Home › Crack repair
$400–$950 per crack, poured walls
Foundation Crack Repair in Schenectady, NY
Most foundation cracks are not structural. A vertical crack in a poured wall is usually shrinkage, injectable in about two hours for a few hundred dollars. A horizontal one is a different animal. Here's how to tell them apart before you call anybody — and why none of this applies to a stone wall.
(518) 617-4320Send a photo with a coin beside it for scale and we'll tell you what you're looking at.
Reading the crack
Direction tells you cause, and cause tells you cost.
Vertical — usually fine
Concrete shrinks as it cures and cracks where it's weakest, often mid-wall or beside a window opening. These run hairline to about an eighth of an inch, roughly even in width top to bottom, and appear within the first few years of a pour. They leak, which is a nuisance, but they aren't a structural concern. Injection resolves them permanently.
Diagonal — worth a look
Running at an angle, often from a corner or a window corner, usually meaning one part of the foundation has settled more than another. Stable and hairline, it gets injected like any other. Wider at one end, or with the two faces out of plane, something is still moving and sealing it is premature. That's a conversation about why before it's a conversation about filling.
Horizontal — stop
A horizontal crack, especially around the middle third of the wall height, means lateral soil pressure pushing inward. On block walls it often shows as stair-stepping through mortar joints as well. This is a structural condition, not a leak, and injecting it hides the evidence without addressing anything. It needs stabilizing.
Rule of thumb: if a nickel fits in it, if it's horizontal at any width, if the two faces don't sit flush, or if it's visibly wider than six months ago — get eyes on it before sealing anything.
Photograph it with a coin beside it and we'll tell you which category you're in. Call (518) 617-4320.
How cracks get repaired
Polyurethane injection — for active leaks
Injection ports go in along its length, the surface is sealed over, and expanding polyurethane is pumped in under pressure. It foams to fill the full depth and stays flexible afterward, which matters in a climate that moves every foundation seasonally. Standard fix for a crack that leaks. Two hours, no excavation, works on a damp crack.
Epoxy injection — for structural bonding
Same delivery, different chemistry. Epoxy cures rigid and ends up stronger than the surrounding concrete, welding the wall back into one piece. Right where the crack has structural significance and the wall won't move again. Wrong where it will keep moving seasonally, because rigid material in a moving joint simply cracks again alongside the repair.
Exterior excavation and patching
Sometimes the right answer — a crack at or below the footing line, an unusable interior face, or a wall you're already digging. Dig, clean, patch, membrane, dimple board, backfill.
Carbon fiber over an injected crack
Where a crack is stable but you want assurance it stays that way, a carbon fiber strap bonded across it after injection prevents further widening. Common on a diagonal where settlement appears to have stopped and nobody wants to bet the house on it.
Why none of this applies to a stone wall
This matters more in Schenectady than in most places, because so much of the housing stock predates poured foundations entirely.
Injection assumes a solid wall with a defined crack. A rubble wall is neither — it's several hundred stones in mortar, and water passes through open joints across the whole face rather than at one point. Resin pumped into it migrates into voids and accomplishes little. A hollow block wall is a similar problem for different reasons: inject a core and the resin disappears into it.
On block, the approach is repointing failed joints, parging the interior face, and drilling weep holes into the bottom course so water trapped in the cores can escape into a drain. On stone, it's repointing with an appropriate lime-based mortar plus drainage. In both cases crack repair alone is rarely the whole answer — it's one line item in a drainage job. Any contractor proposing injection on a fieldstone cellar hasn't looked at the wall.
How to monitor a crack properly
- Mark both ends with a pencil line across the crack, and date them.
- Measure the width at the widest point and write it on the wall beside the date. A crack gauge costs a few dollars; a ruler will do.
- Photograph it with something for scale in frame.
- Repeat in three months, and again after the spring thaw — that's when movement shows up here.
- Any measurable widening, or the ends extending past your marks, means it's active. Call someone.
Seasonal fluctuation in a hairline crack is normal; foundations in this climate move a little every year with frost. Progressive widening that doesn't come back is not.
What it costs
Per crack, poured wall, standard height. Two hours.
Per crack. Structural bonding on a stable wall.
Repointing, parging, weep holes. Usually with drainage.
See the stone foundation page — different job entirely.
Per location, where it can't be addressed inside.
Most contractors price a second and third crack on the same visit lower, since mobilization is already covered. If you have three, ask — you shouldn't pay three call-out charges.
Crack repair questions
Will injection hold permanently?
On a poured wall with a stable crack, yes — the repair ends up more flexible and at least as strong as the concrete beside it, and most reputable installers warrant it for the life of the structure. What voids it in practice is the wall continuing to move, which is why diagnosis matters more than material.
It only leaks sometimes. Is that better or worse?
Normal, and informative. A crack that leaks only during heavy rain or the thaw is responding to water arriving faster than the soil can drain it away — fixing gutters and grade sometimes stops it without touching the crack. One that leaks constantly points to a genuinely high water table, which is a drainage conversation.
Can I use hydraulic cement from the hardware store?
For a small non-structural crack that isn't leaking, it's a reasonable cosmetic patch. It's a surface repair — it fills the outer half inch and does nothing about the depth, and water under pressure eventually finds its way around. It also makes proper injection harder later, since ports need a clean crack. If it leaks, skip it.
There's white powder on the wall. Problem?
Efflorescence — mineral salts left behind as water moves through masonry and evaporates. Not harmful itself, but proof water is passing through the wall, and it maps exactly where. Scrub it off; if it returns you've confirmed active moisture movement.
My foundation is stone. Where do I start?
With drainage, almost always. Old rubble walls were built to weep and no injection changes that. Get water away from the outside, intercept what remains at the footing, and the wall stops being wet enough to matter. Repointing then keeps the masonry sound. That order — water first, mortar second — saves people a lot of money.