HomeMy WebLinkAboutFOUNDATIONS - 04-00289 - 450 W Main - GarageR403.2 - TABLE R403.3
R403.2 Footings for wood foundations. Footings for wood
foundations shall be in accordance with Figures R403.1(2) and
R403.1(3). Gravel shall be washed and well graded. The maxi-
mum size stone shall not exceed 3/4 inch (19.1 mm). Gravel
shall be free from organic, clayey or silty soils. Sand shall be
coarse, not smaller than 1/16 -inch (1.6 mm) grains and shall be
free from organic, clayey or silty soils. Crushed stone shall
have a maximum size of 1/2 inch (12.7 mm).
R403.3 Frost protected shallow foundations. For buildings
where the monthly mean temperature of the building is main-
tained at a minimum of 64'F (IVC), footings are not required
to extend below the frost line when protected from frost by in-
sulation in accordance with Figure R403.3(1) and Table
R403.3.
Exceptions:
1. No foundation not so protected may be attached to
frost -protected shallow foundations.
2. Unheated garages, porches, utility rooms and:carports
shall not be permitted to be attached to dwelling units
with frost -protected shallow foundation.
FOUNDATIONS
Materials used below grade for the purpose of insulating
footings against frost shall be labeled as complying with
ASTM C 578.
R403.3.1 Protection of horizontal insulation below
gound. Horizontal insulation placed less than 12 inches
(305 mm) below the ground surface or that portion of hori-
zontal insulation extending outward more than 24 inches
(610 mm) from the foundation edge shall be protected
against damage by use of a concrete slab or asphalt paving on
the ground surface directly above the insulation or by ce-
mentitious board, plywood rated for below -ground use, or
other approved materials placed below ground, directly
above the top surface of the insulation.
R403.3.2 Drainage. Final grade shall be sloped in accor-
dance with Section R401.3. In other than Group I Soils, as
detailed in Table R405.1, gravel or crushed stone beneath
horizontal insulation below ground shall drain to daylight or
into an approved sewer system.
R403.3.3 Termite damage. The use of foam plastic in areas
of "very heavy" termite infestation probability shall be in
accordance with Section R324.4.
TABLE R403.3
MINIMUM HJRIH ATION REQUIREMENTS FOR FROST -PROTECTED FOOTINGS IN HEATED BUILDINGSa
AIR FREEZING INDEX
(OF-days)b
VERTICAL INSULATIONR-VALUEo•e
R.VALUEc,d
HORIZONTAL INSULATION
Along walls At corners
HORIZONTAL INSULATION DIMENSIONS
PER FIGURE R403.3(1) (Inches)
A B C
1,500 or less
4.5
NR NR
NR
NR
NR
2,000
5.6
NR NR
NR
NR
NR
2,500
6.7
1.7 4.9
12
24
40>cm,
3,000
7.8
6.5 8.6
12
24
40
3,500
9.0
8.0 11.2
24
30
60
40000
10.1
10.5 13.1
24
36
60
For SI: I inch= 25.4 mm, oC = [(oF)-32]/1.8.
a. Insulation requirements are forprotectionagainst frost damage in heated buildings. Greatervaluesmay, be required to meet energy conservation standards. Inter-
polation between values is permissible.
b. See Figure R403.3(2) for Air Freezing Index values.
c. Insulationmaterials shall provide thestated minimmR-values underlong-termexposure to moist, below -ground conditions in freezing climates. The following
R -values shall be used to determine insulation thicknesses required forthis application: Type 11 expandedpolystyrene-2ARperinch;Type lVextrudedpolysty-
rene--4.5R per inch; Type VI extruded polystyrene -4.5R per inch; Type IX expanded polystyrene -3.2R per inch; Type Xextmded polystyrene -4.5R per
inch. NR denotes "not required."
d. Vertical insulation shall be expanded polystyrene insulation or extruded polystyrene insulation.
e. Horizontal insulation shall be extruded polystyrene insulation.
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2000 INTERNATIONAL RESIDENTIAL CODE
FOUNDATIONS
INSULATION DETAIL
FLASHING PER SECTION R703.8
INSULATION PROTECTION PER SECTION R403.3.
SLOPE FINAL GRADE PER SECTION R403.3.2�
121N. MIN.
i
NOMINAL 4IN. SCREENED AND'
WASHED GRAVEL OR CRUSHED
STONE, DRAINED PER SECTION
R403.3.2
HORIZONTAL INSULATION PLAN
For SI: I inch = 25.4 mm.
IN. MAX.
00 -1 a
sI o - o�
FIGURE R403.3(t)
SLAB -ON -GROUND FOUNDATION FLOOR
PER SECTIONS R403.1 AND R506
VERTICAL WALL INSULATIONa
40RIZONTAL INSULATIONa
a. See Table R403.3 for required dimensions and R -values for vertical and horizontal insulation.
I
FIGURE R403.3(1)
INSULATION PLACEMENT FOR FROST -PROTECTED FOOTINGS IN HEATED BUILDINGS
2000 INTERNATIONAL RESIDENTIAL CODE
65