In our Hawaii building code, there must be no "cinders" under the concrete foundation - this is in effect whether you are on post and pier or slab on grade. Cinders will continue to compact as time goes on. This will affect the stability of your home. Use base course or 3/4"- to dress the house pad. Compact it with a plate compactor. A plate compactor looks like a lawn mower with a flat plate on the bottom. You can rent one for under $75.
If you are doing a slab on grade, try to get the house pad to within 1"+/- of level. This will save you quite a bit on labor and concrete. Do not think you can "eyeball" it. Use a transit. Grade can be very deceiving.
If you are on post and pier, your foundation will consist of shear wall corner footings and possibly 24" x 24" footings or pier block footings. If you are on slab, your foottings will be incorporated into the slab - they will be 16" x 18" and 4" of slab. Rebar is cheap insurance on a slab. It keeps moving in one peice if we have an earthquake. Also use a PSI of 3000 of more helps keep the footings secure. This is not a place to skimp.
No comments:
Post a Comment