Polycarbonate sheet on pergola

[Tigercubrider]

From memory, it was the top surface.
I guess it doesn’t matter but when installing, you need to peel the film off the edge by 25/35mm to clear the joining strips.

 

[mderoy]

So the edge strips I will prefit before putting the sheet on the rafters. But wanted to ask what for tips on how to actually screw it down onto the rafters since the sheet cannot be stepped on. I read some places that putting a plank of wood or something like a deck board to distribute the weight so it’s not concentrated to one area will help. Any suggestions?

 

[Tigercubrider]

I am assuming that you have rafters running front to back?
Probably at 10° or more fall for rain to drain?

Either start in the middle or go side to side, keep your weight on a ladder.
I have stood on poly wall but only where rafters are

 

[mderoy]

I am assuming that you have rafters running front to back?
Probably at 10° or more fall for rain to drain?

Either start in the middle or go side to side, keep your weight on a ladder.
I have stood on poly wall but only where rafters are

Correct the rafters are coming from back to front but since my pergola is right next to my lean-to conservatory which has a roof and gutter I’ve made the fall to go towards the back as the rafters sit slight higher than the conservatory glass roof so the polycarbonate sheet will essentially drain down onto the glass then flow onto the existing gutting. This hopefully will help keep my gutter clear of things flying into it too since the polycarbonate sheet will provide a cover for it.

So generally if I stand on the sheet on the rafters it should be ok? But to play it safe can just put a board across supported by rafters then step on the board? But even then ideally step on the board where the rafters are running back to front?

 

[Tigercubrider]

Theoretically, yes.
But avoid full weight as much as possible. Always rely on woodwork, not plastic to support weight.

 

[mderoy]

Finally received the button to install the sheet. The plastic shank bit that goes into the drilled hole is just under 10mm (9.7mm) and the polycarbonate sheet says to make sure screw hole is 50% larger for thermal expansion. So should I drill a 15mm hole for each button?