Diagnosis & repair
Cracked Liquid Screed — Diagnosing and Fixing It
Not every crack is a problem — but the ones that are can wreck the finished floor above. Here's how to tell the difference.
Most cracked screed jobs we're called into fall into three categories: shrinkage cracks (cosmetic), shakes at door thresholds (movement — needs sealing), and structural cracks (something below is moving).
This page walks through diagnosis before repair, because a wrong fix on the wrong crack makes it worse.
Crack type quick-reference
| Crack pattern | Likely cause |
|---|---|
| Fine map cracks across a room | Surface shrinkage — cosmetic |
| Straight line at a door threshold | Movement — needs a mastic joint |
| Crack that runs wall to wall | Slab movement below — investigate |
| Corner cracks near columns | Restraint cracking — repair with epoxy resin |
How we repair
- 1
Inspect
Chalk-line the cracks and check with a straight-edge for level change either side.
- 2
Chase
Open the crack to a small V with an angle grinder.
- 3
Resin
Two-part epoxy resin injected — restores tensile strength across the crack.
- 4
Overband
For tile-ready surfaces, band with a de-coupling membrane before tiling.
Frequently asked
Cracked floor?
Send a photo and we'll tell you if it needs repair or if it's cosmetic.