EPDM rubber roofing

[Astrokev]

Hi All

Just about to order some EPDM for my obsy roof.

Folks say it is easy to fit using adhesive, but does this stick effectively to wood that has been treated with a solvent based preservative?

I'm keen to paint preserver on the exposed timber, but obviously won't do this if the EPDM will not stick to this!

Also, please could anyone recommend what grade / thickness of EPDM I should go for?

Many thanks

kev

[Craney]

Hi Kev,  I replaced a flat felt roof on my brick out-houses a few years ago.   Yes, easy to fit.  Allow for a generous overlap and then trim to size with stanley knife.

I fitted it over OSB3 panels which must have some form of humidity/moisture protection using the recommended adhesive with no problems.  To be sure, best to cut a sample strip and replicate the bond to a similar (small) piece of wood / preservative combo.   I went for the full thickness industrial strength stuff (   1.5mm or maybe more )   as I might be using ladders on it in the future. Maybe overkill for an obsy ??  Thinner grade means it will be cheaper and lighter.  Mine was a bit of a beast to get onto the roof and then manouvre around so it was square etc.... the company that supplied mine had made the required area from smaller strips glued together, not an issue in terms of performance but it might upset your aesthetics etc...   The job itself does need thinking about beforehand as I recall there are two adhesives to put down ( primer and then the bonding agent ) and you have a limited time to get things in place before it cures. (5-10 minutes as opposed to seconds ).

 Mine looked OK when done, but developed small ridge blisters over the points where the OSB panels butted together even though I had taped them over beforehand to make them as flat as possible.  Again these do not create any real problems apart from rainwater begins to pool a bit before running off.

Hope this helps.

 

Sean.

 

[Bizibilder]

I used "shed" grade EDPM and it did the job well.  It is now four winters old and is 100% waterproof.  It is heavy, so really a two person install is easier - especially lifting it onto the roof.  The glue I used resembled thick treacle but worked well - I think it was water based as it had no discernible odour.  Mine was bonded directly onto plywood.  The only issue was a black mold of some sort on the underside of the ply after the first winter.  A liberal coating of anti-fungal paint has stopped that in its tracks.

[Davey-T]

Made my large, 3000gal pond, with it 30 years ago and it's still going strong

Dave

[Astrokev]

19 hours ago, Craney said:

Hi Kev,  I replaced a flat felt roof on my brick out-houses a few years ago.   Yes, easy to fit.  Allow for a generous overlap and then trim to size with stanley knife.

I fitted it over OSB3 panels which must have some form of humidity/moisture protection using the recommended adhesive with no problems.  To be sure, best to cut a sample strip and replicate the bond to a similar (small) piece of wood / preservative combo.   I went for the full thickness industrial strength stuff (   1.5mm or maybe more )   as I might be using ladders on it in the future. Maybe overkill for an obsy ??  Thinner grade means it will be cheaper and lighter.  Mine was a bit of a beast to get onto the roof and then manouvre around so it was square etc.... the company that supplied mine had made the required area from smaller strips glued together, not an issue in terms of performance but it might upset your aesthetics etc...   The job itself does need thinking about beforehand as I recall there are two adhesives to put down ( primer and then the bonding agent ) and you have a limited time to get things in place before it cures. (5-10 minutes as opposed to seconds ).

 Mine looked OK when done, but developed small ridge blisters over the points where the OSB panels butted together even though I had taped them over beforehand to make them as flat as possible.  Again these do not create any real problems apart from rainwater begins to pool a bit before running off.

Hope this helps.

 

Sean.

 

Thanks Sean, that's really helpful

[Astrokev]

3 hours ago, Bizibilder said:

I used "shed" grade EDPM and it did the job well.  It is now four winters old and is 100% waterproof.  It is heavy, so really a two person install is easier - especially lifting it onto the roof.  The glue I used resembled thick treacle but worked well - I think it was water based as it had no discernible odour.  Mine was bonded directly onto plywood.  The only issue was a black mold of some sort on the underside of the ply after the first winter.  A liberal coating of anti-fungal paint has stopped that in its tracks.

Thanks Roger - great advice.

[RayD]

I ordered the garden building kit as I wanted all the edge trims and drip edges.  I think the 1.2mm is standard and it is perfect for an obsy.

The adhesive gets applied in 2 elements.  You have a lowish tack bond which gets applied to the centre section, and this allows a tiny bit of movement so you can roll or brush the rubber flat.  You then apply a high tack contact adhesive to the outer edges (about 150mm all the way round) which prevents any roll up etc.  If you get the kit from R4R it comes with instructions anyway.

If you have a roof which you feel may cause issues then they also do a primer which you can apply first, but I wouldn't think a preservative treatment is going to need the primer, but there if you feel the need.

As with all the bits so far, Kev, take your time with it, decide how you want it to look after (do you want the kit with the trims etc.) and it will make a great topping off of a really nice build to date.

[Astrokev]

2 hours ago, RayD said:

As with all the bits so far, Kev, take your time with it, decide how you want it to look after (do you want the kit with the trims etc.) and it will make a great topping off of a really nice build to date.

Thanks Ray. Just spent a few hours checking my design to calculate what I need and think I've finally got it sorted. Quite expensive stuff, but over the long term I'm sure this is worth it. Just want to measure the actual obsy tomorrow to make sure my drawings are correct. Paranoid - who, me ? ?

[Davey-T]

15 minutes ago, Astrokev said:

Just want to measure the actual obsy tomorrow to make sure my drawings are correct. Paranoid - who, me ?

As we always say when estimating materials, better to be looking at it than for it 

Dave

[RayD]

Yes not cheap at all, Kev, but well worth it. Pretty much there for the life of the obsy.

[mikeDnight]

After my plastic roof was torn off in a storm a couple of years ago, I replaced it with a ply roof covered  with rubber sheeting. Once glued to the ply using the adhesive supplied from the builders merchants, the rubber sheet is there to stay. I then trimmed the overlap which acts as a great weather proof skirt, clad the edges with plastic cladding and fit a gutter to catch any runoff, and to give the building a tidyish appearance.

 

[Gina]

Rubber4Roofs shed kit of the appropriate size is what I used for my observatory 4 or 5 years ago - perfect ?

Yes, quite heavy but I got it up onto the roof and glued it on by myself.  One piece for the ROR and another for the warm room.