Centennial Stem Wall Contractors

Open the hatch on an older Centennial ranch and there's a good chance the crawl space floor is still dirt. Somebody rolled poly across it once, the corners have curled, and a pale crust runs along the base of the wall where moisture has come and gone for years. None of that is rare. All of it reports on conditions outside that concrete.

Stem wall work is soil and water work with some concrete attached. The wall itself is straightforward. What decides how it lives is the material under the footing, whatever got shoved back into the trench outside, and whether water arriving at the wall has anywhere to go other than through it.

The wall is fine. It's the trench that decides things.

A stem wall footing wants to sit on undisturbed soil or on fill that was placed and compacted on purpose. That part is easy to get right. What goes wrong later happens outside, when an excavator pushes native clay against the wall in one afternoon and calls it backfill. That material never gets the compaction the plan assumed, so it settles for years and forms a trough right where you least want one.

The other failure mode is subtler. Somebody puts clean rock against the wall, packs clay over the top of it, and never gives the rock an outlet. Now the trench is a bathtub with a porous liner, collecting everything the roof and the lawn send it and holding it against your concrete. Rock without a drain is storage. Rock with a drain and an outlet is drainage. That difference is most of this trade.

Where the water is actually coming from

Before anybody digs we go find the source, because the fix changes completely depending on the answer. Roof water is the usual culprit and the cheapest to solve. A downspout emptying two feet from the wall dumps a huge volume into one small patch of soil several times a year, and extending it is an afternoon of work that beats most of what we could sell you.

After that comes irrigation. Beds that get watered daily along the south wall, heads that drifted out of aim years ago, a lawn program running through a wet May. Then window wells with no drain, and grade that fell back toward the house as the old trench settled. Around Willow Creek and Southglenn, where yards have been reworked two or three times, the finish grade rarely resembles what the builder left. So we shoot elevations instead of eyeballing.

Interior drain, exterior drain, or neither

What we look at down there before quoting anything

• How high the staining and mineral crust run up the inside face
• Whether the ground under the poly is damp, wet, or genuinely holding water
• Sill plate and joist ends, checked with a moisture meter rather than a thumb
• Vent locations, and whether anybody has blocked them off over the years
• Any existing sump, and whether the pump and discharge still work
• Exterior grade taken at several points around the full perimeter
• Every downspout outlet, window well, and hose bib along the wall

Two different seasons for two different halves of this work

Interior crawl space work is a winter job and we like it that way. It's out of the weather and our schedule has room. Sealing a floor, running an interior drain, setting a sump, and fixing the vapor situation go as well in January as in July.

Trenching outside is the opposite. That work wants dry ground, so late summer through fall is when we push it. Trench walls hold their shape, backfill compacts the way it's supposed to, and there's still time to shape the finish grade before the first snow. We will pour a new stem wall in cold weather with heated water and blankets, no problem. What we won't do is backfill with frozen clods, because frozen dirt is full of voids that appear the week it thaws.