If you have filled the same crack twice and it has opened again, the filler was never the problem.
Surface filler covers a crack; it does not fill it. If the crack is still moving — and many are, with seasonal thermal movement — the filler cracks with it. If the crack is carrying water, the filler traps that water behind it and the wall stays wet, which is why the paint blisters again a few months later.
Injection grouting works from inside the structure. Ports are drilled into the crack at intervals, and a resin or grout is injected under controlled pressure so that it travels along the full depth of the crack, fills it from within, bonds the two faces together and cuts the water path.
The difference matters most where the crack is structural, or where water is under pressure behind it — basement walls, tank walls, construction joints. In those situations surface treatment is not a cheaper option; it is simply not a treatment.
Where it runs, how deep it goes, whether it is still active, and whether it is carrying water. An active crack and a dormant one need different materials.
Ports go in at intervals along the crack, angled to intersect it within the thickness of the structure.
The appropriate grout is injected port by port, working along the crack, until it travels and fills. Pressure control matters — too much can widen the very crack you are treating.
Ports are removed and the surface is finished so the repair is not visible.
Where the crack was carrying water, the real test is the next period of rain, and we would rather come back and check than assume.
Injection grouting is the right technique for structural cracks in walls, columns and slabs; for construction joints that have started to leak; for basement walls under water pressure; for leaking cracks in tanks and sumps; and for wall seepage where water is tracking through one specific defect rather than through the whole wall.
It is not the right technique for general dampness spread across a wall surface, or for rising damp. If that is what you have, we will tell you, because injecting it would waste your money.
Where bathroom water has reached a slab crack, both need treating.
We will come and look, tell you what is actually causing it, and quote only what it needs.
Waterproofing, heat proofing and construction contractor based in Agra, Uttar Pradesh. 35+ years on site, authorised applicator for Sreechem Resins Limited, and a free inspection before any quote.
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