Fitting and finishing EPDM roof now, and fitting a skylight later (thoughts)

[WoOt]

I'm about to fit the roof to the new extension, and was hoping to finish it with EPDM as that looks like a fairly DIY friendly solution.

But with costs creeping up, and the sunny season now solidly behind us. I just want to get it ready for winter.

I've been playing with the idea of doing the roof with all supports in place for the rooflight, but without fitting the upstand and just putting a sheet of OSB in place for now.

This would mean the roof installation will be far easier as I just have to glue EPDM to a flat rectangle. Which in turn would mean it will be done faster - and cheaper as I wouldn't have to order the rooflight yet.

At the same time, I realise I'll have to then come back to this job in spring. But that's a problem for future me.

Am I mad for considering this? Or would it be rather easy to retrofit the rooflight next spring, as long as all the joists and supports are already in place? I was thinking I'd glue the whole roof and maybe not glue the rectangle where the rooflight will be.

 

[RandomGrinch]

Hi,

I'm just a DIY'er, so feel free to ignore
I believe with the way edpm is laid, it may be easier to insert the upstand afterwards, anyway.
Videos such as:

Show a cross being cut in the membrane; the segments are adhered to the rooflight and the corners are then flashed.

So, no you are not mad to consider this!
And here's a link, just to prove others do the same!:

https://www.avenirroofing.co.uk/blog/how-to-fit-a-skylight-in-a-firestone-epdm-flat-roof/

If the area for the rooflight is small, and you will definitely fit it sometime soon, you could also leave the adhesive off of that area; making the peeling back of the membrane a lot simpler for future you!

 

[thomp1983]

We built the upstand and the roofer laid the epdm up and onto the top edges, we then just put a cut to size board over the hole weighed down with some bricks, been like that a couple of months with no issues whilst we wait for our roof lantern to be fitted.

 

[WoOt]

How did you measure where to cut? 'cause part of the appeal of it is being able to lay the sheet on a flat surface, rather than figuring out where to cut the EPDM (and the worry of cutting it in the wrong place.

 

[thomp1983]

Our roof lantern had an installation guide stating the size of openings required, I'd imagine that's fairly standard

 

[catlad]

Board it over then drill a hole in each corner, you can then mark it with a pencil for your opening, get some scrap timber and screw it internally around the inside of your skylight opening. You can now go outside and cut the opening for the skylight without the timber falling through. ( circular saw ) Don't glue the bit where the skylights will be when you put your rubber down, that way in spring
you can just unscrew the scraps of timber from the inside and take the boards out ready for fitting the skylights.