Structural Fill and Compaction

Structural Fill and Compaction in Coeur d’Alene

When a pad, footing, or slab has to carry load, ordinary fill dirt is not enough. Kumanomoto places engineered structural fill in controlled lifts and compacts it to a specified density, building the stable, load-bearing subgrade a foundation needs. We do this work across Coeur d’Alene and out toward Hayden, matching material and method to what the plan calls for.

Why Compaction Matters

Loose soil holds voids, and voids let a slab settle and crack over the first few winters. Compacting to about 95 percent of maximum dry density, measured by a standard Proctor test (ASTM D698), squeezes those voids out so the fill behaves like solid ground. On North Idaho sites that freeze and thaw, a properly compacted pad is the difference between a floor that stays flat and one that heaves off Kathleen Avenue.

Our Process

We spread imported fill in shallow layers, usually six to eight inches, and compact each layer with a plate compactor, jumping-jack rammer, or sheepsfoot roller before the next lift goes down. Where the plan requires it, a nuclear density gauge confirms we hit the target before we build higher. Backfill around foundations gets the same lift by lift treatment so it does not settle later.

Call (986) 867-4576 for a free estimate on structural fill and compaction in Coeur d’Alene.