Crack Stitching and Expansion Joint, Retaining Wall, Guildford

The problem

A landlord came directly to us about a retaining wall with multiple cracks. Most were relatively minor, but one crack in particular had displaced significantly more than the rest.

The cause

The majority of the cracks were standard movement-related separation that helical bar crack stitching would address. The one large displaced crack was a different problem — it had moved too far for a mortar repair to look right. Trying to fill and point it to match the surrounding brickwork would have been obvious and unconvincing.

What we did

1. Crack stitching to the minor cracks. Around 20 6mm stainless steel helical bars, each 1 metre in length, were installed across the wall and bonded with two-part masonry resin. Stainless steel and two-part resin were chosen for strength and longevity.
2. Expansion joint to the major displaced crack. The one significantly displaced crack was cut straight and formed into a deliberate expansion joint rather than attempting a repair that would have been visible. Done properly, a formed expansion joint looks intentional rather than like a failed repair attempt.
3. Sand and cement finish. All pointing finished in sand and cement in bucket handle style to match the existing jointing on the wall.

The result

Completed by one person in a single day. The 20 helical bars addressed the crack stitching across the wall; the expansion joint addressed the one crack that had moved too far to repair. It’s important to be clear that the bars were installed across the wall as a whole — the expansion joint dealt specifically with that one displaced crack, not the wider programme of stitching.