Temporary
Services | Surveying
and Layout | Excavation
| Footings/Foundation
| Foundation
Options | Subrough
Plumbing & HVAC | >>Dampproofing,
Waterproofing and Window Wells | Water
and Sewer Laterals | Foundation
Drain, Backfill and Rough Grade |
Basement Slab
Once the forms
are stripped from the foundation, the window wells
and waterproofing can be started. It is usually a
good idea to let the walls set a day or two to ensure
that they are cured sufficiently.
The window wells
are attached to the foundation wall with concrete
anchors. The height of the window well is set 4-6
inches above final grade. The projection (the depth
of the well from outside edge to foundation) of the
well is determined by code. For bedroom wells the
projection must be 3' which allows for easy egress.
For all other rooms, the projection is 2'. The bottom
of the window well should also extend a minimum of
6' inches below the bottom of the window. After backfilling
gravel (4"-6") is placed in the bottom of
the window well to facilitate draining. Care should
be taken not to backfill too much dirt against the
window well or they will bend and deform.
It is quite common,
especially in older homes or where water tables are
high, for subterranean water to find it's way into
basements. Dampproofing is the process of spraying
a water resistant substance (usually black tar) on
the foundation wall to repel water. It does not guarantee
that water won't get in, so many contractors recommend
waterproofing on new foundations.
Waterproofing is the process of placing a rubber membrane
or spraying a rubber coating on the foundation walls.
Even if the foundation develops hairline cracks, the
rubber coating is flexible and will stretch with the
crack. The contractor usually guarantees the coating
for a certain length of time. Although it is more
expensive, many contractors are waterproofing new
foundations. It is well worth the extra expense especially
where subterranean water exists.
Before scheduling dampproofing or waterproofing, the
contractor uses paint to mark the height and areas
to be sprayed for the installers. For existing basements
there are now new leak stop systems that can be applied
from the inside of the house. These systems just fix
the areas that are known to leak.
Under crawlspace
and slab foundations, vapor barriers are placed on
the ground to prevent moisture from the earth from
rising into the structure. A thin (6mil) plastic is
placed on the ground often before the post and beams
are installed. A barrier can be placed after the house
is framed but it is a lot more time consuming at this
stage.
Vapor barriers are placed
under slabs to prevent moisture from rising into the
slab floor. A thicker plastic is recommended because
of possible punctures during the slab pour.
Dampproofing is a
popular job for the owner builder to perform. Even
though professionals use a spray gun to apply dampproofing
tar, paint rollers work fine.
Installing window wells is usually a two man job but
is not too difficult for the owner builder. A hammer
drill and a concrete drill bit are the only specialty
tools needed.
Vapor barriers can also be installed by the owner
builder. Where
seams meet the vapor barrier should be overlapped
about 12" and taped with a waterproof tape.
