Some EPDM Questions

2 Feb 2009
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South Tyneside
United Kingdom
Hi All

I am gradually moving to wards using EPDM for my workshop roof. It's a flat roof (with a slight run-off pitch to it).

Does anyone know :

1. How heavy would a single sheet of EPDM 10mx5m be. Could two of us get it up onto the roof and would it fold up small enough to go in the back of a landrover for transport!

2. The water based adhesive used to bond it - is that just regular builder's PVA adhesive?

Thanks for any help, I'm still learning my way!

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Thanks, hadn't see that one yet;

13 1/2 stone - ooff!

So could two of us lift me onto the roof.

Building it in my head so all we need do is assemble! I'm down to counting screws. The four feet of snow delayed things a bit!

How small would that fold up to?
My sheet was 3.5 X 3.5 and it folded to 18 inches by 12 inches by about 4 inches thick.
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Damn heavy is the answer. I just managed to get a 5x4 sheet up a ladder. This was folded to something like the equivalent of two rolls of felt

As this is a single storey, the best way may be to tie some rope to the bundle and pull it up some sloping timber or some sloping ply sheets

The adhesive is not just PVA, but is a much stronger contact adhesive
I did my roof not long ago (Sept 08) with a EPDM diy kit, great product and would recommend but.... with a word of caution.

Some applications require you fix an edge trim to the gutter edge, mainly for cosmetic features and I agree it looks a lot nicer, but here is where the caution comes in, if you are putting a solid piece of rubber down which is, in itself impregnable to water, why would you then drill fixings through it to hold the trim in place thus creating an element of weakness in said membrane?

Now, I have been told that this should not occur if fitted correctly, well, I would class myself as a competent diyer and fitted the roof exactly as per the instructions with a relative that is also a competent builder. We used a butyl sealing tape which was supplied and a dab of silicone for each fixing.

The problem arose when 6 months later when I ripped out my kitchen ceiling, due to the previous leaking damage, only to find the new osb3 boards underneath damp with water from the gutters edge.

I was also told that this hasn't happened before, well, my point is, unless you rip out the ceiling after the roof is complete and after months of heavy rainfall, how would you ever know? I think most would agree that last years rainfall was exceptional in most places.

My previous felt roof didn't start leaking inside for at least 10 years after I moved in, at which point I noticed there was some collapse of the boards underneath back then, visible from the top, guess the roof was already 10-15 years old prior to that and was just soaking up the water for all that time until it became to much to handle and became saturated. I'm not sure but were EPDM roofs were being fitted 10-15 years ago in this country? So I guess only time will tell.

Maybe I was just unlucky, but, my advice would not to go that route and go for a self attaching trim/fascia that doesn't require drilling. The company I brought my roof from have now adapted this type of fixing (uPVC) so should avoid any problems down the years, although they still supply the fixed trim if you want it.

I did contact a fitter for the said system but he wanted £700, just for fitting the membrane, which was done in a day and to be honest, cannot see him doing any better or different a job. And yes, it did require two people to lift the membrane up onto a single storey roof.

Don't take this the wrong way, even after my ramblings I would still recommend the EPDM route any day. Just don't ruin a perfectly good product by drilling through it.

This is just my personal experience, so not to be taken for granted in any way or form. I have now sealed all the holes with another silicone sealant until I can permanently remove the trim and formflash all the holes properly, surfice to say, no more leaks.
Thanks for the replies, everyone. Twickers, your experiences are useful to hear.

This is for a large workshop with a flat roof, so I was going to simply fold the membrane down over the sides, secure with wooden fascia boards, and pack everything out with silicone.

I may be able to fabricate some sort of drip mechansim under the rear edge, but with a size of membrane I'll be using, doing hidden fold-unders all the way around won't really be practical, I need to keep it manageable.
I've just recently put a 7m x 6.5m membrane on my garage roof. My strapping son and I could only just lift it between the two of us. I did consider pulling it up a couple of scaffold boards but fortunately I've a tractor with a bucket on it and so was able to "pop" it up there.

Surprisingly easy to move it about once opened out flat.

Twickers' comments about the gutter trim has got me thinking, though.

The method I used was to fix a small EDPM strip with staples that hangs down into the gutter, then a 2 foot wide strip that is fixed to a batten against the barge board and then folded up and over and was glued to the roof deck. then the main EPDM sheet is then bonded over this up to the gutter edge.

Because of this fold over technique there are no holes through into the batten and the gutter edge is completely watertight. The down side is, as I explained, the raising of the gutter edge by 5mm.

Been chucking it down to day and all seems fine up there. :D :D
good thinking per spec to the torch on method. :D

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