What adhesive for epdm shed roof
Discussion
andy43 said:
From memory there are two types of proper adhesive - water and solvent based which is supposed to be just for the edges - I used the solvent based stuff all over, no problems maybe ten years later.
This, the water based one isn't particularly strong, but enough to hold it in place and allows a bit of movement whilst you get rid of air bubbles etc.The solvent one for the edges is a contact adhesive (ie coat both surfaces) and goes off very quickly and there's little budging it once it has. If you've got an edge exposed to wind make sure you get this bit right (don't ask!).
I'm impressed you managed to do a whole roof with the solvent stuff given how much of a pig it is to work with!
My shed may have bubbles 
Also used the steel trims round the eaves which helps hold it in place.
I’ve also done an entire patio over a habitable room with the thicker Epdm floating on an underlay with slabs and pave pads sat on it. Lapped up the walls, corners folded, solvent adhesive all round with ally flashings over the edges and sealed into mortar joints with silicone. Zero problems in years.
Also used the steel trims round the eaves which helps hold it in place.
I’ve also done an entire patio over a habitable room with the thicker Epdm floating on an underlay with slabs and pave pads sat on it. Lapped up the walls, corners folded, solvent adhesive all round with ally flashings over the edges and sealed into mortar joints with silicone. Zero problems in years.
The Gauge said:
What's the best thickness for a shed roof? I was thinking of going with this 1.5mm bundle that comes with both types of adhesive for my new shed roof.
Depends what kind of shed. I'd probably just go with the 1.2mm personally for a shed. https://www.rubber4roofs.co.uk/blog/which-thicknes...
Disclaimer: I'm not an expert, I'd just recently been looking at this stuff!
I used the thinner stuff on my shed. Don’t underestimate the weight difference if you’re diy-ing by yourself!
Had a dormer professionally reroofed by a Firestone approved trainer and he was confident the thinner weight is absolutely fine.
I used 1.5 under our patio - beam and block with rooms underneath, screed, fleece, EPDM and then slabs on pave pad plastic feet. The 1.5 is proper tough, not sure it’s needed on a roof though.
Had a dormer professionally reroofed by a Firestone approved trainer and he was confident the thinner weight is absolutely fine.
I used 1.5 under our patio - beam and block with rooms underneath, screed, fleece, EPDM and then slabs on pave pad plastic feet. The 1.5 is proper tough, not sure it’s needed on a roof though.
grumbas said:
andy43 said:
From memory there are two types of proper adhesive - water and solvent based which is supposed to be just for the edges - I used the solvent based stuff all over, no problems maybe ten years later.
This, the water based one isn't particularly strong, but enough to hold it in place and allows a bit of movement whilst you get rid of air bubbles etc.The solvent one for the edges is a contact adhesive (ie coat both surfaces) and goes off very quickly and there's little budging it once it has. If you've got an edge exposed to wind make sure you get this bit right (don't ask!).
I'm impressed you managed to do a whole roof with the solvent stuff given how much of a pig it is to work with!
andy43 said:
My shed may have bubbles
I also did my whole shed roof with the solvent stuff, which as has been mentioned is more of a contact adhesive. Whilst not the easiest thing to work with, it wasn't too bad - just a case of starting at one end, then putting the adhesive on a strip around a foot wide on the membrane and shed roof, then rolling it down to get rid of bubbles. Rinse and repeat until the roof was completed.I used the solvent stuff as it is stronger, so thought over-engineering it would ensure no issues with the EPDM coming loose in future, as opposed to using the solvent stuff round the edges and the water based stuff for the majority of the area (as recommended by the suppliers).
When done, it all looked fine with no bubbles.
As it's right down the end of a long garden with trees between it and the house, and I'd done it in winter, I didn't have cause to go down there for a few weeks, so when I did go and check it some time later, the roof was covered in small bubbles. I can only presume that this was due to gases being given off as the adhesive cured over time, as mentioned by someone on this thread.
Fortunately, as it's out of sight behind bushes and trees, I really don't care what it looks like. The important thing is that the EPDM is stuck down, and the roof is waterproof. Despite the bubbles, the EPDM is stuck down very well, and there's no chance of it coming loose - it's already gone through several storms with very strong winds (60MPH+), so I'm happy with the result.
If the shed was closer to the house and in view daily, I'd be pretty annoyed with the result as it would bug me every time I looked at it.
TL:DR You're probably better off following the supplier's advice and using water based adhesive for the majority of the area, and the solvent based contact adhesive all round the edges to really ensure they do not lift in the wind.
Aluminati said:
The thing to watch with solvents, is the gassing and ensuing blisters that will occur.
That’ll be where my bubbles came from I remember coming back to it the day after and wondering why it’d got measles. Still there, still perfectly waterproof, unlike the crappy felt that was on it before. It’s good stuff but I’ve never heard of the off gassing before. Noted!Mine will be just an 8x6 or 7x5 garden shed positioned close to the garden boundary, the pent roof will be angled towards my neighbour so I wont see it, but I'm conscious of not displaying an unsightly roof to my neighbour.
So when using either solvent or water based adhesives, how easy or difficult would it be to strip the rubber off in years to come when it needs redoing? Or would you just apply another sheet over the top? Do the adhesives even work for rubber on rubber?
So when using either solvent or water based adhesives, how easy or difficult would it be to strip the rubber off in years to come when it needs redoing? Or would you just apply another sheet over the top? Do the adhesives even work for rubber on rubber?
The Gauge said:
Mine will be just an 8x6 or 7x5 garden shed positioned close to the garden boundary, the pent roof will be angled towards my neighbour so I wont see it, but I'm conscious of not displaying an unsightly roof to my neighbour.
So when using either solvent or water based adhesives, how easy or difficult would it be to strip the rubber off in years to come when it needs redoing? Or would you just apply another sheet over the top? Do the adhesives even work for rubber on rubber?
I'd imagine the adhesives to be very effective sticking rubber to rubber, but the issue with the solvent based ones causing bubbles (as mentioned above) would likely be exascerbated as both surfaces would be non-permeable.So when using either solvent or water based adhesives, how easy or difficult would it be to strip the rubber off in years to come when it needs redoing? Or would you just apply another sheet over the top? Do the adhesives even work for rubber on rubber?
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