Low foundation blues
user-6610113
| Posted in General Questions on
I’m renovating a 100 year old home in southern California (zip 92870). The home has a crawlspace and the floor joists/sill plate sit on top of the stem wall. My problem is that the level of the ground is at to 1″ above the sill plate. The house is stucco clad. There was no weep screed placed, rather the stucco was continued down over the stem wall.
To top it all off we have moderately expansive soil for which I will be putting in perimeter drains.
Do you have any detailing advice that would allow me to keep the ground level at the base of the house where it is (or 1-2 inches below the sill plate)?
GBA Detail Library
A collection of one thousand construction details organized by climate and house part
Search and download construction details
Replies
Matt,
The solution is to jack up the house and raise the foundation.
I had stucco nearly down to ground level in SoCal. I recall code requiring a 1" gap between the bottom of the stucco and the ground. We dug down and created a drainage swale down the side of the house away from the foundation and backfilled with landscape cloth and ~4" of washed 3/4" gravel to 1" below the stucco. I think the gap is pretty important, not only for water weeping up the stucco, but also keeping an eye out for termites and laying down a perimeter insecticide barrier for the ever-present Argentinian ants.
If you install hardscaping you can have the sill plate 2 inches to that (concrete, pavers ets.) If it is sill plate to dirt then the code is 6 to 8". Perhaps installation of one or two rows of pavers, 6 to 12" of hardscape, could get allow you to meet the code required distance. See section CA Residential Code R317.1 for sill to ground code section. The Pavers would be good cover for your drain rock to keep it from getting filled or covered with dirt & plants.
It may be good to score the stucco, down near or in the new gravel drain ,with a grinder to give a path way for the water to leave the stucco. 1/4" x 1/4" groove