Lean to greenhouse leaking rain.

13 Oct 2010
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United Kingdom
I have constructed a 6 x 4 lean to polycarbonate against the wall (of course) but as the wall is uneven I fastened it against wooden battening. The only problem is the rain sits on the battening adjacent to the roof and seeps down through the crack. I would have thought after sealing with silicone sealant this would have stopped the water. Not the case

Ant tips on how to stop this. Obviously I will have to put something over the wood to divert the water down the sloping roof.
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Silicone sealant, as with most other types will eventually fail due to excessive movement.
You need to install a lead flashing that will move with the roof but also keep it watertight.

I dare say you would have some success with flashband though this does require some diligent fitting work and is still not 100% reliable. I wouldn't personally.
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