Amherst

Helical piles in Amherst, New Hampshire

Deep frost and rocky ground shape almost every New Hampshire foundation. A compiled frost-depth reference that cites local codes lists 48 inches for nearby Manchester, Nashua and Concord, and northern towns are colder still. Amherst's building inspector has the number that applies to your lot.

The New Hampshire residential code requires foundations to extend below the frost line set by the jurisdiction. Ledge and boulders are common, so a test pile helps confirm helicals will reach depth, and if rock is shallow the installer and engineer decide whether to move the pile or use a rock anchor. Helical piles also resist the uplift that heaves shallow deck posts every spring.

Helical pile companies serving Amherst

One Amherst company is in our directory.

• Solid Earth Technologies: installs helical piers for new construction, boardwalks, underpinning and wetland projects, and also offers grouted micropiles, earth anchors and retention walls.

Costs and what to ask

For a baseline, HomeGuide reports about $2,000 to $4,000 per installed helical pier across the U.S. Rock, depth and access affect New Hampshire pricing, and many deck projects need only a few piers. See our helical pier cost guide for what a written estimate should include.

Questions to ask any company quoting work in Amherst:

• Engineering: Does the engineer's design go below the frost depth the town requires, and what is the plan if ledge stops a pile?
• Torque logs: Can I get the final installation torque for each pier in writing?
• Galvanizing and shaft size: What shaft and helix sizes will be used, and what coating protects them in wet ground?
• Permits and warranty: Does Amherst need a permit for your project, and what warranty follows if a pile heaves?

Firms based outside Amherst are collected under New Hampshire helical pile installers.