Rotated Boot Lintels Stabilised Without Replacement, Guildford

The problem

A homeowner came to us expecting boot lintel replacement after noticing cracking above two openings, both over 3 metres long. On site we found both boot lintels were structurally sound — they had slightly bowed and rotated, but the lintels themselves did not need replacing.

The cause

A boot lintel’s outer toe has no bottom bearing surface and relies entirely on the inner masonry leaf for support. Where that bearing isn’t capable of properly spreading the load, the lintel rotates over time — but rotation without structural deterioration of the lintel itself doesn’t necessarily mean replacement is needed. Replacing boot lintels over openings of more than 3 metres is very involved, expensive, and destructive. Masonry beaming was the right alternative.

What we did

1. Honest assessment on site. Having found the lintels were sound, we were able to offer masonry beaming as the significantly cheaper, quicker, and less disruptive alternative to replacement. This was agreed with the client before work began.
2. Joint raking. Two rows of mortar joints were raked out above each lintel to a depth of 50mm, extending at least 500mm beyond each side of the lintel. Thorough cleaning of each joint followed to ensure a clean bond for the grout.
3. Helical beam installation. Two continuous helical beams were installed in each raked joint — four beams per lintel in total, two per row — and fully bedded in cementitious grout to ensure continuous bond along the full length.
4. Pointing. All joints pointed in sand and cement in bucket handle style to match the existing jointing on the property.

The result

Completed by one person in a single day. The client came expecting a destructive, expensive lintel replacement across two openings of more than 3 metres and left with a masonry beaming repair that resolved the rotation at a fraction of the cost and disruption. There are no real alternatives to this technique for boot lintel rotation where the lintels themselves are sound — it’s the correct structural fix for the specific failure mode.