Stop Foundation Cracks Before Winter Freeze-Thaw Hits
Tiny cracks in basement walls grow fast once water enters and the seasonal freeze-thaw cycle begins. Boston Concrete identifies each crack's type and condition, then routes, cleans, and injects or seals it with the right material. No guessing, no generic fixes. Every assessment is free and every quote is written.
Polyurethane or epoxy injection selected per crack
Written quote, scheduled work, no surprises
Small now, structural later
Why Catching Cracks Early Saves Thousands
A thin vertical line running down a basement wall in October looks harmless. By March, after the freeze-thaw cycle has worked it, that line is wider, water is seeping through, and the repair cost has tripled. Early intervention is the cheapest insurance a homeowner can buy.
We measure and photograph each crack, determine whether it runs vertically or horizontally, whether it is actively moving or stable, and whether it is dry or weeping. That classification drives the repair method. A dry vertical hairline gets sealed at the surface. A weeping crack gets polyurethane injected through ports at full depth. Horizontal cracks that suggest pressure or structural movement get flagged for a different conversation.
We photograph, measure, and classify each crack as vertical or horizontal, active or stable, dry or weeping. This determines whether the fix is a surface seal or a full-depth injection.
Route the crack and install ports
The crack is routed to a clean profile where needed, dust and loose material are removed, and injection ports are spaced along the crack so the material reaches the full depth.
Inject polyurethane or epoxy
Active or weeping cracks receive flexible polyurethane injected through the ports, bonding and expanding to seal the full depth. Stable dry cracks are sealed at the surface.
Trim ports and verify the seal
Injection ports are trimmed flush, the wall is cleaned, and the repair is inspected after curing. Pairing with foundation installation or basement waterproofing is recommended for exterior risk.
Not all cracks are created equal
When Crack Repair Isn't the Right Answer
Horizontal cracks across a wall, stair-step patterns in block, or cracks that widen and narrow with the seasons all point to structural movement or soil pressure. These are not cosmetic issues and injecting over them is a waste of money.
When we encounter those patterns, we flag them immediately, refer to underpinning or structural foundation repair, and quote that work separately. We will not inject a crack that is a symptom of a bigger problem.
Hairlines versus horizontals, polyurethane versus epoxy, and when to call a structural engineer.
Most do, even hairline ones, because once water gets in and the freeze-thaw cycle takes over, a cosmetic crack becomes a leak. Sealing or injecting it early is much cheaper than fixing it after it has opened up.
Polyurethane is flexible, expands on contact with water, and is our default for active or weeping cracks. Epoxy is rigid and structural, used when bonding the two sides of the crack permanently is the goal. We choose based on the crack.
Yes, most cracks are injected from the inside through ports drilled into the wall, which avoids excavation. Exterior repair is reserved for cases where outside conditions are causing the crack or where pairing with waterproofing is the right call.
Usually yes. Horizontal cracks suggest the wall is being pushed by soil pressure or water; that is a structural issue and gets referred up to foundation repair. Vertical hairlines are usually just shrinkage and routine to fix.
A typical injection takes a few hours and the crack is sealed by the end of the visit. Larger or multiple cracks may take a day. The timeline is in the written quote so you know up front.
Homeowner reviews
What Boston Homeowners Say About Their Crack Repairs
Hairline crack started weeping last spring. Injected from inside in one visit, sealed up properly, and it has stayed dry through the next season. Cheap and done.
H. W.
Boston
★★★★★
They flagged one of my cracks as horizontal and recommended a structural look instead of just injecting. Could have charged me, didn't. That kind of honesty is rare.
I. R.
Quincy
★★★★★
Three vertical cracks injected in one visit. No mess, no fuss, no return leaks. Quote was firm, work was clean, ports trimmed off so you barely see them.
P. N.
Cambridge
★★★★★
Classified each crack on the wall and only repaired the ones that needed it. The rest were stable shrinkage and didn't need a thing. Saved real money.
V. L.
Somerville
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Describe the cracks you see, where they are located, their size, and whether they are leaking. We will inspect the wall at no charge and provide a written repair quote.
