Cracked Render Repair in Swindon
House rendering, K Rend & external wall insulation specialists. Free surveys, fixed written quotes, tidy workmanship.
Swindon Rendering diagnoses and repairs cracked render on houses across Swindon and Wiltshire. Before anyone quotes you for a repair, the crack needs reading properly — a hairline shrinkage crack and a stepped movement crack look similar from the pavement and mean completely different things for your wall and your wallet.
This page is the diagnosis, not the sales pitch. Work out which pattern you have, then decide whether you need a renderer, a structural engineer, or nothing more than a coat of breathable masonry paint.
The four crack patterns
Hairline crazing
A fine web of cracks under 0.5mm across a panel. Shrinkage in the render itself — mixed too strong, or dried too fast in summer sun. Cosmetic.
Straight cracks on a line
A dead-straight crack running the length of a wall, often at floor level or over a bead. Usually a missing or failed movement joint, or a corroding steel bead pushing the coat apart.
Diagonal and stepped cracks
Cracks over 3mm that step down through the wall or radiate from window corners. These are the building moving, not the render. Investigate before repairing.
Hollow and blown patches
Areas that sound drummy when tapped, often with a crack round the edge. Water has got behind the coat and frost has broken the bond. Always needs cutting out.
Crack diagnosis and cost bands
| What you can see | Likely cause | Typical fix | Cost band |
|---|---|---|---|
| Fine crazing, under 0.5mm | Render shrinkage | Stabiliser plus breathable masonry coating | £700 – £1,600 per elevation |
| Rust-stained straight crack | Corroding steel bead | Cut out, fit uPVC or stainless bead, refinish | £200 – £450 per length |
| Straight crack at floor line | Missing movement joint | Form a proper joint with bead and sealant | £300 – £750 |
| Cracks from window corners | Lintel deflection, no mesh | Cut back, mesh-reinforce, refinish | £250 – £550 per opening |
| Hollow patch, edges lifting | Water ingress and freeze-thaw | Remove to sound edges and re-render | £500 – £1,500 |
| Stepped crack over 5mm, widening | Structural movement or subsidence | Engineer's report first, then repair | £450 – £900 report, repair after |
2026 Swindon guide bands including access. Every job gets a fixed written quote after a free survey.
Cheap or serious — the honest test
Width and behaviour, in that order. Anything under 1mm that has not changed in a year is cosmetic and belongs to the render coat. Between 1mm and 5mm is worth watching. Over 5mm, stepped, and wider at one end than the other is the pattern BRE Digest 251 treats as significant damage, and no amount of filler fixes a wall that is still moving.
The other giveaway is where the crack sits. Cracks that follow the brickwork joints behind the render come from the building. Cracks that ignore the background and wander across panels come from the render. We repair to BS 5262 and BS EN 13914 practice either way, but only after the cause is settled.
How we assess before quoting
Tap survey across the whole elevation to map hollow areas you cannot see, a crack gauge on anything over 2mm, and a moisture check inside against the same wall. Where movement is suspected we fit tell-tales and leave them eight to twelve weeks rather than guessing.
General render repair
Blown patches, damaged corners and water damage.
Painting after repair
Breathable masonry coatings that bridge fine crazing.
Frequently asked questions
Ready for a free, no-obligation quote?
Call 01793 569534