Installation guide

32
Appendix I
For installations regulated by the International Residential Code, the
support foundation for the fireplace installed on concrete
shall
consist
of
a m
inimum
of 6 inche
s thick reinforced concrete slab. The minimum specified compressive strength of
f’
c
, shall be as
required in Table R402.2 of the International Residential Code (IRC). Concrete subject to moderate or severe weathering as indi
cated
in Figure R301.2(3) of the International Residential Code (IRC) shall be air entrained
as specified
in Table R402.
2 of the International
Residential Code (IRC). The maxi
mum weight of fly ash, other pozzolans, silica fume, slag or blended cements that is included in
concrete
mixtures for garage floor slabs and for exterior porch
es
, carport slabs and steps that will
be exposed to deicin
g chemicals
shall not exceed the percentages of the total weight of cementitious
materials specified in Section 4.2.3 of ACI 318. Materials
used to
produce concrete
and testing thereof shall comply with the applicable standards listed in Chapter 3 of ACI 318.
For installations regulated by the International Building Code (IBC), the support foundation for the fireplace installed on concrete
shall consist of a minimum of 6 inches thick reinforced concrete
slab. The concrete
strength and durability shall comply with S
ections
1903, 1904 and 1905 of the Internat
ional Building Code (IBC)
.
TABLE R402.2 MINIMUM SPECIFIED COMP
RESSIVE STRENGTH OF CONCRETE
MINIMUM SPECIFIED COMPRESSIVE STRENGTH
a
(f’
c
)
Weathering Potential
b
TYPE OR LOCATION OF CONCRETE CONSTRUCTION
Negligible Moderate
Severe
Basement walls, foundations and other concrete not exposed
to
the weather 2,500 2,500 2,500
c
Basement slabs and interior slabs on grade,
except garage floor slabs
2,500 2,500 2,500
c
Basement walls, foundation walls, exterior walls and other vertical concrete
work exposed to the weather
2,500 3,000
d
3,000
d
Porches, carport slabs and steps exposed to the weather, and
garage floor slabs 2,500 3,000
d,e,f
3,500
d,e,f
a. Strengt
h a
t 2
8 days p
si.
b. See Figur
e R
301.2(3)
fo
r w
eathering potential.
c.
Concrete in these locations that may be
subject to freezing and thawing during construction shall be air-entrained concrete in
accordance with Footnote d.
d. Concrete shall be air-entrained. Total air
conten
t (
percent by volu
me of concrete) shall be not less than 5 percent or
more than
7 percent.
e. See Section R402.2 for maximum cementitious materials content.
f. For garage floors w
ith
a steel troweled finish, reduction of the total air content (percent by volume of concrete) to not less than
3 percen
t i
s permitted if the specified compressive strength of the concrete is increased to not less than 4,000 psi.