What crack stitching does
Crack stitching is a repair method for masonry walls that have cracked because of movement. Stainless steel helical bars are bonded into mortar joints either side of the crack, bridging it and tying the two sides of the wall together. Done properly, it restores the wall's ability to act as a single element without the need to take it down and rebuild.
When it is the right repair
Not every crack needs stitching. Fine hairline cracks from old shrinkage or seasonal movement are often just filled and decorated. Stitching is considered where a crack is wide enough to let water in, runs through several courses of brick, is stepped along the mortar joints, or is found above openings such as windows and doors. Across Newcastle and North Tyneside we regularly see cracking in Victorian and Edwardian terraces, where shallow foundations, old drains and ground that has moved over many decades can all play a part.
Why the cause matters first
Stitching treats the symptom, not the reason the wall moved. Before any repair we look at what is likely to have caused the crack, such as leaking drains, tree roots, failed lintels, a lack of lateral restraint or past mining and ground conditions. If the movement is still active, the cause has to be dealt with first or the crack will simply reopen. Where the cause is unclear, we may recommend a structural engineer's opinion before work starts.
How the work is carried out
- Mortar joints are cut out along the line of the crack at set intervals
- Slots are cleaned and flushed so the bond is sound
- Stainless steel helical bars are set into a suitable grout or resin
- The joints are repointed to match the existing mortar as closely as possible
- Brickwork is repaired where bricks are broken or displaced
Because the bars sit inside the joints, the finished repair is discreet. On traditional buildings, matching the mortar colour and joint profile matters as much as the structural work, and in conservation areas such as parts of Tynemouth and Jesmond we pay particular attention to appearance. See also our lime mortar repointing service.
Related repairs
Cracking is often linked to other defects. Failed lintels may need replacing, and bulging walls may need separate treatment. Building Regulations approval is not always needed for repairs, but structural alterations may be. You can check the position on the Planning Portal.
Frequently asked questions
How do I know if a crack needs stitching?
Wide cracks, stepped cracks following the mortar joints, cracks that open and close, and cracks above windows or doors deserve a proper look. Hairline cracks are often cosmetic. We can inspect, explain what we find and say whether stitching or a simpler repair is appropriate.
Will crack stitching stop the crack coming back?
Stitching strengthens the wall, but it cannot stop movement caused by something else such as a leaking drain or tree roots. We look for the cause first, because fixing that is what gives the repair the best chance of lasting.
