Any roofing experts here? Can I please pick your brains....

[MikeG.]

It doesn't need to be ply. OSB is much cheaper, and is the standard board used in these circumstances these days.

 

[Kev]

As others have said OSB should be fine. I myself went for plywood as I felt the more uniform finish of plywood would be better for adhering the glue to but have not seen anything to suggest this is the case, just my preference.

 

[Fitzroy]

EPDMed my workshop, my build is documented on here search 6x3 pent shed. My biggest trick would be get a good soft brush and be ready to brush brush brush once laid to get all the bubbles out.

F.

 

[OscarG]

Hi Chaps

Sorry for digging up an old thread but I'm finally getting round to start this EPDM roof and now I'm kind of stuck, so wandered if I can pick your brains.

The roof backs on to the neighbour's roof like this and I don't know how to manage this border between corrugated bitumen and my EPDM.

This is the roof....

The blue line marking roughly the border between the 2 garages. I need to replace the roof to the right of the blue line. You can see my previous failed attempts to stop it leaking!

I've contacted Rubber4Roofs and they think it's going to be very difficult to join the EPDM to the corrugated bitumen. They suggested putting an upstand to separate the 2 roofs then somehow sealing the bitumen against the upstand but I'm not really sure how to do that.

I've made a diagram of what I think he means

Can you think of a way to seal the corrugated against the upstand?

I did ask the neighbour if he'd like to go halves on a big EPDM sheet to cover both roofs with no joins but sadly he didn't fancy it.

If anyone's got any suggestions I'd be most grateful!

 

[MikeG.]

You need a flashing over the corrugated roof, or, indeed, under it, and terminating at the top of the upstand. Then you need to dress your EPDM over the upstand and over the top of that flashing, and down over its face. Given that EPDM won't glue to the flashing, you'll need to fix a piece of timber over the top-most part of the flashing, level with the top of your upstand, and fix your EPDM to that, with their proprietry plastic moulding. You should form a drip of the EPDM by doubling it up, such that water drips off it without getting into contact with your second piece of wood.

 

[Beau]

If you are not committed to re roofing I can recommend an unorthodox way to fix the leaks. Got lots of old corrugated buildings here on the farm and just this summer have been patching a roof that is flatter than that. What I have found works is some stuff called Denzo tape. Funny messy stuff but seems to stick to anything. Lay that over the leaks and apply a coat of bitumen over the top. The roof I have just done sits at such a bad angle the joint of the sheets is in a puddle but it is till dry underneath. Not a purist solution but one that works none the less.

 

[Marineboy]

+1 for Rubber4Roofs. Very quick delivery and they sent way larger piece than I ordered so room to make mistakes in cutting out. But as Mike G says it is seriously heavy, so get help!

 

[OscarG]

You need a flashing over the corrugated roof, or, indeed, under it, and terminating at the top of the upstand. Then you need to dress your EPDM over the upstand and over the top of that flashing, and down over its face. Given that EPDM won't glue to the flashing, you'll need to fix a piece of timber over the top-most part of the flashing, level with the top of your upstand, and fix your EPDM to that, with their proprietry plastic moulding. You should form a drip of the EPDM by doubling it up, such that water drips off it without getting into contact with your second piece of wood.

Thanks Mike.

When you say flashing, do you mean something like this? > https://www.screwfix.com/p/flashband-bo ... 25mm/22704

Sorry, I'm a complete roofing novice!

 

[MikeG.]

I think that the corrugated roof looks like a bitumen-impregnated product such as Onduline. I don't think you'll get anything to stick to that for long. However, they do their own proprietry flashing, which also doubles as a ridge and verge board. You'd have to cut it down to the height of your timber upstand (and the stuff is murder to cut..........it will cost you a saw), but I think it's probably your best bet. You should make that timber upstand as big as you possibly can.........at least 100x50 on edge, and better still if it was 150x50. You'll need to fasten it down very securely.

 

[beech1948]

Just thinking about your neighbour and his lack of agreement to help.

Obviously you should be as helpful and kind to him as possible BUT I think you can just tell him that you are going ahead. That he will need to find a way to seal up his side after you have finished.

If he needs help then provide it but proceed.

 

[OscarG]

I was surprised by neighbour's reluctance as earlier in year he seemed keen to get involved in sharing any roof costs as his roof was leaking a bit. At the time as long as it wasn't crazy money he was onboard. Sadly then we got a huge quote for a felt roof and he got cold feet. Fast forward a few months and he'd get a rubber roof for £300 odd but doesn't fancy it now. Apparently he told my Dad his roof isn't leaking anymore so doesn't feel need to do it.

Shame but I need to tread carefully, he has a good relationship with my folks, I don't wanna screw that up.

Looking at costs a 5.5m x 3m rubber sheet kit for our roof costs £450. A 5.5m x 6m kit big enough for both roofs is about £700. I'm wondering if we should just pay for the lot and offer to do his roof for nothing. For sake of extra £250 might be worth it to avoid aggravation. The extra £250 will be offset by avoiding costs involved with that upstand + flashing etc. I'm still researching Mike's advice.

 

[OscarG]

I think that the corrugated roof looks like a bitumen-impregnated product such as Onduline. I don't think you'll get anything to stick to that for long. However, they do their own proprietry flashing, which also doubles as a ridge and verge board. You'd have to cut it down to the height of your timber upstand (and the stuff is murder to cut..........it will cost you a saw), but I think it's probably your best bet. You should make that timber upstand as big as you possibly can.........at least 100x50 on edge, and better still if it was 150x50. You'll need to fasten it down very securely.

Thanks Mike.

I've had a look on Onduline's site, do you mean use something like this Ridge Unit?

Do you think a 150 x 50 timber upstand secured underneath with some big dirty coachbolts would be strong enough to secure it from a crosswind?

 

[mbartlett99]

Do yourself a favour while you've got the roof off - celotex in between the joists. Its alot easier with no roof there and you'll be glad of come winter.

 

[johnnyb]

I've used rubber loads all from r4r. Initially I used the thick stuff esp on houses but after a few couldn't see the point. I suggest in situations where occasional foot traffic is possible ok. On a normal roof don't bother. Any damage can made good with uncured rubber. This is like a puttyish consistency and as such can be made to go into a corner without major creases if you know how to handle it. It's basically also used for intricate flashing. Think the soft feather edge inner tube patches! The middle of the roof is adhered with rubber latex emulsion and the outside is stuck with contact adhesive.
This is to allow a bit of tension whilst the middle cures.ie the emulsion dries slowly.
The uncured rubber is self adhesive but the rubber sheet needs to be primed using a special product and abraded using a scotchbrite to apply the primer does both( this is because the rubber sheet is talked)
Osb3 is the grade needed. But I prefer ply. I usually nail with stainless ring shank as I can do the whole roof in 5 mins!