Foundation installation in Walnut Creek CA - the right base for your lot and budget

It mostly comes down to your lot, your budget and your soil. On flat ground a slab is the economical, quick choice, and one engineering firm notes that post-tensioned slabs, which use tightened steel cables inside, usually need less labor and formwork than a deep raised foundation. On a slope, a raised foundation can follow the ground without big retaining walls or hauling dirt away, and if the top 5 to 10 feet of soil is especially unstable, the same firm says deep piers that hold the building off that soil are often the safest long-term choice.

Foundation installation in the San Francisco area usually runs about $6,500 to $35,000 for a whole project. Where yours lands depends on the size of the building, slab or raised, how steep the lot is and how much dirt has to move. I'll put a price for your lot in writing after I walk it.

Yes, adding a structure takes a building permit from the city, and a big cut or deep fill adds the grading permit described above. We check which ones apply during the estimate so the paperwork doesn't hold up the dig.

A contractor licensed for concrete work can, and the state licensing board's C-8 concrete contractor classification covers forming, pouring, placing and finishing concrete. A B general building contractor can take the main contract if it holds that classification or hires a properly licensed specialty contractor for the concrete. A homeowner improving their own home can skip the license only when every one of the state's conditions holds, including finishing the work before any sale, living there 12 months before it's done and building no more than two structures in three years.

After the wet season, if you can, is what engineering guidance on expansive soils recommends, along with drainage that carries off any water that ponds. The same guidance calls for keeping open excavations from drying out, so it's fair to ask any crew how they'll protect the trenches. We can plan your start date around the wet season.

Keep the ground around the building sloping away from it, about 5 percent according to the same expansive soils guidance, so water runs off instead of sitting against the foundation. Check it again after landscaping or a hard rain, since a new flower bed or a settled trench can tip the ground back toward the house.