Hillside Alluvium, Old Fill, and Slabs With No History
Sun Valley sits in a north-trending basin between hills, and the ground is mostly alluvium washed off those slopes — sandy and gravelly with decomposed granite in it, generally decent bearing material and generally cooperative. There are clay lenses in the lower and flatter parts of the valley, and the lower you are the more likely you are to find fine-grained material that needs base import. The real variable here, though, is not the native soil. It is fill.
Because so much grading and building here happened over decades without much documentation, a lot of Sun Valley lots carry fill nobody can account for. Pads pushed up to level a manufactured home, trenches backfilled by hand, old driveways buried instead of removed, and in a few cases genuine debris fill. Fill that was never compacted in lifts keeps consolidating, and a slab poured over it settles unevenly. That is the main reason we dig test holes before quoting anything larger than a small pad here, and the main reason a Sun Valley estimate sometimes carries a range on the dirt work rather than a single number. We would rather show you the hole than guess.
Steeper lots on the east and west edges bring their own set of issues. Water coming off a slope has to be managed before you put concrete in its path, and a driveway on a grade needs its cross-slope and its transitions worked out so vehicles do not scrape and water does not run to the garage door. Thickened edges and keyed footings matter more on sloping ground, and a retaining element is sometimes part of the concrete job whether anyone wanted it to be.
Then there is the fact that a good deal of the existing concrete here went in without air entrainment. At about 4,600 feet under clear skies, Sun Valley runs through freeze-thaw cycles on most winter nights — the surface freezes after sundown and thaws in the sun the next day, over and over. Concrete without an entrained air system gives that expanding water nowhere to go, and the result is scaling: the top layer flaking away in sheets. Once scaling is well established it is not repairable in any lasting way. Resurfacing can buy time and look decent, and we will do it and tell you honestly how long it is likely to last, but a scaled slab is on a clock.
What we pour in Sun Valley
- Driveways, replacements, and widening strips
- Patios, walkways, and outdoor living slabs
- Front steps, stoops, and porch slabs on proper footings
- Garage, shop, and outbuilding floors
- RV, boat, shed, and equipment pads
- Repair, resurfacing, slab lifting, and removal
