Soils & Foundations
Common Foundation Designs
Refer again to the illustration above and ask yourself the question... "Is it possible to safely build on highly expansive soils, and avoid the associated problems?"
Yes. There are construction techniques to help solve the problem. However, it is essential that you start with a properly designed and constructed foundation. The illustration below shows several details to help control the wetting of foundation soils and some construction details to minimize any damage should some wetting and/or swelling occur.
A. Walls have been properly voided using appropriate carton forms (WallVoid® System)
B. Slabs have been properly voided using appropriate carton forms (SlabVoid® System)
C. The land slopes away from the foundation. Extra soil has been added to compensate for settlement of backfilled soils. Trash, construction debris, frozen soil, etc., has been kept out of backfill.
D. A foundation drain has been installed - to remove any water that might reach the basement level.
E. Shrubbery requiring low moisture is located away from the house and is hand watered as needed.
F. Downspouts discharge above ground and have extensions fixed in place to take rain water away from the house. Gravel beds installed around foundation are underlain with nonporous polyethylene. Gravel is restrained with perforated edging to allow water to flow away from foundation.
G. Interior columns have been fitted with adjustable screw jacks to allow for correction of some pier movement.
H. A mat of reinforcing steel has been added in exterior basement walls to resist lateral loads.