Denver Concrete Foundations

Denver didn't get built all at once, and you can read that history in the concrete. A Washington Park bungalow may be riding on a hand laid stone perimeter somebody set about a century ago. A Park Hill four square might have thin poured walls with no steel in them anywhere. Berkeley has both, plus a scrape off going up next door on a lot the same fifty feet wide.

We pour new foundations across all of it. Replacements under standing houses, addition footings that have to behave like the hundred year old work they bolt to, and full basements for infill builds where the excavator barely fits between fences. Our structural engineer is on our payroll, so whoever sets footing width and steel schedule is the outfit that has to build it.

What each generation of Denver house left in the ground

The oldest houses in the city sit on mass, not on engineering. Stone or brick perimeter walls, no reinforcing, a shallow footing, and drainage that consists of hope. Between the wars, poured walls showed up. Better in principle, still unreinforced, still with no drain at the footing. Postwar ranches brought block stem walls over narrow footings. Then a long stretch of nothing, and now infill: engineered walls, drain tile, damproofing, radon sleeve, a stamped set for the whole package.

That spread matters because most of our work in the old neighborhoods isn't a tidy new build on empty dirt. It's surgery. Shoring a standing house while we replace a wall in bays. Park Hill and Washington Park send that job constantly. Central Park sends the clean version, with drawings.

Foundation systems by build era

What goes in the hole before any truck backs up

• Bearing surface checked against the soils report, not against how the dirt looks that morning
• Footings cut below frost depth and stepped where the grade forces a step
• Void form under grade beams when the soils engineer wants somewhere for heaving ground to go
• Steel tied and chaired to the drawing, laps measured instead of eyeballed
• Forms braced hard, because a blowout on a narrow city lot ruins more than the pour
• Anchor bolts and hold downs set while the concrete is wet, never drilled in later as a patch
• Damproofing, drainage board, and perforated drain in washed rock before a single bucket of backfill

Fifty foot lots, big machines, and the neighbor eight feet away

Access decides more about an infill foundation than anything printed on the drawing. On a standard old Denver lot the machine has one way in, the spoil pile has nowhere to sit, and the property line sits close enough that the neighbor's garage joins the discussion. So we plan the dig as a logistics problem first. Where trucks stage. Where dirt goes. Which day the block gets tight.

Shoring is the line item nobody budgets and half these jobs need. Cutting to full basement depth beside a standing structure means that sidewall has to be held, by benching it back where there's room or shoring it where there isn't. You'll hear that from us in week one, in writing.

The pour calendar in a city that freezes every night and thaws by noon

Foundation work runs later into the year than flatwork does. A wall down in a trench is protected on both faces, and the mass carries its own heat while it sets. We place walls into November and December most years with heated mix water, non chloride accelerator, and blankets over the forms.

What stops us is frozen bearing. A footing set on frost is set on something that won't be there in March. And Denver's real trouble isn't deep cold anyway. It's the swing. Forty five and sunny at two, nineteen before dawn, over and over. That cycle punishes fresh concrete and it punishes an open excavation. Break ground in spring if you can. If you can't, say so early and the cold weather plan goes in the bid.