How should I attach epdm rubber roofing to my wood shed roof?

[jeffesonm]

I'm making a wood shed and have some large pieces of epdm I'd like to use for the roof. I will have standard rafters covered with OSB and then epdm. How should I attach the epdm to the osb? It seems like for real roofs they glue it down using adhesive, but not sure I want to do that.... seems like a mess if I ever need to replace it. The rubber roofing material covering my stacks is held on just fine with a few splits. I'm thinking if I just mechanically fasten it around the edge it should be fine. Thoughts?

 

[ironpony]

put down a layer of foam board to protect the rubber from nail pops, them attach the perimeter on the fascia board.

 

[DougA]

I have EPDM on my flat roof section of my house and it is attached with contact cement. For smaller areas like you have, nailing the edges is just as good. You shouldn't need to use a foam board layer to protect it from nail pops, but an old bed sheet, carpets or newspapers is used to protect EPDM from stones when you use it for lining a pond, so it wouldn't do any harm either. It's incredibly durable stuff.

 

[bags]

EPDM is applied with a body bonding adhesive. You can glue any seams with lap adhesive and lap caulk the very edge. EPDM can be glued to black insul board, roofing foam insulation board, OR directly to OSB or plywood. No need for sheets, blankets, or anything. In fact for you application just put the EPDM directly onto the OSB.

Get a hammer and just set the nails holding on the OSB. Just smack them down and make sure they are not sticking up. I would not be very concerned with nail pops at all. EPDM comes in different thicknesses also. 6 or 4 mil. 4 being slightly thinner but still very durable.

I'm a contractor and have done many rubber roofs over the years.

There are mechanical ways to fasten EPDM too. Go to a place that sells EPDM and get termination bar. It is an aluminum bar of flat stock about 1" inch X 1/8" to 3/16" thick and 10 to 12 feet long. It has holes every 12 to 16 inches or so for screws to fasten thru and secure the rubber. Termination bar is fairly inexpensive as are the screws.

Do you have one piece of rubber that covers the entire roof? Is the roof a gable, shed roof, or what? Say if you have a gable and two pieces of EPDM one for each side then you need to fasten the edges and the peak. If it's just a no frills wood shed I wouldn't get too carried away. You mainly just need to secure it enough so the wind doesn't blow it off. With termination bars removal is easy but rubber roofs last a long time. I put one on one of my buildings back in 1994 and it still looks almost new. Never an issue.

Another cheap option would be to get pressure treated 1 X 2's and just screw those down with exterior coated screws. Not sure how elaborate you want to get or how nice it needs to look. I glue all of mine but have used termination bars a couple of times in certain conditions. Now they even have a lap tape to use instead of lap adhesive. Much easier to work with than the spread on glues. Google ways to fasten EPDM or look on Youtube. I'm sure there will be tons of info and tutorials etc;

 

[jeffesonm]

Thanks for all the info... it is a shed roof. I think I'm going to sandwich it in between the sub-fascia and fascia boards and screw it all together. I have 2, maybe three pieces to join so I was going to overlap the top one above the bottom and then join them together using some double sided tape made for epdm pond liners.

 

[bags]

You will be fine for a wood shed. Ideally EPDM does get insulation board beneath it like IronPony mentions and glued down. The roof will probably last longer with this type of install and it is just a better application all the way around.

 

[Hogwildz]

Screw the OSB down, then no worries about nail pops.
If you leave an overhang of OSB around all 4 sides, you can then wrap the EPDM around and inwards and sandwich it underneath the overhang more, less chance of water running behind the fascia board, and more water dripping off the edges.

 

[bags]

Yeah, the rubber wedged between boards is a not so great detail. They also make a drip edge you could put down and cover the fascia and then glue or fasten to that instead. Sounds like he might already have the OSB nailed. Not sure. Screws are almost always better in many situations except where you need sheer strength.

 

[jeffesonm]

Yes OSB is already nailed down using a nail gun. Any that were poking out I gave a few extra whacks with the hammer. They are ring shank so hopefully they'll stay put.

I considered termination bar for the edge but it's more than I want to spend. I got the OSB for free and the rubber roofing for $3/piece. I was going to wrap the epdm all the way around and back under the sub-fascia and then use pressure treated 2x for the fascia. I figure maybe a little water would get behind the PT fascia and eventually rot it away, but it would take awhile. If I was ambitious I could bevel the top of fascia to try and shed water better, or run a bead of caulk between the board and the rubber.

Open to other [cheap] edge detail ideas as well.

 

[bags]

If you have enough rubber you could just go over the outside fascia board and neatly wrap it with rubber. Depends on what look you are after for the finished product. Do you have a table saw or access to one? If so you could spring a little cash for a plastic board like Azek or similar. Say a 1 X 6 and make rippers then drill it and run screws thru it to fasten the rubber to the fascia. Maybe make the rippers one inch and you could get 5 pieces out of a 10 footer therefore giving you 50 lineal feet of coverage out of one Azek 1 X 6 board. That will not rot.

You could fasten them towards the bottom of the fascia and bevel the top edge on a 45 degree leaving about 1/4" of flat at the top for caulk and then lap caulk where the ripper meets the rubber. It would serve as a drip edge type deal too. There are many options if you get creative. Cheap promotes creativity.

 

[Highbeam]

EPDM comes in different thicknesses also. 6 or 4 mil. 4 being slightly thinner but still very durable.

Really? 6mil. The PE vapor barrier that I put under my house an concrete is only 6 mil thick (that's 6 thousandths of an inch I think). Do you mean 60 mil?

 

[DougA]

It's either 45 or 60. I used 45 on my roof and it has a 50 yr warranty. So far, we're at 32 yrs and the only problems have been at places where pipes come through the roof. In the time, I'm now on my second set of shingles for the sloped part.

 

[bags]

Yes, High Beam you are correct. The lingo in the roofing world is 4 or 6 for short. Sorry for any confusion. For an example when ordering some the dude on the phone or behind the counter asks if you want 4 or 6 mil. Just an abbreviation of sorts. EPDM is not thin like 6 mil plastic sheets. EPDM is good stuff and lasts a very long time if properly installed.

 

[Hogwildz]

I roofed for 13 years, and never used that lingo.
Every roofer & supply house I ever known called it what it was 060 or 045.
On top of that you would ask for reinforced or non-reinforced.
Maybe a geographical difference thing.

DougA, the membrane itself will last forever. The flashings are what will fail in time, as they are installed in an uncured form, and made of different properties. They used to use cured & uncured neoprene flashing, which had about a 10-15 yr life span. Glue seams where the second area to fail, and very dependent of the knowledge, skill and application of the person installing the roof. The main field rubber will outlast us all, aside from being penetrated by anything.