What is a Helical Pier?
A helical pier is a pier that installers screw into the ground using a large drill motor. Helical piers work well in situations where the surface soil isn’t sufficiently supportive for a conventional foundation. When installers can reach stable soil 10 to 60 feet deep, the helical pier’s helices will support the home.
Designing Helical Pier Foundations
Helical-pier foundations typically require a geotechnical survey and a blueprint with an engineer’s stamp. Although, sometimes engineers and builders test-install various sizes of helical piers to evaluate the soil at various soil depths before designing the pier foundation or ordering the helical piers.
Installation and Attachment
During installation, the installers measure the torque at the drill motor to determine at what depth that the helical pier that they’re installing will support its share of the home’s weight. Installers use helical piers with and without concrete. Installers embed the piers head in a concrete footing or attach the piers to the home’s main supporting beams.
This post is borrowed from the book Northern Comfort, soon to be published by the Alaska Craftsman Home Program (ACHP), which I’ve been editing, rewriting, and re-illustrating.