Centennial Concrete Foundations

Almost nobody in Centennial is building a foundation on empty ground. The subdivisions filled in a long time ago, so what we get called for is an addition off the back of a ranch, a detached garage where a shed used to sit, or a basement wall that has to come out and go back in under a house full of furniture. That changes the arithmetic on a bid in ways that catch people off guard.

So this page is about where the money goes. No figures, because a foundation quoted before somebody stands on your property is a guess wearing a suit. What we can do is lay out the conditions that separate a straightforward pour from an expensive one, and tell you which ones you can change.

Soil bearing is the first number, and it isn't ours to pick

Before anybody prices anything, we need to know what your dirt will hold. On an addition or a garage that usually means a couple of test holes and a letter from a soils engineer rather than a full drilling program, but it means something. The figure that comes back is an allowable bearing pressure, and every footing dimension on the drawing runs off that one number. Weak soil, wide footings. Strong soil, narrow ones.

What we watch for around this part of Arapahoe County isn't weakness so much as ground that changes volume. Weakness you answer with area. Movement you answer with depth, plus a way to let the soil rise without carrying the building along. That means drilled piers set below the zone where moisture swings, a grade beam spanning pier to pier, and void form under the beam so the dirt has somewhere to go. We've found both conditions inside one Foxridge block, which is why we won't price your foundation off a neighbor's job.

Bare lot against a house that's already there

The line items people try to delete first

Every foundation bid has a soft middle and homeowners find it fast. Void form looks like cardboard. A perimeter drain looks like pipe in a ditch. Damproofing looks like paint. All three are small next to the concrete, all three vanish within a week, and all three decide whether we ever come back.

Void form is the clearest example. It sits under the grade beam so the beam bridges from pier to pier instead of resting on soil that wants to rise. Take it out and you've bought an expensive foundation the ground can pick up and carry. Same answer on the footing drain: if there's finished space behind that wall, it goes in, bedded in washed rock, wrapped, sloped, with an outlet a person can still find a decade later. Where we're glad to shrink a number is scope you don't need. Not every addition wants a basement under it, and if spread footings work on your ground we say so.

What lands in our estimate whether you ask for it or not

• Test holes and an engineer's letter, or a review of soils work you already have
• Overexcavation and replacement wherever the hole comes up soft at the bottom
• Shoring anywhere we work under something that has to stay standing
• Steel tied to the stamped drawing, on chairs, cover checked before the inspector arrives
• Void form under grade beams, sized to the movement the engineer expects
• Perimeter drain in washed rock with filter fabric and an outlet that has real fall
• Backfill placed in lifts, and a return trip to top off the trench once it settles

Digging season here, and the month that quietly adds cost

Our season runs long. We pour foundation concrete through the winter using heated mix water, non-chloride accelerators, and blankets over everything, and it cures out fine. What cold charges you for is the ground, not the mix. Frozen soil breaks up slowly, an excavator burns hours it wouldn't burn in September, and we won't set a footing on frozen ground no matter what the schedule wants.

Late summer into fall is the comfortable window. Trench walls stand up, backfill compacts the way the spec assumes, and there's warm weather left to shape finish grade before snow. Spring is the stretch we steer people out of. Melt at 5,833 feet keeps feeding saturated clay into May, and an open trench beside a Homestead ranch in April slumps a little more every time the sky opens up.