Concrete Lintel Repair Instead of Replacement, Southampton

The problem

A homeowner came to us directly about a concrete lintel showing spalling caused by corroding reinforcement. They came expecting a lintel replacement — but on site, we assessed the lintel and found it was in good enough structural condition to repair rather than replace.

The cause

Lintels sit directly above openings and take on extra moisture from window reveals, making them one of the first places reinforcement corrosion shows up. The rust expands and cracks the surrounding concrete from the inside out — but if caught before significant section loss has occurred, repair is the right route rather than replacement.

What we did

1. Honest assessment on site. Rather than proceeding with the replacement the client expected, we assessed the lintel and found we could repair it for significantly less cost and disruption. The client was happy to proceed with repair once this was explained.
2. Steel treatment. Exposed reinforcement treated with Fosroc Nitoprime Zincrich primer.
3. Reinstatement with Fosroc Renderoc. Applied over two days — there was too much depth to build up in a single application, so the repair was done in two coats. Fosroc products chosen for ease of finishing and decent finish quality.

The result

Completed over 2 days by one person. The client came expecting the disruption and cost of a full lintel replacement and left with a repair that achieved the same structural outcome for significantly less. Giving honest advice about what the job actually needs — even when the cheaper option is the right one — is how we approach every survey.