3 and 4 bricks were removed in order to review the
underlying structural steel. After completing our observations, the openings were repaired
with new brick and mortar to match existing conditions.
2.4
Building Energy Audit
We commissioned a Building Energy Audit for the buildings at St. Bonaventure’s Church,
which was conducted by Mr. Rick Takacs, P.Eng., of Baseline Energy Services. The audit is
appended at the end of this report.
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Project No. T070612
November 6, 2007
3.
OBSERVATIONS
The site observations were performed between September 24 and September 25, 2007. Weather
conditions at the time were sunny and 25°C.
To facilitate referencing of the various roofs, we have labelled them alphabetically.
We
recommend reviewing the report in conjunction with the attached Roof Key Plan to accurately
identify the roofs discussed.
3.1
Document Review
3.1.1.
Sloped Roofs (Roofs J, K, L, M, N, and O )
The architectural drawings show the original construction of the sloped roof as 2X6 vee-joint
wood deck, ½” wood fibre insulation, and asphalt shingles. The documents reviewed suggest
the sloped roofs were last replaced circa 1989.
The Morrison Hershfield report (2006)
recommended the current roof be replaced.
3.1.2.
Church Flat Roofs (Roofs D, E, F, G, H, and I)
The architectural drawings show the original construction of the church flat roofs as 1” wood
roof deck, 1” rigid insulation, and felt and gravel (4-ply felt-and-coal-tar-pitch built-up) roof.
According to the Morrison Hershfield report, the two flat roofs over the transept (Roofs H and
G) have been re-roofed with a ballasted loose-laid EPDM membrane and the sanctuary (Roof I)
has been reroofed with a 4-ply BUR. In all cases the original roof was left in place and the new
systems installed over top. Morrison Hershfield observed moisture within the overlaid roofs
and recommended their replacement in the short term.
3.1.3.
Parish Hall Roofs (Roofs A, B, and C)
The drawing set reviewed was incomplete with respect to the Parish Hall.
The roof
composition of the original hall (Roof A) is included in the church architectural set; however,
no drawings could be reviewed for the additions to the hall (Roofs B and C). The architectural
drawings show the original construction of the Parish Hall roof as a felt and gravel roof over
2½“ Tectum deck. The Tremco report (1989) indicates that the Parish Hall had an additional
BUR installed prior to 1989.
A thermal scan conducted by Tremco in 1990, confirmed
membrane failure at Roofs A and C.
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Project No. T070612
November 6, 2007
3.2
Visual Review
A visual review of all the roofs included in the scope was conduc ted. The visual review
included an exterior review from the roofs themselves to observe the condition of the
membrane and flashing, the presence of any mechanical installations or penetrations, as well as
drainage. An interior review was also conducted to observe the condition of the roof deck,
where exposed. An interior and exterior review of the skylights was also conducted but from a
distance, as access to these was problematic. The masonry cross structure was reviewed from
the ground and from scaffolding erected to a height of approximately 30 feet.
3.2.1.
Roof A
At the time of our review, Roof A was clear of standing water. Sediment deposits in some
areas of the roof indicate that ponding occurs during rainfall events.
A blister measuring
approximately 1m long by 30cm wide was observed in the north -east area of the roof. Several
ridges were also observed at various locations. Blueberries, a condition where asphalt bleeds
up through the pea -gravel cover, were observed. Blueberries indicate aging of the roof; and
the exposed asphalt is now subject to UV degradation.
This roof has a total of five perimeter drains. Three of the drains penetrate the soffit and drain,
via a downspout , to ground level. The other two are scupper drains which drain onto Roof B.
Gravel traps were not installed at the scupper drains.
A mechanical duct was observed running from the centre of the roof toward the east edge. The
duct is supported with wood sleepers on FR-40 membrane.
The roof structure consists of 9 precast concrete beams which project beyond the roof. The
beams are exposed to the exterior and are demonstrating superf icial signs of deterioration due
to water. This deterioration includes peeling paint and hairline cracking of the concrete. The
beams were sounded with a hammer, and the concrete was found to be sound, with no
delaminations or spalling. A drip edge was observed on the beams, which helps shed water
and prevents the underside from wetting.
The underside of the Tectum deck was reviewed where it was exposed in the stage area. There
were no visible signs of deterioration. It is our understanding that no leaks have been reported
at this roof. Our observations are in agreement with those stated in Morrison Hershfield report
(2006).
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Project No. T070612
November 6, 2007
3.2.2.
Roof B
At the time of our review, Roof B was clear of standing water. Sediment deposits in some
areas of the roof indicate that ponding occurs during rain events. A few isolated cases of
ridging and blueberries were observed. The roof is drained through one internal drain. An
expansion joint is located at the west edge of the roof adjacent to Roof C. The exposed portion
of the joint is constructed of FR-40 membrane which has been painted white. The roof has
several mechanical installations and penetrations, including stack pipes and ducts. The wood
deck could not be reviewed from the interior as it is concealed by the ceiling.
understanding that no leaks have been reported at this roof.
It is our
Our observations are in
agreement with those stated in Morrison Hershfield report (2006).
3.2.3.
Roof C
At the time of our review, Roof C was clear of standing water. Sediment deposits in some
areas of the roof indicate that ponding occurs during rain events.
Ridging measuring
approximately 2” wide by 3 feet long was observed exposing the asphalt to UV degradation.
Isolated instances of blueberries were also observed. The roof is drained through one internal
drain. An expansion joint is located at the east edge of the roof adjacent to Roof B. The roof
has several mechanical installations and penetrations, including stack pipes and ducts. The
wood deck could not be reviewed from the interior as it is concealed by the ceiling. It is our
understanding that no leaks have been reported at this roof.
Our observations are in
agreement with those stated in Morrison Hershfield report (2006).
3.2.4.
Roof P
At the time of our review, Roof P was clear of standing water. Sediment deposits in some areas
of the roof indicate that ponding occurs during rain events. The roof drains via two scuppers
on to Roofs J and K. A segment of flashing was observed to be loose above Roof L. The joints
in the modified bitumen membrane were well sealed, showing a few millimetres of bleed-out.
There are no penetrations or mechanical installations on this roof.
The underside of the roof was reviewed using binoculars from the altar area. We noted pitch
from the original roofing seeping through the wood deck and staining the rafters and carpet
below. It is our understanding that no leaks have been reported at this roof.
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Project No. T070612
November 6, 2007
3.2.5.
Roofs J,K,L,M,N and O
These roofs have a pitch of approximately 67°, and are roofed with asphalt shingles. The
shingles exhibited signs of deterioration such as curling, cracking, tearing, and degranulation.
We observed locations where shingles were missing, particularly along the interface of Roof N
with Roof F. Our observations are in agreement with those stated in Morrison Hershfield
report (2006).
3.2.6.
Masonry Cross Structure
Vertical cracks were visible in the masonry structure in line with the steel support s for the
cross and between the masonry cross structure and the masonry shaft behind it. The cracks
extended nearly the full length of the structure.
3.2.7.
Skylights
The skylights located at the ridge between Roofs N and O were reviewed visually from the
interior of the church using binoculars and from the exterior atop Roof P. Closer access to the
skylights was not possible with the equipment on hand. The skylights are diamond shaped
and are flush with the plane of the roof. Their construction appear s to consist of wood framing
and coloured glass with a plexiglass cover fastened to the framing. The plexiglass covering
impeded visibility, complicating observation of the assembly beneath.
Several cracked
plexiglass panes were noted along with evidence of repeated retrofit sealant application from
the exterior. Metal flashing has been installed on the ridge; it is our understanding that this
metal is a retrofit application installed concurrently with the plexiglass covers. Parish staff has
reported leaks at some of the skylights.
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Project No. T070612
November 6, 2007
3.3
Exploratory Openings
Opening No. 1
Opening No. 1 was located in the field of Roof A.
Observed Roof
Construction:

Pea gravel

4-ply felt-and-asphalt membrane (built up roof or BUR)

1-1/2” fiberglass insulation

Pea gravel

4-ply felt-and-pitch membrane

2“ Tectum deck
Additional Observations:

No moisture was observed in any of the roofing components.

The felt-and-pitch membrane was well bonded to the Tectum deck. When it was removed,
the upper fibres of the deck were also removed.

Samples of the two roof membranes were bent with manual pressure and were found to be
stiff yet not brittle.
Photograph No. 1
A view of Opening No. 1 showing the two
roof membranes and the exposed Tectum
deck.
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Project No. T070612
November 6, 2007
Opening No. 2
Opening No. 2 was located at the parapet at the south-east corner of Roof A.
Observed Parapet
Construction:

Metal flashing

2-ply membrane flashing

Wood fascia

Cant strip


The fascia and cant strip are built on top of the previous roofing system.

The 2-ply membrane flashing was not mopped with asphalt.

The metal flashing covered the newer fascia and was secured with an s-lock at one end and
fasteners at the other.

The newer fascia board exhibited no evidence of moisture damage or wetting despite being
unprotected by a membrane or preservative.
Photograph No. 2
A view of Opening No. 2 showing the wood
fascia and 2-ply membrane flashing which
was not mopped with asphalt.
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Project No. T070612
November 6, 2007
Opening No. 3
Opening No. 3 was located in the field of Roof G.
Observed Roof
Construction:

1” River stone

Single-ply loose-laid EPDM membrane

½” Fibre board

Pea gravel

4-ply asphalt BUR

2” fibre board

Asphalt mopped paper VR

Wood deck


The asphalt BUR was well bonded to the fibre board.

The vapour retarder was well bonded to the wood deck.

A sample of the BUR membrane was bent with manual pressure and was found to be stiff
yet not brittle.
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Project No. T070612
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Opening No. 4
Opening No. 4 was located at the west side of Roof B, adjacent to the expansion joint.
Observed Roof
Construction:

Pea gravel

4-ply asphalt BUR

½” Fibre board

1” phenolic foam insulation

Kraft paper vapour retarder

Tongue-and-groove wood deck


Photograph No. 4
A view of Opening No. 4 showing the two
roof membranes and the tongue-and-groove
wood deck. The wood deck was dry to the
touch and did not exhibit any evidence of
wetting.
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November 6, 2007
Opening No. 5
Opening No. 5 was located at the east side of Roof C, adjacent to the expansion joint.
Observed Roof
Construction:

Pea gravel

4-ply asphalt BUR

2” cellulose fibre insulation


Wood deck


The cellulose fibre insulation was very friable and crumbled in the hands with slight
pressure.

Photograph No. 5
A view of Opening No. 5. The grey matter
visible around the opening is the cellulose
fibre insulation.
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Opening No. 6
Opening No. 6 was located in the field of Roof O, approximately 5 feet from the interface with
Roof E.
Observed Roof
Construction:

Asphalt shingles overlapped at thirds.

Peel-and-stick vapour retarder on the bottom 5 feet of the roof.

Kraft paper vapour retarder from the 5 foot mark to the ridge.

Plywood.

Wood roof deck.


There were three roofing nails in each asphalt shingle.

The underlying plywood substrate exhibited no evidence of moisture.
Photograph No. 6
A view of Opening No. 6.
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Project No. T070612
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Opening No. 7
Opening No. 7 was located in the centre of Roof P.
Observed Roof
Construction:

2-ply thermofusible modified bitumen membrane.

Asphaltic protection board.

2-1/2” fibre board

4-ply pitch BUR

½” Fibre board


Wood roof deck


The modified bitumen membrane was well bonded to the protection board.

The self-adhering protection board was not adhered to the fibre board because its
polyethylene backing had not been removed.

A sample of the modified bitumen membrane was bent with manual pressure and found
to be flexible.

A sample of the BUR membrane was bent with manual pressure and was found to be stiff
yet not brittle.
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Opening No. 8
Opening No. 8 was located in the masonry support tower of the cross around a strut that
connects the cross to the embedded steel structure.
Photograph No. 8
The steel angle is welded to a steel H-section (measuring approximately 4” X 4” encased within
the masonry. The masonry in front of the H-section is 1 wythe thick. The masonry enclosure
has been filled with masonry rubble. Surface corrosion was observed on the steel encased in
the masonry; however, no expansive corrosion products were observed. The cracking in the
brick was observed to occur directly over the steel column.
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Opening No. 9
Opening No. 9 was located in the masonry support tower of the cross midway between two
steel struts and approximately 3 feet above Opening No. 8.
Photograph No. 9
The opening revealed the steel colum n. Surface corrosion was observed on the steel; however,
no expansive corrosion products were observed. The corroded piece of steel on top of the
column and visible in the photograph (indicated with the arrow) was too large to be composed
of corrosion products.
The masonry enclosure has been filled with masonry rubble. The
cracking in the brick was observed to occur directly over the steel column.
2.5
Mechanical Systems
Please refer to the appended Building Energy Audit for observations pertaining to the
buildings’ mechanical systems.
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4.
COMMENTS AND DISCUSSION
The following is an introductory discussion on various roofing systems and sustainable
strategies that could be incorporated into the roof replacement program at St. Bonaventure’s
Church. Our recommendations are given in the following section.
4.1
Roofing Systems
4.1.1.
Cold-Applied Roofing
Cold-applied roofing systems generally consist of an adhesive and a membrane, which are
applied to the roof deck in one or more plies for redundancy. Cold-applied systems can have
fewer odours than hot-mopped or torched-on systems as well as greater ease of installation
which allows for better quality control and reduced labour costs.
The material costs are
generally higher than hot-applied systems, which results in a similar overall project cost. Some
cold-applied systems can be installed in sub-zero temperatures, which can be advantageous
under certain scheduling requirements.
4.1.2.
Green Roofs
Green, or vegetated roofs, are roofs that incorporate vegetation into the roofing system. Green
roofs have both macro- and micro-level benefits. In urban areas, green roofs reduce the urban
heat island effect by capturing solar energy through photosynthesis and cooling the
surrounding environment through evapotranspiration. They alleviate demand on municipal
storm water systems by delaying the release of runoff and by retaining rainfall to be used in
the plants’ biological processes or evaporated directly to the atmosphere.
The vegetation
provides a habitat for birds, insects, and other wildlife and helps filter and clean the air. When
visible from surrounding buildings, green roofs provide improved city views and can elevate
the public’s sense of well-being.
At the micro level, green roofs can provide much needed green space to hig hly urbanized sites.
In commercial applications, v iews and access to a green roof can improve occupant
productivity and reduce absenteeism. By intercepting incident solar energy and providing
cooling through evapotranspiration, green roofs can reduce building cooling costs. Added
protection and reduced thermal stress to the roof membrane can extend its life significantly
compared to a conventional roof, as currently used on this site.
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Because of the added weight of retained storm water, growing media, and vegetation, green
roofs impose a greater load on a building’s structure than do conventional roofing systems. In
a retrofit application, a structural analysis is necessary to determine whether a roof’s existing
capacity is sufficient to support a green roof. Green roofs also require greater maintenance
costs than do conventional roofs as the vegetation needs to be maintained and irrigated.
However, to be true to the principles of sustainability, green roof design and plant species
selection should be such that once the vegetation is established, it can survive with minimal
maintenance and little or no supplemental irrigation.
Green roof systems can be planted-in-place or pre-grown (supplied in mats or trays).
Regardless of the system used, the City of Toronto Green Development Standard recommends
at least a 6” depth of growing medium (to improve plant survivability) and a non-monoculture
planting scheme. Using a lightweight growing medium and extensive plantings, a system such
as this one would add an additional load of 20psf (pounds per square foot) to the roof.
The City of Toronto currently offers an incentive program in the amount of $50/m2 to recognize
the benefits of green roof installation. The incentive is available to any private building owner
that meets the program’s requirements. With an appropriate system and sufficient green roof
coverage, we believe that St. Bonaventure’s Church would be eligible for this credit. The credit
represents approximately 25% of the additional cost of a 20psf extensive green roof.
Green roofs are more expensive than conventional roofs but they can provide benefits which,
depending on how the owner values them, can offset the additional cost. Green roofs can also
be cost-feasible from a life cycle costing perspective. Green roofs can extend the life of the
waterproofing membrane thereby diminishing the frequency of replacement cycles. While the
service record of green roofs is unproven in North America, in Germany, where green roofs
have been installed for 50 years, they are expected to last 40 years. When compared to a 20
year life span for a conventional system, the increased initial cost of a green roof can be costfeasible from a life cycle costing perspective.
Roofs A, B, and C
The drawings reviewed did not contain structural information for these roofs.
We can
recommend a design load equivalent to the removal of one layer of built-up roofing and gravel
and the difference in snow loading requirements between past building codes and the present.
Based on these assumptions, Roofs A and C should be capable of supporting green roofs with a
saturated weight of 20psf. Because of snow accumulation on Roof B adjacent to Roof A, this
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roof would not be able to support any additional loading. The actual loading capacity of these
roofs can only be verified by field-measuring the structural members and conducting a full
structural analysis.
Roofs E, D, F, and I
Based on the drawings reviewed, our structural analysis indicates that Roofs D, E, F, and I
would be capable of supporting green roofs with a saturated weight of 20 psf. The actual
loading capacity of the roof can only be verified by field-measuring the structural members
and conducting a full structural analysis.
Roofs G and H
The drawings reviewed did not contain structural information for the open-web steel joists
framing this roof. They are a proprietary product manufactured by Dominion Bridge, and to
our knowledge there is no catalogue available for these. However, we can recommend a
design load equivalent to the removal of one layer of built-up roofing and ballast and the
difference in snow loading requirements between past building codes and the present. Based
on these assumptions, these roofs should be capable of supporting green roofs with a s aturated
weight of 20psf. The actual loading capacity of the roof can only be verified by field -measuring
the structural members and conducting a full structural analysis.
4.1.3.
Metal Roofing
Metal roofing systems are usually made of steel or aluminium alloys and are generally
protected by a galvanic or other corrosion-inhibiting coating. They are available in a wide
range of colours, textures, and styles and are often made to mimic traditional roofing materials
such as cedar shakes or slate. The primary benefit to metal roofs is their durability. Many
metal roofing manufacturers offer 50-year warranties on their products when installed in
institutional applications. In comparison, asphalt shingles have an expected service life of 20
years at the upper range. Because metal roofs are a premium system, they are more expensive
than their conventional counterparts. However, because of their durability, they are often well
worth the increased initial investment on a life cycle costing basis. A longer service life also
has the advantage of reduced disruption to building occupants and the generation of less
demolition waste. Metal roofs also have additional sustainability benefits including recycled
content (typically 25%) and 100% recyclability.
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4.1.4.
Cool Roofs
Cool roofs incorporate materials with a higher solar reflectance and higher thermal emissivity
than conventional roofs.
This combination of properties minimizes a roof’s heat gain by
reflecting a greater proportion of the incident solar radiation and increasing the roof’s relative
ability to emit absorbed heat. The reduction in heat gain can translate to a cost savings in
cooling and HVAC equipment needs for a building. In addition, cool roofs can increase
membrane life by decreasing the magnitude and range of thermal stress. Cumulatively, the
wide-spread implementation of high-reflectance, high-emissivity surfaces would reduce the
urban heat island effect and further reduce cooling costs.
Many conventional roofing systems, such as built-up roofs, modified bitumen, metal, and
single-ply membranes, are all available as cool roofs. Many of these systems can be made to
incorporate high-reflectance, high-emissivity materials or coatings with very little change in
design, installation, and maintenance. Therefore, the cost of implementing cool roofs can be
equal to or just slightly greater than conventional roofs. Any additional initial expense is often
recovered within an acceptable payback period through savings in cooling and HVAC
equipment costs. Green roofs are also considered cool roofs.
The most commonly accepted rating system for cool roofs is the EnergyStar rating system
administered by the US Environmental Protection Agency.
Many roofing suppliers and
installers in Canada offer EnergyStar-rated cool roofing products.
4.2
Sustainable Strategies
4.2.1.
Building Operation
Life cycle environmental impact analyses show that a building’s largest environmental impact
results from building operation, specifically, the energy used for space heating and cooling,
lighting, domestic hot water, and other building processes. These environmental impacts also
represent a significant monetary cost – the cost of energy – to building owners. By reducing
energy consumption, owners can reduce their environmental impact while saving money.
At St. Bonaventure’s Church, a reduction in energy use could result from an improved
integration of several building systems and processes including space heating and cooling,
ventilation, the building envelope, and solar energy collection.
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The building envelope separates the interior environment from the exterior and includes such
components as the walls, roofs, windows, and skylights. The ability of the envelope to control
air leakage, vapour diffusion, and the conduction and transmission of heat contributes to the
occupants’ comfort and the cost of conditioning the interior space. The building envelope is a
system; however, only the roofs and skylights are included in the scope of this report.
Building insulation retards the conduction of heat t hrough the building envelope. In the
winter, it helps to keep heat in, reducing heating costs. Conversely, in the summer, it helps to
reduce heat gain and cooling costs. The addition of insulation at St. Bonaventure’s Church
would reduce the amount of energy required to heat the building.
However, in retrofit
situations, it is not always feasible because of constructability or budgetary limitations.
In our opinion, the addition of insulation on the roofs at St. Bonaventure’s Church, is both
constructable and will result in reduced heating costs. Similarly, replacement skylight units
are available that are double-paned and gas-filled with low-emissivity coatings to further
reduce heat loss. The installation of insulation in the roofs and energy-efficient skylights is
discussed in more detail in the Recommendations section.
The other elements of the building envelope are beyond the scope of this report. However,
these should be considered in any future discussion on sustainable strategies and should be
included in the long-term building management plans for the parish.
4.2.2.
Mechanical Systems
Mechanical systems provide conditioning (heating or cooling) and supply fresh ventilation air
to interior spaces. The efficiency of these systems is a major contributor to overall building
operating efficiency. For a complete discussion on the buildings’ mechanical systems and
energy use, please refer to the Building Energy Audit appended at the end of this report.
In summary, the churches mechanical systems are outdated and are inefficient when compared
to current equipment. Energy savings through improved operating efficiencies can be realized
by upgrading the equipment and controls. For all the units reviewed, the economic savings
from reduced energy consumption resulted in simple payback periods of less than 10 years.
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4.2.3.
Roof-Mounted Solar Energy Collection
The south-facing sloped roof of St. Bonaventure’s main church is ideal for solar energy
collection (Roof N). It has an area of 4,000ft2, no shading, and an angle of inclination of 67°,
which optimizes it for winter-time collection.
There are two primary methods of solar
collection: photovoltaic and thermal.
Photovoltaic or PV converts the sun’s energy directly into electricity which can then be used in
the building, stored in battery banks, or sold to the grid. Of these options, integration with the
grid is the most attractive as it ensures a reliable supply of electricity and does not require large
banks of batteries that require maintenance, periodic replacement, and have detrimental
environmental effects.
In Ontario, there are two publicly funded programs to encourage PV technology. The first is
net metering which is a regulation introduced by Ontario Ministry of Energy. Net metering
allows small scale generators of alternative energy to sell their excess energy to the grid. At the
end of the month, their utility company bills them for their net electricity consumption. If they
produced more energy than they consumed then they receive a credit which can be carried
forward for up to a year.
The second program is offered by the Ontario Power Authority (OPA) and is called the
Standard Offer Program. Under this program, small scale producers of PV electricity can sell
their power to the OPA for 42¢/kW•hr. Conventional electricity is purchased as usual from the
utility company (approximately 11¢/kW•hr). Even with the Standard Offer Program, simple
payback periods for typical PV systems in southern Ontario, are in excess of 30 years.
Solar thermal energy collection is less costly than PV and can capture a greater portion of the
incident solar radiation for building use. In the case of St. Bonaventure’s Church, solar thermal
collection is more attractive than PV because of the building’s geometry, layout, and heating
requirements. St. Bonaventure’s Church has a hydronic heating system which not only serves
the main church, but also supplies heating water to the parish centre. Solar thermal collection
could be used to heat the radiator water and displace purchased natural gas fuel. At 67° above
the horizontal, the slope of the roof is optimized for collection during the heating season.
Furthermore, the proximity of the boiler room to the roof would further facilitate integration of
the solar collection system with the heating plant. Currently combined federal and provincial
subsidies offset the total cost of design and installation of solar thermal systems by 50%.
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It must be noted that the installation of solar collectors on the church’s roof will alter its
appearance. An additional benefit of solar collectors is that they will intercept solar energy in
the summer thereby reducing heat gain through the roof.
4.2.4.
Natural Ventilation
Natural ventilation could increase the comfort of parishioners in the summer without
mechanical conditioning. By venting near the ridge of the church, spent hot and humid air
would exhaust at the roof peak and fresh air would be drawn in through open windows and
doors at ground level. Natural ventilation could be achieved by installing operable skylights
with ground-level controls or vents with motorized fans. Through communication with a
custom skylight fabricator, we determined that operable skylights are not a feasible option due
to their complex geometry and location at the ridge. Roof vents with motorized fans are a
viable option and would achieve a similar effect more cost effectively. Solar-powered units are
available which would eliminate the need for interior electrical wiring.
4.2.5.
Storm Water Management
While not included in our scope of work, we feel that any discussion on sustainable roofing
strategies is not complete without consideration for storm water management. This is because
storm water runoff is a problem caused by replacing natural topography (soil and vegetation)
with impermeable surfacing (roofs and paving). The increase in impermeable surfacing in
urban areas causes environmental stress by preventing precipitation from slowly filtering
through the soil into the water table and instead, diverting it directly into rivers and streams.
As rainwater washes over roads and parking lots, it becomes contaminated with car fluids,
landscaping chemicals, and other pollutants before discharging into natural watercourses. The
managing of stormwater requires a significant amount of costly municipal infrastructure,
including sewers, storage tanks, filtration ponds, etc.
By integrating site stormwater management with landscaping irrigation requirements,
stormwater run off can be reduced, relieving stress on municipal storm systems and the
environment and conserving potable water. On a site such as St. Bonaventure’s Church, with
ample green space, landscaping irrigation requirements, and approximately 20,000 sq. ft. of flat
roof area, the opportunity exists to capture and retain storm water for irrigation use and
reduce site run off by as much as 100%. To determine the trade-off between the potential
benefits of rainwater diversion and storage, and the cost of implementing these measures,
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would require a stormwater run-off study and coordination with the landscaping design of the
church grounds.
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5.
RECOMMENDATIONS
5.1
General
The flat roofs reviewed consist of two roofing systems installed over one another. The first is
likely the original roofing which was left in place when the bu ildings were re-roofed,
approximately 20 years ago, or more, in the case of the Parish Hall (Roof A). Based on our
observations and exploratory openings, it is our opinion that the flat roofs are approaching the
end of their service lives and will need replacement in the near future. According to the
documents reviewed, the asphalt-shingle roofing on the sloped roofs (Roofs J, K, L, M, N, and
O) is approximately 20 years old. This age is consistent with the observed condition of the
roofs.
In our opinion, the sloped roofs are at the end of their service lives and require
immediate replacement (2008).
A phased approach for the replacement of the roofing is
therefore recommended.
5.2
Sloped Roofs (Roofs J, K, L, M, N & O)
We recommend the sloped roofs, which are currently roofed with asphalt shingles, are
replaced with a metal roofing system. The existing roof should be removed up to the plywood
substrate, which was observed to be in serviceable condition. We recommend the construction
of the new roof to consist of:

Self-adhered vapour retarder

3” galvanized Z-girts

3” rigid insulation laid between Z-girts

½” exterior grade plywood sheathing

Self-adhered ice and water shield

High-reflectance, high emissivity (cool roof) metal roofing system (either standing seam or
metal shingle).
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5.3
Mechanical Systems
For complete recommendations for the buildings’ mechanical systems and energy use, please
refer to the Building Energy Audit appended at the end of this report. We recommend the
base building upgrades as outlined in the energy audit. These include:
5.4

Replace the boiler (located in the church basement) with an integrated boiler plant

Upgrade the church ventilation systems

Upgrade the parish ventilation systems

Upgrade lighting systems
Solar Collection on Roof N
The geometry of Roof N and its proximity to the heating plant makes it an ideal candidate for a
solar thermal collector.
However, greater environmental benefit and more cost-effective
energy conservation measures can be achieved through the base mechanical upgrades outlined
above. A solar collector would be an excellent option to consider for further improvements in
energy efficiency after (or concurrently with) implementing the upgrades to the heating plant
and ventilation systems. We recommend a detailed feasibility study to quantify the potential
energy savings and weight them against the system costs. Should the study prove favourable,
it would be followed by a design phase in order to size a solar system and integrate it with the
existing building mechanical systems.
5.5
Skylights and Roof Vents
We recommend the skylights are replaced concurrently with the sloped roofs to facilitate
access. Because operable units are not feasible, we recommend roof vents with motorized fans
are installed to promote natural ventilation of the worship area. The skylights should be
replaced with low-emissivity-coated argon-filled units to match their current configuration.
Wooden curbs will be required around the openings to compensate for the height of the new
roof insulation and to provide an adequate substrate for a continuous and watertight tie-in of
the building envelope components. Because of their location at the roof ridge and their nonstandard shape, the new skylights will have to be custom fabricated.
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5.6
Flat Roofs - General
Our review of the flat roofs at St. Bonaventure’s church found that all of the roofs have two
roofing systems installed. While leaving the existing roofing in place reduces removal and
disposal costs, it increases the load on structural members. We recommend that both existing
roofs are removed as part of any future re -roofing work. Removing all the existing roofing
allows the new roof to be installed over a reliable substrate which is important to the durability
of the new system. The recommended construction of the new roof is as follows:

Vapour retarder

2.5” rigid insulation

½” fibreboard

3-ply cold-applied built-up roof

High-reflectance, high emissivity top coat and aggregate (cool roof)
We recommend the cold-process system because it has fewer undesirable odours than
conventional hot systems, allowing the church to continue operating with less disruption. A
cool roof system will reduce heat gain and cooling costs over conditioned spaces. All flashings,
drains, soffits, and mechanical supports should be replaced concurrently with the roof
replacement work.
5.6.1.
We recommend the addition of sloped insulation on Roofs A, B, and C because of their size
and the evidence of water ponding observed.
Sloped insulation facilitates drainage and
prevents water from ponding on the membrane, reducing the potential for leaks to occur.
5.6.2.
Green Roofs
Our structural analysis (subject to the assumptions stated above) shows that vegetated roofs
with a saturated weight of up to 20 psf could be installed on Roofs A, C, D, G, H, and I without
requiring any structural reinforcement. This loading would allow for a semi-intensive system
with up to 6” of lightweight growing medium and would comply with the City of Toronto
Green Development Standard. The church would likely qualify for the City’s Green Roof
Incentive Program which would help offset some of the additional cost. The cost of installing
such a system is approximately $25/sq. ft. in addition to the insulation, membrane and other
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conventional roofing components. The cost can vary widely based on plant species selection
and maturity.
The decision to install green roofs must be made by weighing the additional costs against the
potential benefits. In this case, some of the benefits often associated with urban green roofs,
such as site beautification, improved air quality, and increased worker productivity and
morale, are all achieved by the site’s current features such as the well-kept grounds and
proximity to the Wilket Creek ravine. As single storey buildings with no surrounding highrises, there is little opportunity for overlook to the roofs. Green roofs can also render a cooling
effect in the summer which can reduce air conditioning costs. However, this benefit can also
be achieved more cost effectively with a cool roof.
While green roofs are structurally possible on some of the flat roofs at St. Bonaventure’s
Church, it is our opinion that their benefits do not outweigh their costs, and that other
sustainable strategies, such as updating the mechanical systems, installing a solar thermal
collector, cool roofs, and roof vents, would result in more cost-effective environmental benefits.
We have included green roofs as an option in our budget cost estimates in the next section.
5.7
Masonry Support Wall for Steel Cross
We determined that the vertical cracks in the masonry cladding of the metal cross support
tower are the result of the movement of the cross structure. The movement is a normal
behaviour caused by wind loading and is not cause for concern as the steel structure is capable
of withstanding the forces. However, the steel structure has been encased in brick masonry
which does not possess the same elasticity as steel. Because this configuration does not allow
for differential movement between the materials, any displacement of the steel stresses the
masonry, causing it to crack.
The cracked masonry units can be replaced to correct the walls’ appearance, but if the cause is
not addressed, they will simply crack again. To rectify the condition which causes the cracking
the masonry tower must be rebuilt in such a way as to allow differential movement between
the steel and the brick. At locations were support struts penetrate the masonry, a gap should
be left around the strut and sealed with a watertight detail that accommodates movement.
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5.8
Phasing
Phasing of roof replacement work has advantages and disadvantages which need to be
assessed with respect to the Client’s needs and budget. Phasing allows for the cost of the roof
replacement to be spread over several years. Roofs that are in the poorest condition can be
prioritized while roofs that are still serviceable can be deferred. Phased roofing replacement
might create a prolonged annoyance to building users; and i t could be advantageous, in some
cases, to do all the work at once.We recommend the following phased approach for roofing
replacement work at St. Bonaventure’s Church:
Phase 1 (2008) – Replace the sloped roofs of the main church (Roofs J, K, L, M, N, and O) and
the skylights. It is our opinion that the condition of these roofs indicates that they have
reached the end of their service lives. After replacing the sloped roofs, the church’s flat roofs
(Roofs D, E, F, G, H, I, and P) should be replaced. This s equencing will ensure that the lower
roofs are not damaged by overhead work.
Phase 2 (2010) – Replace the Parish Centre roofs (Roofs A, B, and C) and rehabilitate the
exposed concrete beam projections.
As discussed above, the phasing of the work will dep end on the Client’s needs and budget. If
desired and financially feasible, the phases can be compressed.
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6.
CONSTRUCTION BUDGET ESTIMATES
Our estimate of repair costs associated with our recommendations is base d on the Parish Hall
and church roofs reviewed. Although we consulted with various contractors and material
suppliers, the project costs can only be ascertained with the preparation of bid documents for a
defined scope of work and competitive bidding to r eflect market conditions. Cost estimates
provided assume the work is tendered in late winter or early spring of a given year. Refer to
Table 1 for a summary of the estimated costs, which do not include G.S.T..
6.1
Sloped Roofs (Roofs J, K, L, M, N & O)
The work recommended for these roofs is:
6.1.1.

Removal and disposal of the existing roof system down to the plywood substrate,
including all flashings and soffits, and the canopies over mechanical equipment on Roof I .

Installation of a new roofing system as described in our recommendations with either a
metal shingle or standing seam roofing system.

Installation of all associated trim flashings, valley flashings, soffits, etc.

Installation and removal of temporary jacks and tie-off anchors to facilitate access.
Option A – Metal Shingles
We estimate the cost of the above work with a metal shingle system to be $460,000.
6.1.2.
Option B – Standing Seam
We estimate the cost of the above work with a standing seam system to be $350,000.
Both systems include a 50 -year materials warranty. System selection will depend on aesthetic
concerns and budgetary constraints.
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6.2
Skylights and Roof Vents
6.2.1.
Skylights
The work recommended for the skylight replacement is:

Removal and disposal of the existing skylights.

Construction of new skylight curbs to compensate for the depth of the new roofing.

Installation of new custom-fabricated skylights.
We estimate the cost of the above work to be $115,000.
6.2.2.
Roof Vents
The work recommended is:

Installation 7 roof vents with motorized fans near the ridge of the roof on the north side.

Installation of all wiring and controls for the vents.
6.3
Mechanical Systems
For detailed costs for the mechanical systems upgrades, please refer to the Building Energy
Audit appended to this report. Because the mechanical upgrades will result in quantifiable
energy savings, a simple payback period can be calculated as detailed in the table below.
Description of Measures
Integrated Boiler Plant
Ventilation Upgrades - Church
Ventilation Upgrades - Parish
Lighting Upgrades
Estimated Annual Cost Savings
Electrical
Gas
$
6,037 $
9,173
$
1,450 $
2,086
$
8,114 $
2,211
$
7,252
Retrofit Cost
$
72,000
$
15,000
$
85,000
$
25,000
Simple
Payback (yrs)
4.7
4.2
8.2
3.4
Please refer to the Building Energy Audit for the methodology and assumptions used in
producing these figures.
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6.4
Solar Thermal Collection on Roof N
The cost of the recommended feasibility study for a thermal collector on Roof N is estimated to
be $7500. If the budget permits, the installation of a solar thermal collector can be done in
conjunction with the integrated boiler plant upgrade described above. The estimated cost of
adding a solar thermal collector to the boiler plant upgrade is $115,000. This work includes:

Design and installation of a solar thermal collection system consisting of storage tanks,
plate heat exchanger, piping and insulation, and controls.

Integration with the building heating plant.
Note that if the church is eligible for current federal and provincial government subsidies for
solar thermal collection systems, then the above cost would be reduced by 50%.
6.5
Church Flat Roofs (Roofs D, E, F, G, H, I and P)

Removal and disposal of the existing roof system down to the wood deck substrate,
including all flashings, soffits, drains, eaves troughs, and downspouts.

Installation of a new roofing system as described in our recommendations.

Installation of new flashings, soffits, drains, eaves troughs, and downspouts.

Crane access for Roof P.
6.5.1.
Green Roof Option – Roofs D, G, H, and I
The work recommended for the Green Roof Option is:

Field measurement and structural analysis to verify loading capacity of the roofs.

Installation of all green roof components including root resistant layer, drainage layer,
filter cloth, 6” of lightweight growing medium, irrigation system, extensive planting
scheme.

2-year initial maintenance program to ensure the plants become established.
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We estimate the additional cost of the above work to be $32,000 for Roof D, $25,000 for Roofs G
and H, and $37,000 for Roof I. These estimates account for the omission of the cool roof top
coat and aggregate. Depending on the extent of green roof coverage and the system selected,
the church may be eligible for the City of Toronto Green Roof Pilot Program incentive, which
would reduce the above costs by approximately 20%.
6.6

Removal and disposal of the existing roof system down to the wood deck or Tectum deck
substrate, including all flashings, soffits, drains, and downspouts.

Installation of a new roofing system as described in our recommendations (including
sloped insulation).

Installation of new flashings, soffits, drains, and downspouts.
6.6.1.
Green Roof Option – Roofs A and C
The work recommended for the Green Roof Option is:

Field measurement and structural analysis to verify loading capacity of the roofs.

Installation of all green roof components including root resistant layer, drainage layer,
filter cloth, 6” of lightweight growing medium, irrigation system, extensive planting
scheme.

2-year initial maintenance program to ensure the plants become established.
We estimate the additional cost of the above work to be $115,000 for Roof A and $85,000 for
Roof C. These estimates account for the omission of the cool roof top coat and aggregate.
Depending on the extent of green roof coverage and the system selected, the church may be
eligible for the City of Toronto Green Roof Pilot Program incentive, which would reduce the
above costs by approximately 20%.
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6.7
Parish Hall Exposed Precast Concrete Beams
We recommend the rehabilitation of the nine exposed precast concrete beams at the Parish
Hall. This work includes:

Removal of the first 2” of concrete from the exposed surfaces of the beams.

Forming and re-pouring the beams to their original profiles with a polymer-modified
material.

Applying a new coat of paint.

Installing a new drip edge flashing over each beam.
6.8
Masonry Cross Structure
We recommend the rehabilitation of the steel cross masonry support structure. This work
includes:

Erecting approximately 60’ of scaffolding on the east elevation of the wall to facilitate
access. The scaffolding will include engineered drawings for its erection.

Demolition and disposal of the wall including returns and rubble fill.

Installation of new brick to match existing and laid to original contours with stainless steel
wall ties.

Installation of a compressible seal around penetrations to allow for differential movement
between the steel and masonry.
We estimate the cost of the above work, to be $45,000.
Report Prepared By:
Report Reviewed By:
Steven Gray
Anne Floros, P.Eng.
Page 35
Project No. T070612
November 9, 2007
Table 1 - Cost Summary Table
Base Recommendations
Budget Cost
2009
2008
1. Replace Sloped Roofs with Cool Metal Roofing System
2. Replace Skylights
$
350,000
$
115,000
3. Install Roof Vents with Motorized Fans for Natural Ventilation
$
$
15,000
7,500
4. Solar Power Feasibility Study
5. Replace Main Boiler with Integrated Boiler Plant
6. Ventilation Upgrades - Church
$
72,000
$
15,000
7. Ventilation Upgrades - Parish
$
$
85,000
25,000
$
255,000
8. Lighting Upgrades
9. Replace Church Flat Roofs with Cool Roof System
10. Replace Parish Centre Flat Roofs with Cool Roof System
$
325,000
$
$
$
452,000 $
10,000
45,000
380,000
$
2009
94,000
11. Repair Parish Centre Precast Beams
12. Repair Masonry Cross Structure
Annual Total
Upgrade Options (in addition to above budge costs)
9. Install Green Roof System on Church Roofs (where possible)
10. Install Green Roof System on Parish Centre Roofs (where possible)
11. Install Solar Power System
Annual Total
$
487,500
2008
$
-
2010
$
2010
$
$
94,000 $
200,000
115,000
315,000
Appendix A
Roof Key Plan
Appendix B
Building Energy Audit
Halcrow Yolles
Queen’s Quay Terminal
207 Queens Quay West, Suite 550
PO Box 132, Toronto, Ontario, M5J
1A7
P: +1 416 363-8123
F: +1 416 363-0341
www.halcrowyolles.com

General Report

Transcription

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