Tigard

Helical piles in Tigard, Oregon

Rain-soaked hillsides are one of Oregon's biggest foundation risks. The U.S. Geological Survey reports at least 1,700 landslides within Portland between 1928 and 2016, many in the West Hills, and DOGAMI publishes a homeowner's guide to landslides.

Helical piles fit sloped, wooded and tight-access lots because they reach firmer soil under loose colluvium with minimal excavation. The Oregon code requires footings at least 12 inches below grade, and west of the Cascades that minimum usually controls. Stabilizing an active slide is a separate engineering problem that needs a geotechnical engineer.

Oregon coastal and east-of-Cascades sites bring different conditions, but around Tigard the common questions are slope, soil strength and groundwater. Piles install without dewatering an excavation, which avoids adding water or spoil to a slope.

Helical pile companies serving Tigard

One company in the directory is based in Tigard.

• TerraFirma Foundation Systems: a Tigard company offering foundation piers, wall stabilization, basement waterproofing and crawl space repair across the Pacific Northwest. Helical evidence is limited in its listing.

Costs and what to ask

Typical installed pricing is roughly $2,000 to $4,000 per helical pier nationwide, about $3,000 common, according to HomeGuide. Oregon jobs on steep or wooded lots may cost more because of access and engineering. See our helical pier cost guide.

• Is the lot on a slope, and has a geotechnical engineer reviewed it?
• Will you provide torque and depth logs?
• What shaft size and galvanizing do you use?
• Who files with Tigard, and what does the warranty cover?

See Oregon helical pile installers for more Oregon companies.