Most cost guides organise structural work by house size. That is the wrong axis. A foundation repair is priced by how many piers go in and how hard they are to install, and a waterproofing job is priced by how much earth has to move. Neither follows from square footage.
These are also the most labour-heavy jobs we track — around 65% of the total on both counts. That makes local crew rates matter more here than almost anywhere else: $45.42 an hour around San Jose, CA against $20.60 an hour around Gadsden, AL.
Access is the hidden multiplier
Exterior waterproofing means digging down to the footing around the perimeter of the house. If an excavator can get there, it is a machine job. If it cannot — a narrow side return, a mature tree, a neighbouring wall — it becomes a hand-dig, and hand-digging a perimeter trench is slow, expensive work that no square-footage rule captures.
The same logic governs pier installation. Open ground where a rig can drive to each location is one price. Piers under a conservatory or against a boundary wall are another.
Interior and exterior are not competing quotes
If you have been given one quote for interior drain tile and a sump, and another for exterior excavation and membrane, you have not been given two prices for the same job. They solve the problem differently and they last differently. The interior approach manages water that has already reached the footing; the exterior approach tries to stop it arriving. The exterior job costs several times more and is far more disruptive.
Before you compare anything. Get a diagnosis in writing — what is causing the water or the movement — from someone who is not selling you the repair. A structural engineer's report costs a fraction of the work and it is the only thing that makes competing quotes comparable.
What the material indexes tell you here
Concrete products have risen +3.7% in the twelve months to July 2026, and asphalt felts and coatings, which underlie most waterproofing membranes, have risen +4.6% in the twelve months to July 2026. Neither will dominate your quote — at roughly a third of the job, materials are the smaller half of structural work — but a large move in either is a reason to ask when a quote was priced.
Why we publish no figure for these jobs yet
Foundation and waterproofing work has no public installed-cost dataset we can cite. The variation is also genuinely enormous: a crack injection and a full underpinning are both "foundation repair", and any single national average that spans them is more misleading than useful. Our foundation repair and basement waterproofing pages carry the local wage data and the material trends, and say plainly that the total is not something we can source yet.