Crack stitching for cracked brickwork

Once a wall has cracked, the two sides behave as separate panels. Stitching reconnects them. Slots are cut into the horizontal joints across the crack, a thin twisted stainless bar is bedded in grout inside each one, and the joints are pointed over so the repair almost disappears. Because the work stays within the existing wall, there is rarely any need to take brickwork down, and most houses are stitched in a day or two.

Stitching is a repair, not a cure. It does not stop a wall that is still moving, so anything driving the crack, such as a leaking drain, a thirsty tree on clay, failed wall ties or a sagging lintel, has to be dealt with first. Done in that order, a stitched wall usually stays closed. Done the other way round, a new crack often opens beside the old one within a season or two.

What are the signs you need crack stitching?

• A crack you can fit a coin into, running through bricks and mortar
• Filled cracks that keep reopening along the same line
• Stepped cracking beside a window, door or corner
• Bricks split clean through where the crack crosses them
• A crack visible on both the inside and outside face of the wall
• Cracking that a surveyor or engineer has said is now stable

What causes it?

Movement that has since stopped

Historic subsidence, settlement of a new extension or an old drain leak that has been fixed often leave cracks behind once the movement ends. This is where stitching is most useful, because the wall only needs reconnecting. Evidence that movement has stopped, such as unchanged measurements over time, gives the repair the best chance.

Weak points around openings

Walls are weakest at window and door heads, under sills and at corners. Small movements concentrate there, and cracks run from the corners of openings. Stitching above and below the opening spreads the stress back into the surrounding brickwork, often alongside work to the lintel or arch.

Thermal and drying movement

Long runs of brick or block expand and shrink with the weather. Where no movement joint was built in, a vertical crack eventually forms. Stitching closes it, but if the wall still needs room to move, a proper movement joint may be the better answer, and we will say so.

Poorly bonded junctions

Extensions, bays and later walls are sometimes butted against the original house with little or no bond. The joint opens into a crack that runs the full height. Stitching or tying across the junction can reconnect the two, provided neither part is still settling.

How is it repaired?

How much will crack stitching cost?

The total depends on the combined length of cracks, how many need bars on both faces, the height you need to reach and whether internal making good is included. Very short runs of stitching are priced at the minimum visit charge.

See regional prices on the prices page or work out a guide price for your home with the guide price tool.

What happens, step by step?

1. Confirm the cause has stopped

   Before quoting we check what made the wall crack and whether it is still moving. If there is doubt, we suggest a period of monitoring or an engineer’s view, rather than stitching a crack that will simply open again.

2. Set out the bars

   Bar positions are marked across the crack, typically every few courses up its full height, with each bar extending well into sound brickwork on both sides. An engineer’s specification, where there is one, sets the exact spacing and length.

3. Cut, clean and grout

   Slots are cut into the bed joints to the right depth, dust is blown and washed out, and grout is placed. The bars are pressed home and covered, and the crack line is filled or injected.

4. Repoint to match

   The cut joints and crack are pointed in a mortar chosen to match the colour, texture and strength of the existing work. On older houses with soft bricks, a lime mortar is used so the repair does not trap moisture.

5. Make good and record

   Internal plaster cracks are cut out and filled where included, and dust is cleared. You receive a short note of where the bars went, which is useful for future buyers, surveyors and any insurance file.

How long will crack stitching take?

A single stitched crack is often finished in a morning, and a whole house rarely needs more than one to three days.

Do you need building control or a party wall notice?

What if you have an insurance claim open?

Stitching is often the final repair in a subsidence claim, carried out after the loss adjuster is satisfied the movement has stopped. If you think your cracks are subsidence-related, tell your insurer before permanent repairs start, because stitching first can remove the evidence. The insurer may want the crack measured for as long as 12 months beforehand. We can price to your loss adjuster’s or engineer’s schedule, with any extra work you want quoted separately.

Crack stitching: frequently asked questions