Concrete floor installation in Novato CA - a slab that sits on solid, packed ground

A concrete slab in the Bay Area usually costs about $8 to $16 a square foot, before any staining or stamping. A slab with rebar, steel bars that hold it together, costs more per foot than a plain pad. Bay Area home floors usually run four to six inches thick, so check that bids name the same thickness.

Some fine cracking, yes, because a completely crack-free floor isn't realistic even with good design and careful building. Wire mesh won't stop cracks, but placed at the right height it keeps them narrow. Wide cracks and sinking usually trace back to soft ground, so we dig out soft spots and pack the base before we pour.

A vapor retarder, a sheet that slows moisture coming up, protects flooring and coatings best when it sits right against the slab. Placed there, though, it makes cracking much more likely, especially with wetter concrete. So it comes down to what's going on top, and we go over both sides with you before the pour.

A new slab should take foot traffic within 48 hours, while heavier loads may need to wait a week and full curing takes a month. Curing is the slab gaining strength, so ask who'll start it right away with a sprayed compound or damp burlap and keep the floor moist for at least three days.

Check with the City of Novato, which offers permit research online or by appointment at 415.899.8989. Ask too whether your lot is in a state seismic hazard zone, where the hazard may need study during permitting. If you need a permit, we find out which office handles it, do the paperwork and put in writing who's pulling it.

The Contractors State License Board licenses home improvement contractors in California, and concrete contractor is the trade it sets aside for pouring and finishing flat concrete work. State law also puts special requirements on home improvement contracts, meant to head off as many owner and contractor problems as possible.