Case file — Gaithersburg, Montgomery County, MD. One of the 25 jobs in our 250-home series. New here? Start with our open letter.
At a glance
| Location | Gaithersburg, Montgomery County, MD |
| The problem | A leaking crack in a poured foundation wall — and then, weeks later, a different one |
| The fix | Two separate injections, each one drilled, packed, injected, cured and patched in full |
| Time on site | Two jobs, about seven weeks apart |
What injection promises, and what it does not
Injection seals the crack you inject. Through the wall, permanently, with a written warranty on that crack.
It does not make the rest of the wall stop being the same age, the same pour and the same concrete, sitting in the same ground. If the conditions that opened one crack are still there, they can open another one somewhere else, and no injection anywhere on the wall changes that.
This house is the clearest example of it in the series. One crack sealed in early summer. A second crack, in a different place, about seven weeks later.
Why this is not a failure
We want to be direct about this, because it is the point at which trust is usually lost.
If a company seals a crack and a new crack appears later, there are two things that could be happening, and they are completely different:
The sealed crack reopened. That is a failure, and it is what a warranty is for. Fixing it is not a new job and should not be a new invoice — we come back, as we did on a Kensington house in this same series.
A new crack appeared elsewhere. That is a new problem in a new location. It gets its own diagnosis and its own work, exactly as the first one did.
The second job at this house was the second kind: a full injection and a full finish, drilled, packed, filled, cured and patched, on a crack the first job never touched.
What we tell homeowners with multiple cracks
If a poured wall is producing cracks in more than one place, the question stops being how do we seal this line and becomes why is this wall moving or wetting the way it is.
Sometimes the answer is settlement, and the honest response is monitoring rather than more injection. Sometimes it is water pressure against that wall from outside, and the real fix is taking the water away before it reaches the foundation rather than sealing the wall one line at a time.
Sealing cracks as they appear is a reasonable way to handle a wall that produces one every few years. It is a bad way to handle a wall that produces one every few months — at that point you are paying repeatedly for a symptom.
The straight answer
Two cracks in one summer is not common, and it is not nothing either. This homeowner got both sealed properly and an honest conversation about what would mean it was time to look at the wall as a whole instead of crack by crack.