Foundation piering
Piers carry part of the house's weight down past the most active clay. Here is what the common types are and how to read a pier proposal.
A foundation pier is a column installed under a beam to hold the house up from deeper, steadier ground instead of from the topsoil that shrinks and swells. Around San Angelo, the most active part of the soil is the upper few feet of clay, where USDA soil descriptions record cracks reaching as deep as 60 inches. Piers aim to get below that zone, or to a point where they stop advancing.
What are the common pier types?
- Pressed concrete piers. Stacked precast concrete cylinders pushed into the ground with a hydraulic jack until they won't go further.
- Steel push piers. Steel pipe sections driven down with the weight of the house as the reaction, usually until they reach rock or firm bearing.
- Helical piers. Steel shafts with screw-like plates that are turned into the soil, with the torque measured as they go. Useful for lighter loads and some additions.
- Drilled concrete piers. Holes drilled and filled with reinforced concrete, sometimes specified by an engineer.
How is the number of piers decided?
From the floor elevations and the spacing the system requires. The contractor marks where the beam has dropped and places piers along that run, typically every several feet. A proposal should show a drawing with each pier located, the type, and whether any are interior. If two bids differ a lot in pier count, ask each contractor to walk you through their elevation map.
What should you ask about depth?
- How deep do your piers typically go here, and what stops them?
- Will I get a log of the depth or pressure for each pier?
- What happens if a pier doesn't reach the expected depth?
Can piers cause problems?
They can if they're the wrong answer. Piering one side of a house that's actually heaving in the middle can create new cracks. That's why the cause matters as much as the hardware. When the stakes are high, an engineer's evaluation gives you a plan you can hand to any contractor.
What about the warranty?
Pier warranties vary in length, in whether they transfer to a buyer, and in what they cover: the pier itself, readjustment, or cosmetic damage. Get it in writing and read the exclusions, especially anything about drainage or plumbing leaks.
Pricing comes from the contractor after they've shot floor elevations and figured out what's driving the movement. We don't quote prices, and no honest contractor can price a pier job over the phone without seeing the house.
Where we connect you with help
Common questions
Which pier type is best?
There isn't one right answer for every house. Soil, load, access and the contractor's experience all matter. Ask why they chose the system they're proposing and what the alternatives would be.
Do piers need a permit in San Angelo?
Ask the contractor and the city. The City of San Angelo Building Permits & Inspections office, 52 W. College Ave., can tell you whether your scope needs a permit.
Related services
More background: San Angelo foundation guide.
Doors binding, brick splitting or a floor that's out of level?
Call and get connected with a foundation contractor who works around San Angelo.