Corrugated sheet Plastic Vs bitumen?

[Ruggers]

Has anyone much experience with using Corroline type corrugated sheeting?
I'm wanting to cladd some to the back of a summerhouse (Non visible sides)
to keep the weather off it. The sides already have ply on with bitumen painted on but there are joins between the sheets.

I've narrowed it down to two types, polyurethane plastic type 1.1mm thich clear or the 2.3 mm bitumen type ones, not sure which would be best due to weight or life expectancy.

I know a greenhouse made from the plastic ones which has lasted 12 yrs so far and doing well.

http://www.roofingsuperstore.co.uk/...n-black-roof-sheet-2m-x-950mm-pack-of-15.html

http://www.roofingsuperstore.co.uk/browse/roof-sheets/3-profile/heavy-duty-sheets.html

 

[ladylola]

I've built my workshop with coroline sheeting and have also had experience with the plastic stuff. Good and bad about both. Plastic can go brittle and I've seen the coroline sag on a roof if it isn't backed with ply or well supported. With regards to weight the coroline is probably heavier but to be honest if the structure can't take that weight then there's something wrong with the summerhouse.
It may just come down to price. In my case it was more a case of choosing the green coroline so the workshop blended in more than shiney plastic.

 

[Ruggers]

It's a good strong frame of 4" x 2" with 12mm ply screwed to it. I'm just wanting to add an additional layer of plastic or bitumen sheet to protect the ply which i've also painted with bitumen. (Belt & braces). These are not visible from the house and garden as they face into a corner.

The plastic is more expensive but comes in longer lengths upto 3m, bitumen is 2m standard. Suppose it won't sag if held vertically agaist ply with plenty of screws or nails

 

[catlad]

I did mine using box steel profile sheets a little more expensive but will last a long time and give it a bit of fire protection.

 

[Ruggers]

I just didnt want to have to start cutting the sheets and having to treat the bare metal edges with galv.

When you nail or screw them are you supposed to use eaves fillers for every row of fixings with the bitumen, or just to close off the top and bottom from drafts? I noticed the PVC ones need support under each row