
OAC Construction
demolition, driveways, erosion control, excavation, foundations, grading

Foundations in Washington
Footings, stem walls, slabs, piers and basement walls formed and poured to the plans and inspected before backfill.
Project guide
Foundation contractors build the part of the structure that carries everything above it into the ground: spread footings below frost depth, stem walls or basement walls, monolithic and slab-on-grade foundations, and pier or grade beam systems where soils are poor. The work follows the stamped plans and the geotechnical report, and it is inspected at fixed points, usually the open footing trench with rebar in place before the pour, then again before the slab and before backfill. Frost depth sets the footing bottom, from about twelve inches in the Gulf states to four feet or more across the northern tier. Waterproofing or dampproofing, a footing drain and free-draining backfill are what keep a basement dry, and they are cheapest to do right while the wall is still exposed.
GradeLine lists 153 foundations contractors that serve Washington.Compare their work and equipment, then confirm availability and service area before requesting a quote.
Listed businesses are based in Ridgefield, Spokane, Edgewood, Snohomish, Longbranch, Hoquiam, though most crews travel well beyond their home city.
Slab-on-grade foundations typically run $6 to $14 per square foot of footprint, crawl spaces $8 to $20, and full basements $30 to $100 or more depending on depth, wall height and waterproofing. A foundation for a typical 2,000 square foot house therefore ranges from roughly $12,000 for a simple slab to $60,000 or more for a basement in a cold climate.
Ranges are national and approximate; regional labor rates, material prices and site conditions move them in both directions.
Slab-on-grade foundations typically run $6 to $14 per square foot of footprint, crawl spaces $8 to $20, and full basements $30 to $100 or more depending on depth, wall height and waterproofing. A foundation for a typical 2,000 square foot house therefore ranges from roughly $12,000 for a simple slab to $60,000 or more for a basement in a cold climate.
Send the stamped structural plans, the soil report, the survey with corner stakes and elevations, the truck access route, and the framing start date the foundation has to be ready for.
The main cost items are foundation type, footprint, wall height and the rebar and concrete volume the plans call for; excavation depth, soil bearing capacity, groundwater and any over-excavation or engineered fill; formwork, pumping, waterproofing, footing drains, anchor bolts and backfill. A site visit helps the crew see which ones apply.
Foundation work is always covered by the building permit, and the footing inspection has to pass before any concrete is placed. Many jurisdictions also require a foundation survey or as-built before framing to confirm setbacks, and engineered systems need the engineer's letter of observation.
Directory
153 contractors found

demolition, driveways, erosion control, excavation, foundations, grading

demolition, driveways, excavation, foundations, septic systems

Edgewood, WAPierce County
demolition, driveways, erosion control, excavation, foundations, grading

demolition, driveways, erosion control, excavation, foundations, grading
10 years in business

Longbranch, WAMason County
driveways, excavation, foundations, grading, land clearing, paving prep
10 years in business

Hoquiam, WAGrays Harbor County
demolition, driveways, erosion control, excavation, foundations, grading

Duvall, WA
concrete cutting removal, demolition, driveways, erosion control, excavation, foundations

Castle Rock, WACowlitz County
driveways, erosion control, excavation, foundations, grading, hauling trucking

Tumwater, WAThurston County
driveways, erosion control, excavation, foundations, grading, land clearing

demolition, excavation, foundations, land clearing

Morton, WALewis County
demolition, driveways, erosion control, excavation, foundations, hauling trucking
3 years in business

Port Angeles East, WAClallam County
driveways, excavation, foundations, grading, land clearing, site prep

Davenport, WALincoln County
concrete flatwork, excavation, foundations, grading, site prep, trenching underground


demolition, excavation, foundations, grading, hauling trucking, land clearing

demolition, driveways, excavation, foundations, grading, land clearing
37 years in business

demolition, driveways, excavation, foundations, septic systems, site prep

driveways, excavation, foundations, grading, land clearing, site prep
30 years in business

Seattle, WAKing County
concrete cutting removal, demolition, driveways, excavation, foundations, grading

demolition, driveways, excavation, foundations, grading
30 years in business
Tell us about the job and add photos. A local pro calls you back. Free, and no spam.