The word “sealant” makes people nervous with old brickwork — and rightly so. Seal a wall with the wrong product and you trap moisture inside it, which is worse than doing nothing. The key is using a breathable treatment that repels water from the outside while still allowing moisture vapour to pass through from the inside.
The products I use are silane or siloxane-based — they penetrate the surface of the brick rather than coating it. They’re invisible once applied and they work with lime mortar rather than against it.
I’d never apply a sealant to a wall that needs repointing first — that’s sealing in the problem. It’s usually the last step in a programme of works, not the first.
- Breathable silane/siloxane treatments — water repellent but vapour permeable
- Invisible in application — no change to colour or texture
- Protects against water ingress, frost damage and pollution
- Compatible with lime mortar — won’t cause the problems masonry paint does
- Only recommended where it’s genuinely the right solution
“Chris is a craftsman and master pointer. He recently repointed the whole side of a building for me. It was complicated by the fact he first had to rectify someone else’s mistakes. He made a really beautiful job of it. Chris is also a delight to deal with, I can’t recommend him highly enough.”
— Gill Brown, Islington