Underpinning and Foundation Piers for a Settling House
Underpinning means extending or supporting a foundation so the house sits on deeper, firmer ground. When a corner or one side of a house sinks, piers driven or screwed into the soil carry the load past the weak layer to stable soil or bedrock. In another version of the work, the existing footing is dug out section by section and replaced with a deeper one.
Describe the job and add your city. Free to request, no obligation.
Houses settle for a handful of reasons: soft or poorly compacted fill, clay that shrinks in dry spells, soil washed away by leaking pipes or runoff, and footings that were never deep enough. The signs are cracks that keep opening, floors that slope and doors that rub, and the cause decides which method fits.
This is structural work. It almost always involves an engineer's assessment, a permit and a written scope, and it costs far more than patching a crack. That is the reason to be certain that the house is actually moving before committing to it.
What the work includes
- Surveying the foundation and recording where and how much it has moved
- An engineer's assessment or review where local rules ask for one
- Excavating at each pier location to expose the footing
- Driving steel push piers or screwing helical piers to the depth and load the design requires
- Attaching brackets that transfer the load from the footing to the piers
- Lifting the house back toward level where the structure allows it
- Backfilling and restoring the soil, patios or beds disturbed during the work
- A final survey and records of pier depths and loads
Signs part of the house is settling
Cracks run diagonally from the corners of windows and doors and keep growing
Floors slope or feel bouncy, with a visible dip across a room
Doors and windows stick, jam or leave uneven gaps
A gap opens between the foundation wall and the soil, or between the wall and the siding
A porch, chimney or addition is pulling away from the main house
Stair-step cracks follow mortar joints in brick or block
How the work goes, step by step
Describe the movement
Tell us about cracks, sloping floors, sticking doors and when you first noticed them.
Survey and diagnose
A local specialist inspects the house, may measure floor levels and decides if settlement is the cause.
Design the support
The pier type, spacing and depth are chosen from the load and the soil, with an engineer where required.
Written quote
You receive the number of piers, depths, method, permits, restoration and warranty terms.
Install and re-level
Piers go in, the structure is lifted if appropriate, and the site is backfilled and tidied.
What changes the price
- Number of piers
- Each pier has its own parts, labour and excavation, so the count drives the total.
- Depth to stable soil
- Deeper piers need more steel and more time, and some quotes charge by depth.
- Type of pier
- Push piers and helical piers differ in materials, equipment and suitability for the load.
- Access
- Tight side yards, finished basements, decks and landscaping make digging harder.
- Engineering and permits
- Drawings, reviews and permit fees are separate lines in many jurisdictions.
- Lifting and repairs
- Raising the house and repairing cracked walls and finishes afterward add scope.
What a good quote spells out
- The cause of the settlement stated plainly, and the evidence for it
- The pier type and why it was chosen, plus the number and depth of each one
- Whether an engineer designs or reviews the work and who arranges permits
- What happens if the soil conditions differ from what was expected when digging begins
- Warranty terms and what they cover, in writing
Underpinning & Pier Installation: questions people ask
What is the difference between push piers and helical piers?
Push piers are driven hydraulically using the weight of the structure and suit heavier buildings. Helical piers are screwed in to a measured torque and suit lighter structures, porches and additions.
Is underpinning the same as piering?
Piering is one way to underpin. Traditional underpinning digs under the existing footing in sections and pours a deeper one, and it is common when a basement is being lowered.
Will the house be lifted back to level?
Sometimes. If the structure allows, piers can lift it gradually. Often the aim is to stop further movement, since forcing a lift can crack finishes.
How can you tell the house is actually settling?
Look for cracks that keep growing, floors that slope and gaps at the corners. An assessment with levels and monitoring tells settlement from normal seasonal movement.
Does underpinning need a permit?
Often yes, and an engineer may need to sign off. Rules depend on the municipality, and a proper quote says who handles it.
Other Tidivex services
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