Leaking Twin wall Polycarbonate roof

[zaax]

I'm having problems with Twin wall Polycarbonate roof in my conservatory. The fixing holes I have drilled leak even with the correct rubber washers / covers

What seems to be the problem is that the Polycarbonate expands in the sun and contracts when it rains and lets in the rain.

Any ideas on how to fix it?

-- zaax

[Rick]

The fixing screws should have rubber sealiers on the top, to deal with tiny movments. check you have the correct tighness.

Rick

[dave]

I had the same problem and fixed it by using proper polycarbonate flashing under each button. just a little square which diverts the water around the button. I had replaced all the buttons prior to this after the old ones leaked and broke due to the heat.

Dave