EPDM Roofing a puncture resistance

[Dan Mages]

Its time for a new roof for our new house. We have a low pitch roof over the screened in porch that gives me a little heartburn. The decent quotes that I have received are for asphalt roll roofing over that portion of the roof. I would prefer to use EPDM due to its durability and potential to cover this porch in one solid piece of roofing. When I asked about it as an option, I was told by one roofer that it is too puncture prone and that the trees in my back yard pose too much of a risk. Any roofers here? Is this a real concern, or is he just fishing for long term business maintaining that portion of the roof?

Thanks,

Dan

[Bob Lloyd]

How far are the trees from the roof and how big are they? Small branches should not be an issue. One other option would be to cover the whole roof with ice and water shield and shingle it.

[Brian Effinger]

Dan, EPDM is used extensively on commercial structures, and I have specified it many times, with no problems being reported after installation. One thing to consider is putting down rigid insulation first and then the membrane. It is done that way on these buildings for the insulating factor, but I would also think that the insulation would help with anything falling on it because it has a little "give".
Bob also gave another good suggestion - full ice & water shield and then shingles. I have seen this done on some houses with low pitched roofs, and it seems to work well. Of course I haven't seen how these work in the long term (20 years) yet. Maybe only 5 or so.
What is the pitch of your roof anyway?

[Dan Mages]

I don't know the exact pitch, but here is a picture of the roof.
http://img.photobucket.com/albums/v647/DanMages/101_0006.jpg

Dan

[Bob Lloyd]

Dan
It is hard to tell how far away the trees are. Are the branches overhanging or close to it? As mentioned earlier, the small branches should not be an issue if one were to break off and land on it. If there is a small puncture, EPDM roofs are easily repaired anyway. About 10 years ago I did a fairly flat roof covering all of it with ice and water shield and then roof shingles. Have not heard of any problems. It was a little like yours where it could be seen from a second story window and they did not want to look at rolled roofing. About 10 years is the advertised lifespan of rolled roofing anyway.

[David G Baker]

I have an attachment to my old farm house that had pretty much the same pitch as your enclosed porch. When I had my roof redone on my house I had the roofers raise the pitch of the add on. It was not that expensive because of the roof being removed on the main house. The roof of the main structure had to have everything removed right down to the trusses due to poor ventilation so it was easy to raise the add on's roof, they added new 2x8s that married to the main structure, added sheeting and roofing material. Cost me about $1000 extra.

[Jim Mattheiss]

Dan:

I took a look at the picture of your roof and thought you had bought my first house. :eek:

The pitch on my roof was 4 1/2 on 12 and the inspector required roll roofing. We went with rubber membrane and as far as I know it's still fine 15 years later.

Cheers

Jim

[Brian Effinger]

I don't know the exact pitch, but here is a picture of the roof.

Dan, that looks like a 2 : 12 pitch. I also assume that you are re-roofing the entire house? In that case, I think Bob's suggestion of ice & water shield with shingles would work. This looks like an unheated sunroom, so the low pitch is less of a concern to me. How far does the main roof overhang the outside wall? The ice & water shield should extend back up the roof 2 feet from the interior side of the exterior wall. I would also extend it up at least 2 feet (if not 3) from the juncture between the sunroom roof and main roof.

Also, if they are replacing all of the aluminum trim, have them remove it from the sunroom wall and run the ice & water shield from the main roof up onto the little bit of sunroom wall next to it - it will act as flashing.

One more thing. It looks like something funky is going on with the edge of the main roof. First, the shingles should overlap the aluminum drip edge and overhang the edge slightly. Make sure the roofers do that. Secondly it looks like the roof is buckled in the last 3 courses of shingles. I'd definitely have them look into that. Maybe some of the roof sheathing is coming up or rotting away, which would lead me to believe that ice is building up at that point and getting under the shingles, because of the mis-installed drip edge, and the lack of ice & water shield. Is "mis-installed" even a word? I guess it is now.

[Brian Effinger]

Wow, Jim. I can't believe that a building inspector would want rolled roofing on a 4-1/2 : 12 pitch. :eek: Regular asphalt shingles will work very well down to a 4 : 12, and the various manufacturers claim it will work down to a 3 : 12. This hack sounds like he's was trained by the inspectors in a certain town near me.

[Dan Mages]

Dan, that looks like a 2 : 12 pitch. I also assume that you are re-roofing the entire house? In that case, I think Bob's suggestion of ice & water shield with shingles would work. This looks like an unheated sunroom, so the low pitch is less of a concern to me. How far does the main roof overhang the outside wall? The ice & water shield should extend back up the roof 2 feet from the interior side of the exterior wall. I would also extend it up at least 2 feet (if not 3) from the juncture between the sunroom roof and main roof.

Also, if they are replacing all of the aluminum trim, have them remove it from the sunroom wall and run the ice & water shield from the main roof up onto the little bit of sunroom wall next to it - it will act as flashing.

One more thing. It looks like something funky is going on with the edge of the main roof. First, the shingles should overlap the aluminum drip edge and overhang the edge slightly. Make sure the roofers do that. Secondly it looks like the roof is buckled in the last 3 courses of shingles. I'd definitely have them look into that. Maybe some of the roof sheathing is coming up or rotting away, which would lead me to believe that ice is building up at that point and getting under the shingles, because of the mis-installed drip edge, and the lack of ice & water shield. Is "mis-installed" even a word? I guess it is now.

Thanks for all of the detail and input. I will definately have those details checked out. The funky thing I think you see at the edge of the main roof is an old attempt at a clog free gutter system. I think we may be in for new gutters as well as I know that some of these overflow with major rain falls.

Per other questions regarding trees and heights. There are a few 20-30ft mature trees in my backyard and in neighboring yards that may pose a risk.

Dan

Dan

[Craig Coney]

Dan,
If you are concearned about small punctures on EPDM, you could add a second layer of EPDM material on top. I have used this before and it has worked well in high abuse areas.

Also, look at the mil thickness of the membrane. That will affect how well it will hold up to debris falling on the roof.

[Jim Mattheiss]

Brian:

Your probably right about the pitch being ok for shingles, but he's the inspector. :confused: You can fight 'em but you won't necessarily beat 'em.

Jim

[Josh Davis]

One other product to consider is a pvc based flat roof product. Similar to epdm, but usually tougher. One product I have used before is DuroLast. Its going to be more expensive than rubber. The trade off is its a lot stronger. Rubber is just that, a thing sheet of epdm. A pvc based roofing product usually has a nylon mesh at the heart of the system, either side is coated in pvc. It will stand up better to branch hits. Its as easy to repair as epdm, you can use pvc glue to glue a patch, or you can use a heat gun to melt the patch to the roof.

[Brian Effinger]

Brian:

Your probably right about the pitch being ok for shingles, but he's the inspector. :confused: You can fight 'em but you won't necessarily beat 'em.

Jim
As an architect, I've learned that one. Of course, now they don't like it when I agree with them either. The latest example is a steel beam I sized for a garage addition I designed. It will be holding up a second floor and ceiling, but no roof. The building inspector said that his computer told him that the beam would not work and it just had to be a few sizes larger. The cost of the larger beam wasn't that much, so I wrote a letter that said I take no exceptions to the larger beam. He told the contractor that he didn't like my attitude because I didn't admit I was wrong! It took a lot of strength not to march down there with my structural calculations and shove them up his you know what. Some of these inspectors are on such a power trip it is unbelievable.

Sorry for the rant, but these types of guys just really get to me.