 Limited
Visual Inspection:
Lot
Grading & Drainage:
"We Inspect 'You' Decide!"
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The
International Residential Building Code
is very specific about lot
drainage. Unfortunately,
it does not apply to slab on grade
foundations. Slab on grade
foundations are the most common
type of foundations in the gulf
coast area. |
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What does the International
Residential Code say?
(See below) |
§RR401.3 Drainage.
Surface drainage shall be
diverted to a storm sewer
conveyance or other approved
point of collection so as to not
create a hazard. Lots shall be
graded so as to drain surface
water away from foundation
walls. The grade away from
foundation walls shall fall a
minimum of 6 inches (152 mm)
within the first 10 feet (3048
mm).
EXCEPTION: Where lot
lines, walls, slopes or other
physical barriers prohibit 6
inches (152 mm) of fall within
10 feet (3048 mm), drains or
swales shall be provided to
ensure drainage away from the
structure. |
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The key words to
§RR401.3 Drainage, is
foundation walls ; slab on
grade foundations do not have
foundation walls. |
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(Example #1) This is the most
common type of drainage. |
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(Example #2) |
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we want to see when we inspect
grading and drainage is positive
drainage away from the
foundation and
off the lot. The grading
should slope away from the foundation.
The grade away from foundation
should fall a minimum of 6
inches within the first 10' feet.
While maintaining a
minimum of four (4") inches
of foundation grade beam exposure
where brick is installed and six
(6") where sidings
are installed.
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The purpose of this type of
drainage is to protect your
foundation from possible
differential movement. Ponding water and/or
saturated soils is detrimental
to the performance of your
foundation. Water should not
pond with in 10' feet of your
foundation longer than 24 hours
and 48 hours in the swells of
the yard. |
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Below are photo examples of bad
drainage. If your builder is not
installing sod in your side
yards or in the back yards, make sure
you take photos (with date
stamps) of how the builder
graded your yard. Builders will
always claim that you were the
one that changed the
grading if you have foundation
problems; or if there is (any) ponding water. After
all, the city inspectors passed the
grading. |
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(click pics to enlarge) |
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The best remedy
to protect your foundation is preventive conditions
which include proper grading; and
proper drainage away from
the foundation and off the lot!
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 Related
Information: |
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