90 degree joint for lean-to roof joist

[XTiffy]

The caps came without nails or screws. I chose to use green outdoor screws which are available in various lengths. The caps are in two parts held together with a small plastic extrusion (so caps do not get lost,) this is helpful as sometimes in the summer the cap can pop up with expansion.
I used a regular HSS drill but that idea of a masonary bit must have been meant for concrete sheets, for plastic sheets the wood bits would be ok.

 

[Chris152]

The caps came without nails or screws. I chose to use green outdoor screws which are available in various lengths. The caps are in two parts held together with a small plastic extrusion (so caps do not get lost,) this is helpful as sometimes in the summer the cap can pop up with expansion.
I used a regular HSS drill but that idea of a masonary bit must have been meant for concrete sheets, for plastic sheets the wood bits would be ok.

OK, that's great - thank you!

 

[XTiffy]

Chris 152,
I can't emphasize enough not to wind screws in too far, with plastic or unduline sheets it is easy to flatten or spread the sheet which messes up the meshing of adjacent sheets. As the screws go in at the crest, rain immediately flows down into the valleys, so a small"pinch" is all you need.

 

[Fergie 307]

I use these from seller eighty-twenty on e bay. They take size 8/10 screws. I much prefer using screws rather than nails especially on the clear sheets, they are quite brittle.

 

[trvlr]

Onduline have excellent tutorials re' fixing all manner of roofing materials; as does Aerialplastics.

https://www.ondulineshop.com

https://www.arielplastics.com

And there are excellent youtube vidoes re' the assorted systems; especially corrugated bitumen (some have been referenced by others on this forum).

If in doubt... no harm to add an additional support running the length/width(?) of the area to be covered by whichever material? Would help reduce any tendancy for sagging regardless of pitch of roof.

Width of roof for me (in the above offerng) is the measurement from one end to the other; length is the measurement from apex to guttering (if present).

 

[Fergie 307]

Main thing is to always start from the end of the roof furthest away from the prevailing wind direction, and work towards it. That way the wind will blow over your joints rather than into them. And stick to whatever recommendations the manufacturer has about overlaps.