Slab foundation building in El Monte, CA - a floor built for the soil under it

Most people who call us are planning a new home or an addition, or they're replacing a slab that's given out. The price and the schedule are mostly set by things you can't see: what the soils report finds, how much ground has to come out and be replaced, whether you go with a standard or a post-tensioned slab, and how big the footprint is. The calendar usually turns on the reports, the plans and the city's review more than on the pour, and your written estimate spells out what's in the price and what isn't.

I start with the soils report and the engineer's plans, because they tell us how deep to dig, what goes under the slab and how much steel goes in it. Our crew digs out to firm ground and packs the subgrade, the dirt the slab sits on, in layers instead of raking it level, because a base that's only raked settles with the dirt. We set the forms and the rebar, the steel that holds the slab together when the ground pulls at it, check where the water will run so nothing falls toward the house, and pour early so the top doesn't dry out weak in the afternoon heat. On ground that shrinks and swells, I'll lay out a post-tensioned slab next to a standard one so you can weigh them. We plan the control joints, grooves cut into the surface, so if the slab cracks, it cracks where we chose. Then it cures, the wait while it gains strength, before anyone builds on it. Here's the trade-off I'll always name. The base is buried on day one and it's the first thing people want to cut, but I'd spend your money there before the finish, because the floor only stays flat if what's under it does.

Some jobs need more than a slab. If your plans call for a raised floor, stem walls or deep footings, that's our foundation installation work, and I'll tell you which one your lot points to. Small property owners who need a slab for cars can look at our concrete parking lot building, which starts with the same base work.

El Monte has soil that shrinks when it dries and swells when it's wet, and the city requires slabs, and the footings under bearing walls, to be designed for it. The city also wants the plans drawn by an architect or engineer registered in California, unless the work is cosmetic or it's a wood-framed home designed strictly to the code's standard construction rules. On lots inside the state's mapped liquefaction zones, where shaking can turn wet soil soft, the state requires the soil under the foundation to be investigated and fixes built into the design, and cities use those maps when they issue permits. So we build from your engineer's plans, not a rule of thumb, and if your lot needs a report or plans first, we tell you at the start and help you get them.

We're based in El Monte and work the cities around it, and we see the same kind of ground on jobs in Rosemead and South El Monte. A lot of the older slabs we walk around here have cracks that open and close with the seasons, which is why I want to see the soil before I talk about the slab.