R Scott wrote: You can build your own standing seam roof panels with roll flashing and a siding bending brake. No nail holes to leak.
R Scott wrote:plus...The cheap panels only seem to last 5-7 years before they get brittle and crack from branches or hail or strong wind.
R Scott wrote:http://youtu.be/p143ioJIQbg
Cristo Balete wrote:I've used polycarbonate panels on greenhouses for years. They aren't to code. And unless I'm missing something, here's my experience with them:
They don't block out all the light, so that leaves your insulation vulnerable to deterioration in the sunlight.
They are extremely noisy in the rain.
They rattle like crazy in strong winds.
Once you put a hole in it with even the proper screws with washers, a strong wind can make them tear if an edge gets caught for a long enough period. Steel roofing can withstand that better.
They aren't meant for heavy snow loads.
I wouldn't walk on them, even if they had lots of framing underneath them.
Any weak spot will be shaken loose in a wind storm, so you have to keep your eye on them all the time.
I've had roof rat/pack rats chew on/eat the spacers between the panels and the frame.
Some are corrugated, so closing up the ends is difficult, i.e., keeping out insects, driving rain.
You'd have to seal them to keep out moisture, which might not be possible. A house roof needs to breathe to handle moisture from inside and out.
They can get condensation on the underside.
Attics needs to be vented to keep the heat from getting too hot, they would let in way more heat than a conventional roof.
I've seen them used on barns and out-buildings where it doesn't matter so much about what's underneath them. Using wide strapping over them also helps keep them in place, which isn't practicable on a house.