Single-Family Basement Finish with Fireblocking

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Please read the following information
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City of Thornton Building Inspection Division
9500 Civic Center Drive
Thornton, CO 80229
303-538-7250
buildings@cityofthornton.net
Basement Finish Details
Emergency Escape & Rescue Window Well
Emergency Escape & Rescue Window
City of Thornton Building Inspection Division
9500 Civic Center Drive
Thornton, CO 80229
303-538-7250
buildings@cityofthornton.net
TYPICAL FIREBLOCKING DIAGRAM
Treated Sill
Plate
Floor Joists
Rim Joist
Pack with Insulation or Foam
Top
Plate
Horizontal Fireblock
(Sheetrock or other
fireblocking material)
Vertical Fireblock
2012 International Residential Code
R302.11 Fireblocking. In combustible construction,
R602.8 shall
Fireblocking
required.
Firefireblocking
be provided to
cut off all concealed
blocking
provided
to cut off
draft
openingsshall
(bothbe
vertical
and horizontal)
andall
to
concealed
draft openings (both vertical and
form
an effective
firehorizontal)
barrier between
and an
between
a top fire
story
and stories,
to form
effective
andbarrier
the roofbetween
space. stories, and between a top
story and the roof space.
Studs
Foundation Wall
Treated Plate
Concrete Floor
Floating Wall System May
Be Required
Fireblocking
Fireblocking
be provided in
shall beshallprovided
in wood-frame
wood-frame
construction
in
the
following
locations:
construction in the following locations.
1. In
spaces of
stud walls
andwalls
partitions,
1. concealed
In concealed
spaces
of stud
and
includingpartitions,
furred spaces
and
parallel
rows
of studs
including furred spaces
andor
staggered
studs,
as
follows:
parallel rows of studs or staggered
1.1. Vertically at the ceiling and floor levels.
studs; as follows:
1.2. Horizontally at intervals not exceeding 10 feet
1.1. Vertically at the ceiling and floor
(3048 mm).
levels.
2. At all interconnections between concealed vertical
1.2.
Horizontally
intervals
not
and horizontal spaces suchat
as occur
at soffits, drop
exceeding
10
feet
(3048
mm).
ceilings and cove ceilings.
2. concealed
At allspaces
interconnections
between
3. In
between stair stringers
at the
concealed
andspaces
horizontal
top and bottom
of the vertical
run. Enclosed
under
spaces
such
occur R302.7.
at soffits, drop
stairs shall
comply
withasSection
ceilings
and cove
4. At openings
around
vents,ceilings.
pipes, ducts, cables and
3. at In
concealed
between
stair
wires
ceiling
and floor spaces
level, with
an approved
materialstringers
to resist the
flame and
at free
the passage
top andofbottom
of the
productsrun.
of combustion.
Enclosed spaces under stairs
The material
filling
thiswith
annular
spaceR311.2.2.
shall not be
shall comply
Section
required
to
meet
the
ASTM
E
136
requirements.
4. At openings around vents, pipes, and
5. For the
fireblocking
of chimneys
fireplaces,
ducts
at ceiling
and floorandlevel,
with
see Section
R1003.19.
an approved material to resist the free
6. Fireblocking
of aand
two-family
dwelling
passageof cornices
of flame
products
of
is required
at
the
line
of
dwelling
unit
separation.
combustion.
5.
For the fireblocking of chimneys and
fireplaces, see Section R1001.16.
6. Fireblocking of cornices of a twofamily dwelling is required at the line
See Next Page for Fire Blocking Materials
of dwelling unit separation.
See next page for Fireblocking Materials
Fire Blocking Materials
R302.11.1 Fireblocking materials. Except as provided in Section R302.11, Item 4, fireblocking shall consist of the
R602.8.1 Materials. Except as provided in Section R602.8, Item 4, fireblocking shall consist of 2-inch
following materials.
(51mm)
or two thicknesses of 1-inch (25.4 mm) nominal lumber with broken lap joints, or
1. Two-inchnominal
(51 mm) lumber,
nominal lumber.
one
thickness
of
23/32-inch
wood
structural
panels
joints backed by 23/32-inch (19.8 mm)
2. Two thicknesses of 1-inch (25.4(19.8
mm) mm)
nominal
lumber
with broken
lapwith
joints.
wood
structural
panels
or
one
thickness
of
3/4-inch
(19.1
mm)
particleboard
joints backed by 3/4-inch
3. One thickness of 23/32-inch (18.3 mm) wood structural panels with joints backed by 23/with
32-inch (18.3 mm) wood structural
(19.1 mm) particleboard, 1/2-inch (12.7 mm) gypsum board, or 1/4-inch (6.4 mm) cement-based millboard.
panels.
Battsthickness
or blankets
mineral
wool or glass fiber
otherbacked
approved
in such a manner as to
4. One
of 3/4of
-inch
(19.1mm)particleboard
withorjoints
by 3/4materials
-inch (19.1installed
mm) particleboard.
be securely retained
in gypsum
place shall
be permitted as an acceptable fire block. Batts or blankets of mineral or
5. One-half-inch
(12.7 mm)
board.
glass fiber or other
approved
non-rigid
materials shall be permitted for compliance with the 10 foot
6. One-quarter-inch
(6.4 mm)
cement-based
millboard.
horizontal
fireblocking
walls
constructed
usingapproved
parallelmaterials
rows ofinstalled
studs in
or such
staggered
studs.
Loose-fill
7. Batts
or blankets
of mineralinwool
or glass
fiber or other
a manner
as to be
securely
retained
in place.
insulation
material shall not be used as a fireblock unless specifically tested in the form and manner
8. Cellulose
as tested
for the specific
application.
intended insulation
for use toinstalled
demonstrate
its ability
to remain
in place and to retard the spread of fire and hot gases.
R302.11.1.1
Batts
or blankets
of mineral
or glass
fiber. Batts
or insulation
blankets ofused
mineral
or glass fiber or
other
R602.8.1.1
Unfaced
fiberglass.
Unfaced
fiberglass
batt
as fireblocking
shall
fillapproved
the entire
nonrigid
materials
shall
be
permitted
for
compliance
with
the
10-foot
(3048
mm)
horizontal
fireblocking
in
walls When
cross section of the wall cavity to a minimum height of 16 inches (406 mm) measured vertically.
constructed
using parallel
rows of
studs or staggered
studs.
piping, conduit
or similar
obstructions
are encountered,
the insulation shall be packed tightly around the
obstruction.
R302.11.1.2 Unfaced fiberglass. Unfaced fiberglass batt insulation used as fireblocking shall fill the entire cross section
of the wall cavity to a minimum height of 16 inches (406 mm) measured vertically. When piping, conduit or similar
R602.8.1.2 Fireblocking integrity. The integrity of all fireblocks shall be maintained.
obstructions are encountered, the insulation shall be packed tightly around the obstruction.
R302.11.1.3 Loose-fill insulation material. Loose-fill insulation material shall not be used as a fireblock unless
specifically tested in the form and manner intended for use to demonstrate its ability to remain in place and to retard the
spread of fire and hot gases.
R302.11.2 Fireblocking integrity. The integrity of all fireblocks shall be maintained.
ThurstonThurston
County Resource
StewardshipServices
Department
County Development
2000
Lakeridge
Dr SW;
Olympia,
WAWA
98502
2000
Lakeridge
Dr SW;
Olympia,
98502
Phone:
(360)
786-5490;
TDD:
(360)
754-2933
Phone: (360) 786-5490; TDD: (360) 754-2933
FAXFAX
(360)
754-2939
(360)
754-2939
Website:
www.co.thurston.wa.us/permitting
Website:
www.co.thurston.wa.us/permitting
TC Figure 12 Stair / Handrail
7/1/06
3-2013