Pier and beam repair, where the wood usually fails first

What is pier and beam repair?

A pier-and-beam house is carried on a grid of piers with timber girders running between them, joists on top, and a ventilated crawl space underneath. Repair means restoring that support system where it has failed - re-shimming or replacing supports that have dropped, correcting piers whose footings have settled, and replacing girder, sill or post timber that has rotted. On these houses the wood is usually the weak link, and moisture is usually why.

Signs you need pier and beam repair

• A floor that dips toward the middle of the house or toward one interior wall, rather than toward an outside corner
• Bounce or deflection when you walk across a room, or dishes rattling as you cross the floor
• Interior doors on the ground floor that swing open or closed on their own, or that have started rubbing at one corner
• Visible gaps under baseboards on one side of a room, with the trim still tight on the other
• A crawl space where a support column no longer bears squarely - shims fallen out, a post standing on the soil, or a block pier out of plumb
• Girder timber that is soft to a screwdriver point, discoloured at the bearing points, or crumbling where it meets a pier
• Standing water, damp soil, or a musty smell that never leaves the crawl space
• Skirting or perimeter wall that has cracked or separated in a way that follows a single settled pier

Seeing something not on this list? Browse foundation repair problems by symptom →

How pier and beam repair actually works

1. 1

   Establish where the floor actually is, in numbers

   A relative elevation survey across the whole floor plan turns "it feels sloped" into a map of where the support system has dropped and by how much. On a pier-and-beam house this immediately distinguishes a single settled pier from a girder sagging between two sound ones.

   Watch forA proposal that names a pier count before anyone has measured the floor. On this construction type the low point tells you which supports to look at, and skipping it means supports get added where they are easy to reach rather than where the floor needs them.

2. 2

   Get into the crawl space and probe the wood

   Every girder-to-pier bearing point, the sill plates on the perimeter, and the base of every interior post get checked with a probe. Rot rarely announces itself on the surface - timber can look sound and be soft a quarter inch in, especially at the end grain where it sits on masonry.

   Watch forAn assessment done from the access hatch with a flashlight. Bearing points are where this system fails and they are distributed across the entire footprint, so a report that only describes what was visible from the opening has not seen the problem.

3. 3

   Separate the wood failures from the pier failures

   A dropped floor has two very different causes: the pier moved down into the soil, or the wood on top of it lost section and crushed. The remedy, the price and the durability all diverge from here, and both can be present in the same house.

   Watch forEverything being attributed to settlement. Shimming a rotted girder back up transfers load onto compromised timber and buys a season or two. If rot is present, adding support without addressing the wood is treating the symptom.

4. 4

   Deal with the water before rebuilding into it

   Rot needs sustained moisture. Standing water, a downspout discharging beside the crawl vent, a plumbing drip, grade sloping in - the source has to be identified and interrupted, or new timber sits in the same conditions that destroyed the old. The vapour and encapsulation half of that conversation belongs to crawl space encapsulation, not to this repair.

   Watch forA structural proposal that never mentions where the water came from. New pressure-treated girders in a wet crawl space still fail at the connections, the fasteners and the untreated members they bear against.

5. 5

   Correct the failed supports

   Depending on the finding this means new footings under settled piers, replacing deteriorated block or timber posts with properly bearing supports, or reworking supports that were installed on inadequate footings by a previous owner. Each support needs to land on something capable of carrying it, not on the soil surface.

   Watch forNew posts set directly on grade or on a single patio paver. It is quick, it looks like a repair, and it settles again - usually within a few seasons, and usually after the warranty conversation has been forgotten.

6. 6

   Replace compromised girders, sills and posts

   Rotten timber is cut back to sound material and spliced or replaced, with temporary support carrying the load while the work happens. Sill plate replacement along a perimeter wall is slower and more invasive than any of the pier work, which is why it is the item most often quietly left out of a quote.

   Watch forRot found "only where we could reach". Ask specifically whether every bearing point was probed and what was found at each, because the ones behind ductwork and plumbing are the ones nobody wants to reach.

7. 7

   Shim and adjust the floor deliberately, not maximally

   Once the supports are sound, the floor is brought up in controlled increments using shims or adjustable supports. How far it goes is a decision with consequences upstairs - the framing, finishes and plaster have adapted to their current geometry over decades.

   Watch forA promise to bring the whole floor back to flat in one visit. Fast, aggressive adjustment on an old timber house is how you produce new cracks in plaster and doors that suddenly do not close. Agree the target and the pace in writing before work starts - see foundation leveling for that decision in full.

8. 8

   Re-measure and hand over a record

   The elevation survey gets repeated after the work so there is a documented before and after, along with a record of what was replaced, what was shimmed and what was left alone. That record is what any future inspector - or buyer - will want.

   Watch forA one-line invoice describing "foundation repair, per proposal". You want the support locations, the members replaced, and the final elevations, because in five years nobody will remember which supports are new.

What does pier and beam repair cost?

Pier-and-beam work ranges from a modest visit to re-shim a few supports to a substantial project once girder or sill replacement is involved. Wood replacement, crawl-space access and the number of supports needing new footings drive the number far more than the house's square footage does.

See the full pier and beam repair cost guide - by material, size and region →

If the number is the problem, here are the ways people pay for it →