Quote:
I'm not sure where you're getting that... no, you do not at all need to put plywood under them, indeed it's a real bad idea with the cheap pvc/vinyl stuff (it overheats and has an even shorter lifespan that way), but you need to make sure that the spacing of your rafter and purlin type supports is not too wide.
Typically, panels specify rafters no further than 2' apart, so if your little slanty ramp roof will only be 2' wide then the supports on either side are all you need in that direction. If it will be 4' wide, you'll need a middle one too.
Likewise for the purlins (crosswise supports that you actually screw the roofing into), typically you need them no more than 2' apart, so you will only be using a 2' length of roofing then it's sufficient to just support the top and bottom edges but if it will be longer than 2' long (measuring down the slope of the roof) then you will need one or more intermediate supports.
It would seem that your roofing is not plastic, it is Ondura type stuff, btw. I have not installed that personally so you need to get the mfr's pamphlet (ask at store or google for online version) to find out their specs. Although it is likely to be fairly similar to what you do for plastic and metal (as described above)
Pat
I'm not sure where you're getting that... no, you do not at all need to put plywood under them, indeed it's a real bad idea with the cheap pvc/vinyl stuff (it overheats and has an even shorter lifespan that way), but you need to make sure that the spacing of your rafter and purlin type supports is not too wide.
Typically, panels specify rafters no further than 2' apart, so if your little slanty ramp roof will only be 2' wide then the supports on either side are all you need in that direction. If it will be 4' wide, you'll need a middle one too.
Likewise for the purlins (crosswise supports that you actually screw the roofing into), typically you need them no more than 2' apart, so you will only be using a 2' length of roofing then it's sufficient to just support the top and bottom edges but if it will be longer than 2' long (measuring down the slope of the roof) then you will need one or more intermediate supports.
It would seem that your roofing is not plastic, it is Ondura type stuff, btw. I have not installed that personally so you need to get the mfr's pamphlet (ask at store or google for online version) to find out their specs. Although it is likely to be fairly similar to what you do for plastic and metal (as described above)
Pat