Screed problems usually come to light at the worst possible time: when the flooring installer arrives, when tiles start cracking, or when a new floor starts to lift. Sometimes the problem is small and local. Sometimes the screed was never right in the first place. Either way, the repair has to deal with the cause, not just the symptom, or the same thing will happen again. K & B Screeding finds the cause before it repairs the floor.
We repair screeds in homes and commercial buildings across London and the Home Counties, and flooring contractors can call us in when they find a problem they cannot fit a floor over.
Common screed problems we repair
- Cracking. From fine shrinkage cracks to wide structural cracks that open and close.
- Hollow or drummy areas. Screed that sounds hollow when tapped, because it has lost its bond or was never compacted.
- Crumbling and dusting. A weak surface that breaks down under foot, usually from a poor mix, poor compaction or frost damage.
- Curling and lifting edges. Screed edges that rise at joints and doorways as the screed dries unevenly.
- Uneven levels. High spots, dips and ridges that will show through the floor finish.
- Damage from other trades. Service trenches, drilled holes and broken edges at doorways.
- Damp screed. Screed that will not dry because of a missing or damaged damp proof membrane.
Finding the cause first
Before we quote for a repair, we want to know why the screed has failed. We check how it sounds, how hard the surface is, whether cracks are moving, the depth where we can see it, and whether there is moisture in the floor. The cause decides the repair.
| Cause | Typical signs | Usual repair |
|---|---|---|
| Shrinkage | Fine cracks, often at doorways and corners | Crack repair and resin fill |
| Loss of bond | Hollow sound, cracks around the hollow area | Cut out and relay as a bonded repair |
| Poor compaction or weak mix | Crumbling, dusting, surface breaks up | Remove weak screed and relay |
| Too thin over insulation | Cracking and movement across the floor | Relay at the correct depth |
| Missing movement joints | Straight cracks across rooms and doorways | Form joints and repair cracks |
| Moisture | Screed will not dry, coverings lift | Membrane repair or replacement |
Swipe the table sideways to see every column.
How we repair screed
Crack repairs
Stable cracks are cut out along their length, cleaned and filled with a suitable resin or repair mortar. Wider or active cracks can be stitched across with metal ties set in resin so they cannot open further. The repaired area is then ground flush.
Patch repairs
Hollow, crumbling or damaged areas are cut back to sound screed with straight edges, the base is prepared and primed, and new screed is placed as a bonded repair flush with the surrounding floor. This is the most economical fix when the rest of the floor is sound.
Full replacement
When the problem runs through the whole floor, patching only delays the inevitable. We break out the old screed, correct whatever caused the failure, whether that is the insulation, membrane, depth or joints, and lay a new sand and cement or liquid screed floor.
Levelling after repair
Once the screed is sound, a levelling compound can bring the whole surface to the flatness the new floor finish needs.
Repair or replace?
A local repair makes sense when the problem is limited to one area and the rest of the screed is hard, well bonded and at the right depth. Replacement is the better value when the screed is weak throughout, too thin, hollow over a large area, or when the underlying cause affects the whole floor. We will always explain which we recommend and why, and our guide to floor screeding costs covers the factors that affect the price.
Before your new floor goes down
Repairs add moisture to a floor, and a repaired screed still has to be dry enough for the new floor covering. We will tell you how long the repair needs, and our guide on how long screed takes to dry explains how to check it is ready.
Screed repairs near you
We repair screeds across London and the Home Counties from our base in Slough, including Windsor, Maidenhead, Northampton and throughout London.
“From start to finish, K & B Screeding Ltd demonstrated exceptional expertise and a commitment to customer satisfaction. I am extremely impressed with the service that they provide.”
Part of our screeding and floor screeding services, laid by our own team across London and the Home Counties.
