Structural repairs for cracked, sinking and bowing walls

Most structural repairs cost from a few hundred pounds to several thousand, depending on the problem. As a guide, crack stitching is usually £80–£180 per metre of crack, a lintel £750–£2,500 per opening, wall tie replacement on a semi-detached house £2,500–£5,000 and underpinning £1,000–£3,500 per metre of wall. These are guide prices inc VAT; they vary by region and access and are confirmed in writing after a survey.

Prices vary mainly because labour, materials, parking, waste disposal and access costs differ across the UK. Guide prices are usually highest in London and the South East and lower in Wales, the North and Northern Ireland. Access matters as much as location: scaffolding, a narrow terrace or a busy road can add more than the region does. Your written quote reflects your own property.

Yes, the initial assessment from your photos or a call is free. From it we tell you whether the problem looks cosmetic, needs a site survey or calls for an engineer. After a survey you receive a no-obligation written quote, which becomes a fixed price in writing once the repair is specified. You are under no obligation to go ahead at any stage.

A crack is more likely to be serious if it is wider than about 5 mm, tapers from wide to narrow, runs diagonally from a window or door, passes right through the wall or keeps growing. BRE Digest 251 treats cracks up to about 5 mm as aesthetic in most cases. Sticking doors and windows alongside a crack are also worth noting. Width is a guide, not a diagnosis, and your engineer will confirm.

It is usually better not to fill a crack until it has been assessed, especially if it is new or getting wider. Filling hides the evidence of movement and can make an insurance claim harder to prove. Photograph it first with a tape measure across it, and mark the ends in pencil with the date. Fine, long-standing hairline cracks can be filled when you next decorate.

The usual signs are new diagonal cracks that are wider at one end, especially near windows, doors and bay junctions, plus doors and windows that suddenly stick. Cracks that appear or widen in late summer and close in winter often point to shrinkable clay and nearby trees. Rippling wallpaper, gaps under skirting boards and an extension pulling away can also be signs.

No, most subsidence claims are fixed without underpinning. Once the cause, such as a leaking drain or a thirsty tree, has been dealt with, the ground often stabilises and the cracks can be stitched and the walls made good. Underpinning is used only where monitoring shows movement is continuing or the foundations are clearly inadequate, and the engineer decides that.

Yes, houses that have had subsidence are sold regularly, though buyers and lenders will want evidence that it has been dealt with. Disclose past movement and claims honestly on the property information form. A certificate of structural adequacy from the engineer, the claim records and proof of continued buildings insurance usually help. Some buyers can take over the existing insurer’s cover, which is worth asking about.