Foundation Contractor in Spokane, WA

Foundation contractor in Spokane, WA, forming and pouring footings, stem walls, shop foundations and PEMB footings that reach Spokane's 24-inch frost line. Raven Buildings digs, forms, sets the steel and pours foundations across Spokane and Spokane County with our own crews, for new homes, garages, additions, shops, barndominiums and pre-engineered metal buildings. Because we also do the dirt work and put up the buildings, the foundation is built for the structure that goes on it.

Foundation work we do

• Footings and stem walls: continuous footings and poured stem walls for homes, additions, garages and crawlspaces
• Monolithic and thickened-edge slabs: slab foundations for garages, shops and accessory buildings
• PEMB foundations: column footings, piers and anchor bolts set to the building supplier's reactions and anchor-bolt plan
• Barndominium and shop foundations: slab, stem wall or crawlspace, matched to the building and how it will be heated
• Retaining and below-grade walls: poured walls where the grade changes, built to permit when they need one
• Site prep: stripping, excavation, compacted fill and gravel base before the forms go in

Spokane foundation requirements

The City of Spokane and unincorporated Spokane County build to the 2021 Washington codes, with local design criteria:

• Frost depth: footings go at least 24 inches below finished grade in the City of Spokane (SMC 17F.040.105) and in unincorporated Spokane County (BUILD-07). Some nearby towns set it deeper, so we check the address before we dig
• Weathering: Spokane is rated severe for weathering, so concrete exposed to freeze-thaw needs air entrainment and higher strength
• Concrete strength (IRC Table R402.2): 2,500 psi for footings and foundation walls not exposed to the weather, 3,000 psi air-entrained for foundation walls exposed to the weather, and 3,500 psi air-entrained for garage floors, porches and steps
• Minimum footing size: under the residential code, footings are at least 12 inches wide and 6 inches thick, and wider when the soil and the loads on them call for it (IRC R403.1.1)
• Wall height above grade: foundation walls stick up at least 6 inches above finished grade, or 4 inches where masonry veneer is used (IRC R404.1.6)
• Foundation drains: foundations that hold back earth around habitable or usable space below grade need perimeter drains, except on well-drained Group I sand and gravel soils (IRC R405.1)
• Grading: the ground falls at least 6 inches in the first 10 feet away from the foundation (IRC R401.3)
• No pouring on frozen ground: footings can't bear on frozen soil, so winter pours need thawed, protected subgrade

Permits and inspections

• City of Spokane: foundations are part of the building permit for the structure, reviewed and inspected through the City's Development Services Center
• Spokane County: the County Building and Planning Department handles permits outside city limits; excavation for footings under a valid building permit doesn't need a separate grading permit (Spokane County Code 3.10)
• Footing inspection: the inspector checks the excavation, forms and steel before concrete is placed
• Commercial and engineered work: larger buildings and PEMBs on engineered foundations can add special inspection of the concrete and reinforcing under IBC Chapter 17, as listed on the plans

Why owners pick Raven for foundations

• One crew from dirt to building: we do the site prep, the foundation and the metal or pole building, so there's no gap between trades
• Anchor bolts set right the first time: we work from the PEMB supplier's anchor-bolt plan with templates, and we source PEMB packages from whichever manufacturer has the fastest delivery
• Local frost and snow experience: we build to Spokane's 24-inch frost line and confirm the local rule for every address

Foundation pricing

Foundations depend on the building's size, loads, soil and how much excavation the site needs, so we quote each one after we've seen the plans and the site. If the foundation is for a metal building or pole building we erect, the building itself runs about $60 to $75 per square foot installed, with electrical, plumbing and utility hookups extra, and the foundation is quoted with it.

Helpful guides

• Frost depth for footings in Spokane
• PEMB anchor bolts: design, tolerances and inspections
• Barndominium foundations: slab vs. crawlspace vs. basement
• Rebar vs. wire mesh vs. fiber in slabs
• Concrete driveways in Spokane

Get a free foundation quote

Call 509-350-2016 or request a free quote. Send your address or parcel number, the building's size and type, and your plans if you have them, and we'll get back to you with a price and a schedule.

Sources

• Building pricing: Raven Buildings' current rates
• City of Spokane, SMC 17F.040.105 Design Criteria
• City of Spokane / Spokane County Joint Policy BUILD-07, Official Frost Depth (PDF)
• City of Spokane BUILD-21 Engineering Design Standards (PDF)
• Spokane County BP-06 Residential Building Permits (design criteria)
• Spokane County Code Chapter 3.10 (grading), Municode
• 2021 International Residential Code, Chapter 4 Foundations (R402.2, R403, R404, R405)
• 2021 Washington Residential Code, Chapter 4 Foundations (UpCodes)
• ICC, 2021 IBC Chapter 17: Special Inspections and Tests