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Tried lime mortar on a Victorian repoint job vs Portland cement mix
I did a small test area with Portland first last spring on a terrace house in Brighton, and it just cracked after 3 months. Switched to NHL 3.5 lime and worked it wetter like the old guys told me, no cracks at all so far. Any of you guys had better luck with one over the other on period brickwork?
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bettywood2d ago
Hear what you're saying about breathability, that's the whole thing. I've seen Portland trap moisture behind brick so bad it turns the face into dust after a few winters, especially on the south coast where it's damp. Lime lets the wall dry out naturally, and if you get the mix right it actually sticks to the old bricks instead of fighting them. The trick is keeping it damp while it cures, otherwise it can crumble too fast.
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