Structural crack repairs in Greater London

Area: Greater London
Pricing region: London
Ground: Shrinkable clay widespread
Towns listed: 32

What should you know about the ground under Greater London?

Ground movement here is more often linked to soils, drains and trees than to mining. What you mostly find across Greater London: Victorian and Edwardian terraces with shallow footings, inter-war semis in the outer boroughs, and converted flats and mansion blocks.

Is it time for structural crack repairs? Common signs

Diagonal cracks running from the corners of windows and doors
Stepped cracks zigzagging through the mortar joints of outside brickwork
A crack noticeably wider at the top than the bottom, or the reverse
Daylight or a draught coming through a crack in an outside wall

What should you budget for structural crack repairs in Greater London?

Prices in Greater London are worked out on London rates. They include VAT and are a starting point: access, the extent of the damage and whether an engineer or building control is involved all move the figure.

Guide prices inc VAT on London rates. Items marked est. are our estimates.
Item	Guide price	Per
Crack stitching with helical bars	£100 – £225	per metre of crack
Single crack, outside only (up to about 2 m)est.	£500 – £1,100	per crack
Internal making good and redecoration of the crack lineest.	£190 – £625	per room

Repair options we may recommend

Crack stitching with helical bars

Stainless steel helical bars are grouted into slots cut along the bed joints, bridging the crack so the masonry works as one piece again. It is the standard repair for wider stepped and vertical cracks once whatever caused them has stopped.

Best for: Stable cracks wider than about 5 mm, or ones that keep reopening

Rebuilding a cracked section

Where bricks have split or the wall has moved out of line, the damaged area is taken down and rebuilt, bonded into sound masonry on either side. Reclaimed or matched bricks keep the repair discreet, with temporary support used where needed.

Best for: Badly displaced or broken brickwork

Filling and repointing

For hairline and narrow cracks that have stopped moving, the crack line is raked out and repointed in mortar matched to the original for strength, colour and texture. Inside, plaster cracks are cut out, filled with a flexible filler and redecorated.

Best for: Cracks up to about 5 mm that are no longer moving

What to expect when we carry out structural crack repairs

Survey and record
On site we measure the width along the crack, note its pattern and check nearby drains, trees and openings. If the cause is unclear, gauges can be fixed across it and read over several months.
Written quote
You receive a no-obligation written quote listing each crack, the repair method chosen for it and the making good inside and out. Once the scope is settled, that becomes a fixed price in writing.
Repair and make good
Cracks are stitched, repointed or rebuilt as specified, with mortar matched to the existing wall. Internal crack lines are filled and redecorated where included, and you get a written note of what was done.

Common crack patterns in brickwork: stepped, vertical and horizontal. Indicative drawing, not to scale.

Do you need approval for structural crack repairs in England?

Like-for-like repairs such as crack stitching and repointing do not usually need building control approval in England, but anything that changes or strengthens the structure, such as underpinning or rebuilding a wall, does. If the work touches a party wall, the Party Wall etc. Act 1996 may apply.

Find structural crack repairs in your Greater London town

Your structural crack repairs questions

Why do houses in Greater London crack?

Most of Greater London sits on London Clay, among the most shrinkage-prone ground in the UK, with river gravels along the Thames. Subsidence claims here are among the most frequent in the country, especially after dry summers and near street and garden trees. Ground movement here is more often linked to soils, drains and trees than to mining. Only an investigation on site can say why a particular building has moved.

How much will structural crack repairs cost in Greater London?

On London rates, structural crack repairs starts from about £100 per metre of crack, including VAT. The written price depends on the extent of the damage, access and whether an engineer or building control is needed.

Are horizontal cracks in a wall serious?

Horizontal cracks are often more serious than vertical ones, because they suggest the wall is being pushed or lifted. Cracks repeating every few courses point to rusting wall ties, while one long crack with a bulge may mean lost restraint.

What causes vertical cracks in walls?

Vertical cracks are most often caused by thermal or moisture movement in long walls, or by the joint between old and newer work. An even-width vertical crack is usually cosmetic. One clearly wider at the top or bottom can indicate foundation movement at one end.

Do I need a structural engineer for a cracked wall?

Not always, since many cracks can be judged from photos and a visit. An engineer is worthwhile when cracks are wide, tapered, growing or part of a claim. Where the repair needs an engineer’s design or sign-off, an independent chartered structural engineer is appointed, and we can arrange this.