Wilsonville

Helical piles in Wilsonville, Oregon

Rain-soaked hillsides are among Oregon's biggest foundation risks. The U.S. Geological Survey reports at least 1,700 landslides within Portland between 1928 and 2016, and DOGAMI publishes a homeowner's guide to landslides. Helical piles reach firmer soil or weathered rock beneath loose colluvium with minimal excavation, which avoids adding water or spoil to a slope.

West of the Cascades, the Oregon Residential Specialty Code minimum of 12 inches below grade usually controls, and the local table sets the frost value. Oregon is exposed to large Cascadia earthquakes, so engineered designs account for seismic loads, and lots in mapped landslide areas may need a geotechnical report. On sloped, wooded or tight-access lots, ask how the crew will reach the work and how the design avoids adding water to the slope.

Helical pile companies serving Wilsonville

One company based in Wilsonville is listed.

• Foundations First Northwest: Offers helical piles with foundation repair, wall stabilization, earthquake retrofit, waterproofing and crawl space repair in Portland and on the coast.

Costs and what to ask

HomeGuide reports that helical piers cost about $2,000 to $4,000 each installed nationally, with about $3,000 typical. Oregon jobs on steep or wooded lots may cost more because of access and engineering. See our helical pier cost guide for the main cost drivers. Questions to ask:

• Does my lot fall in a mapped landslide area that needs a geotechnical report?
• How does the engineered design account for seismic loads?
• Will you provide torque logs for each pile?
• What galvanizing is used, and who pulls the permit and covers the warranty?

Nearby listings include Portland and Tigard. See all Oregon helical pile installers.