Attempt to answer not only o.p. but questions raised by other posters on the thread:
There are TWO DIFFERENT KINDS (at least) of corrugated plastic roof. They are not equivalent.
PVC roofing panels, such as Palruf, are inexpensive and 'reasonably ok if that's all you want'. They are brittle and will not stand up to a hailstorm, and the warranty specifically excludes hail damage. They are also not designed for very hot temperatures (do not install over plywood roof sheathing; use with caution in a greenhouse-like environment e.g. solar collector) nor very cold temperatures (they are usually warranted down to 0 F only, presumably b/c of their brittleness in the cold, though it is not like they will disintegrate instantly at -1 F). They are a bit brittle and shattery to cut even at like 50 F, IME.
Polycarbonate roofing panels, such as Suntuf, are just about exactly twice the price as PVC ones. They typically have an unlimited lifetime warranty, are much more resistant to hail damage (and it's warranteed), and are rated for use down to -40 F and up to 270F. Thus they are a much much better choice for those up north and for those going to use 'em in ways that will get 'em real hot, e.g. over an existing roof surface or in solar collector arrangements. They do not get brittle when cold and are a joy to work with.
In the brands I've seen, the PVC panels have wavy corrugations while the polycarbonate ones have 'square' corrugations. I do not know whether there are exceptions to this rule however.
It is REALLY REALLY IMPORTANT to INSTALL ACCORDING TO MFR'S INSTRUCTIONS. If your sheet didn't come with an installation pamphlet, download one from the mfr's website. Get this BEFORE you build the supporting structure (rafters, nailers) to ensure the support structure meets the specs required by the materials. Also do not try to skip the wavy foam filler strips; unlike roofing tin, which is heavy gauge enough to screw through ribs without crushing, this stuff is really flimsy and *needs* that under there. (You can't screw it through the valleys instead, because then it will leak and rot its fasteners loose, b/c the holes have to be predrilled 'too big' to allow for thermal movement of the material)
Used as designed it is great stuff IMHO.
Slapped on any ol' whichway it is likely to fail prematurely (possibly spectacularly) and be a waste of money.
I use the polycarbonate stuff for some run roofs, and would like to replace the other (ancient snaggly disintegrating fiberglass) run roofs with Suntuf when budget allows. I give it a great big "three thumbs up" for the North -- it is *fine* for snow load when correclty supported. I would NEVER use the other stuff, PVC, for a cold windy or cold snowdrifty location however; and frankly even down south in a lot of places I'd be inclined to save my pennies up to get the polycarbonate, largely because of the hail warranty.
(edited to add: but in winterizing part of the cats' outdoor enclosure, which is very sheltered by bushes etc, I'm using clear pvc, because there should never be meaningful hail or wind hitting it, and it *is* after all half the price <g>)
JMHO,
Pat
