HomeMy WebLinkAboutREDLINED PLANS - 00-00020 - 185 E 3rd S - New DuplexFOUNDATION DRAINAGE
Section 405 0£ tl„e ].998 -Iut a;iozial One and Two Family Dwelling Code req~tzres that
drains t~•an be provided aro»ad £ouudations_ T]ie City o£Raxburg Build's DepariR.ezit grid the
City Engineer Dave decided not to enforce this rule.
The building lots located off of the hdl and down in the valley almost all have a soil
structure which cansists of top so~1 over gravel. Section 405 of the Code includes an exception
which excludes well drained soils. The lots on the hill are another matter aIl together. These Lots
are almost entirely comprised of silt over bedrock. Foundation drainage could be very beneficial
for most of these lots. Many houses on the hill have part of their foundations bearing directly on
the bedrock. As water seeps into the soil (especially in springtime] it tends to drain downhill
along the bedrock. Some of the foundations act as a dam and divert the flow of the water azound
them This lends the home to possible waxer damage in the basements.
Foundation drains as called for in the International Code should be installed at properties
which match the descriptions given above. We will allow the contractors and developers to make
this judgement call. Included below is the Code covering this issue.
SECTION 4Q5
FOUNDATION DRAINAGE
405.1 Concrete or masonry foundations. Drains shall be
provided around all concrete or masonry foundations enclosing
habitable or usable spaces located below grade, Drainage tiles,
gravel or crushed stone drains, perforated pipe or other ap-
proved systems or materials shad be installed at or below the
area to be protected and shall discharge by gravity or mechani-
cal means mto an aPProv~ drainage system. Gravel or crushed
stone drains shall extend a minimum of 1 foot (305 mm) beyond
the outside edge of the footing and a minimum of 6 inches (153
mm) above the top of the footing and be covered with an
approved filter membrane material, The top of open joints of
drain tiles shall be protected with strips of building paper, and
the drainage tiles or perforated pipe shall be placed on a
minimum of 2 inches (51 mm) of washed gravel or crushed rock
at least one sieve size larger than the file joint opening or
perforation and covered with a minimum of 6 inches (1S3 aum)
of the same material.
Exception: A drainage system shaIl not be required where
the foundation is installed on well-drained ground or sand-
gravel mixture soils according to the Unified Soil Classifi-
cation System, Group I Soils, as listed in Table 405.1.
405.2 Wood foundations. Wood foundations enclosing habit-
able or usable spaces located below grade shall be adequately
drained in accordance with Sections 405.2.1 through 405.2.3.
1998 !M'EANATiONAL QNE-AND TWO-FAMILY DWELLING CODE