Fitting bitumen shingles

[PeteWilliams]

I was planning on doing my shed roof with these bitumen shingles:
https://www.aboutroofing.com/ars-he...gles-3-square-metre-pack-black-green-red.html

Have watched a few installation videos, but there's a couple things I'm not sure about…

1 - Should I use a breathable membrane between the shingles and OSB? I should have enough left over from the walls to do the roof, but not sure if it helps - the videos I saw don't seem to use them

2 - If no to the membrane, do I need an underlay? The product info suggests it's optional.

3 - Do you need adhesive to stick them on? Some of the shingles I've seen have a self-adhesive backing but the one my supplier sells don't. I've seen in some videos, even without the self-adhesive, they seem to just nail them on, but I'd imagine the wind could lift them. Also wondering if having the breathable membrane would make this worse as the shingles wouldn't be stuck directly to the OSB.

4 - What do you do at the edges? With a felt roof you'd normally bend them over the edge and nail a strip of wood over it, but in most of the videos I've seen they cut them flush and use an aluminium drip edge - though this seems to be an American thing. Any suggestions?

Cheers

Pete

 

[Scarlet Pimpernel]

1. No, not a breathable membrane.
2. Yes, an underlay.
3. If they have adhesive, the sun will melt it and 'activate' it. If no adhesive present, I'd use it at edges and other exposed situations.
4. There are plastic cappings you could use, but they tend to be white or brown. You could cut them flush and use adhesive and nails. Or warm up the tile and bend it over the edge. Trim it as appropriate.

 

[^woody^]

I did the kid's playhouse in these back in the day - just nailed them to the timber roof boards. That's it. Timber barge board.

 

[PeteWilliams]

Thanks both current thinking it to go with a felt underlay.
I presume I can staple that on seeing as it'll effectively be nailed on when the shingles go on?
If I'm using a felt underlay, I could fold and nail them at the edges as per a standard roof and then have the shingles flush to the edge.

Any reason not to do this?