Hey Guys,
This is a little different from my normal cup of tea…
A terrific older couple from my church have some leaks in a clear corrugated plastic roof over a screened porch and I would like to repair it for them.
The roof appears to be about a 1 to 3 in 12 pitch and the longitudinal overlaps are one corrugation with clear (silicone) caulk in the overlaps. They are attached to factory cut corrugated wood purlns with rubber-grommeted machine screws.
I was there when it was *barely* raining yet water was coming through. I couldn’t pinpoint the leaks. Screws? Overlaps? Failed Silicone?
Do any of you have any experience at all with this stuff?
Thanks!
a.
Replies
Were the screws in the valleys? Anyway, try tightening the screws first - the gaskets weaken with exposure. Depending on the thermal movement, the holes may have elongated and not be covered by the gaskets.
You will be able to tell it the silicone has failed/doesn't work, 'cos there'll be a line where the rain comes thru.
On the other hand, it may be condensation dripping off...
All the best...
To those who know - this may be obvious. To those who don't - I hope I've helped.
I'll go back and look at these things. I might give it the garden hose test.Thanks!
a.
Good idea - may I suggest that you do it along the first 2 feet, then the next, etc...you'll be able to pin-point better that way.All the best...
To those who know - this may be obvious. To those who don't - I hope I've helped.
<<<do it along the first 2 feet, then the next, etc.>>>That's good advice.Thanks.
Our upper deck has this sort of roof. It's actually quite trouble-free, but can leak under the wrong conditions.
First check the gasket-head nails/screws -- look for any that have worked loose up or had their heads pop off. Note that all the nails SHOULD be on top of the ridges, not in the valleys.
The lap of adjacent sheets should be one full ripple (or sometimes one-and-a-half), with the edge of the top sheet ending in the valley of the sheet below. If the edge ends on top of a ridge then the sheets were installed upside-down or lapped the wrong way.
It should not be necessary to seal between adjacent sheets -- the overlap should suffice for all but extreme cases of wind-blown rain. Sealant in the wrong place could actually cause leaks by damming drainage.
A 2:12 slope is about the lowest you can expect the lapped seams to work right. If it's a real low slope there may not be much you can do.
happy?
Thanks for the info. Good tips. I'll try to take a look at it Saturday.