I saw this new EPDM installation today. Does this look like a problem area? Did they not have enough adhesive or was the application just sloppy?
Also, is there a better way to handle this transition?
As far as I know, there are no problems with this roof (i.e. leaks), but I wondered if it was done well or not.
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Replies
The third picture shows really sloppy installation. Could be the glue was not compatible. I have had glue from suppliers that caused all sorts of wrinkles. It does not appear that any isolation is there between the shingles and the rubber. They are not compatible with each other. The solvents in the asphalt shingles can cause the rubber to deteriorate. Is the rubber roof a flat roof?
Is there a better way to handle this transition?
As mentioned, asphalt shingles and EPDM don't like each other. The lowest course of shingles should terminate over a metal flashing which in turn laps over the EPDM. As a remedial solution to the existing situation, I'd say strip the bottom two courses of shingles and slide in a good 24" of galvy.
Dinosaur
How now, Mighty Sauron, that thou art not broughtlow by this? For thine evil pales before that whichfoolish men call Justice....
I've seen 20 y/o epdm under 20 y/o shingles. Looked like they were getting along OK to me. Both old and ready to retire.
Using a liquid asphalt product on epdm will cause some heartache, but there's about 89,450,264 installtions done as pictured and I've never gotten a service call because of incompatibility issues with shingles lapped over epdm. http://www.quittintime.com/ View Image
That's interesting, Grant. I'm just going 'by the book', of course. There aren't a lotta residential flat roofs up here (can u say 'Snow Load'?) so I don't see that many of them. You've seen at least 89,450,262 more....
OTOH, even if the shingles won't eat the rubber, I still think the transition would look better with some metal in there.
Dinosaur
How now, Mighty Sauron, that thou art not broughtlow by this? For thine evil pales before that whichfoolish men call Justice....
I still think the transition would look better with some metal in there.
I don't disagree. But that's one of those situations you can usually only see by standing on the roof.http://www.quittintime.com/ View Image
Which means that by the time the HO sees it, it's leaking or he wouldn't be up there....
Dinosaur
How now, Mighty Sauron, that thou art not broughtlow by this? For thine evil pales before that whichfoolish men call Justice....
" I still think the transition would look better with some metal in there."There's about three ways to handle that, none of them righter or wronger than the ohter
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I often see 'em bubble like that until the glue is completely cured. Happens more in the winter. Look at it again in a week. If there's still bubbles, then there's a glue problem.
Looks like that "catwalk" isn't finished yet.
http://www.quittintime.com/ View Image
Grant,I will take a look at the roof again in a while too see if it's has laid down any since the photo was taken.When you say "catwalk", what do you mean? Are you referring to the area where the second sheet laps over the first?
Jon Blakemore RappahannockINC.com Fredericksburg, VA
Looks like rubber was laid down before the adhesive had flashed off completely. Glue is off-gassing under the rubber making those wrinkles. Eventually they'll go down. Doesn't look so good but it won't leak or peel up.
Chicken run looks sloppy and unfinished. Asphalt shingles would look a lot better there. As it is,a piece of uncured flashing material could be used to make the transition a bit tighter.
IMO, epdm is a commercial product. It's hard to make it look pretty. Even done well its not the nicest stuff to look at, especially on something that from the pic looks to be fairly visable.
Jim,"Chicken Run"?Evidently, there are a whole bunch of roofing terms I have never been exposed to. I'm assuming you're referring to where the 6/12 roof intersects with the flat roof roof and the 6/12 roof extends below the flat roof for a few feet. Is this right?
Jon Blakemore RappahannockINC.com Fredericksburg, VA
Yeah, I had a feeling that was maybe a local thing (Boston). That's what the guys I learned from called them, don't know why.
Jon ,
They used more glue than needed and like others have said -- it didn't flash off fully . Those bubbles may go down with sun and heat .
There are several things I'd have done differently . That rake gable would have been step flashed and shingled prior to the membrane going on . I would have left the shingles up 2 courses exposing more rubber at the transition - still going up at least a foot above the exposure line .
I terminate at the perimeter differently - metal goes over the field rubber , then covered with 6 " neoprene .
How is that rake going to be treated ??
Walter
I terminate at the perimeter differently
That's an approved detail, actually. We sometimes use it when appearance is very important, but as someone else mentioned, EPDM is not a pretty sight.
I would have left the shingles up 2 courses exposing more rubber at the transition - still going up at least a foot above the exposure line .
Yeah - me too. It doesn't do much good to nail thru the rubber down that low. But Jon's in low snow country, IIRC.
Which brings us back to the asphalt shingle/epdm touching question: You ever see any problems resulting from lapping shingles over the top of an epdm roof?http://www.quittintime.com/ View Image
Grant ,
It's an old wives tale that shingles and rubber react poorly .
Glue won't adhere where roof cement has been , but shingles don't cause any problems .
I know that is an approved detail , but shouldn;t there be a sealant so water can't wick back under the field rubber ?
Wouldn't you have shingled that rake so the last step could be folded under the area where the rubber was being glued ?
Most rubber I do would have slate coming down onto it so I'd use a hemmed metal under the starter course so the rough edges wouldn't cut the membrane .
Walter
but shouldn;t there be a sealant so water can't wick back under the field rubber ?
Yeah - it needs seam caulk, but that roof isn't finished yet. I'm giving them the benefit of the doubt that they just haven't done it yet.
Wouldn't you have shingled that rake so the last step could be folded under the area where the rubber was being glued ?
I'll have to go back and look - it's certainly not finished yet. I thought the rubber looked like it wasn't adhered at the steeper slope yet, so an over and under could be done on it.http://www.quittintime.com/ View Image
It's definately not finished , but I'd have caulked the field lap and the perimeter before leaving for the day .
I hope there isn't much snow there or that 6 " tall vent will be covered .
I hope Jon will take some finished pics so we can see what took place on that rake transition .
It's an old wives tale that shingles and rubber react poorly .
Not exactly - asphalt causes EPDM to turn to "jelly" through a chemical reaction.
Usually doesn't take more than a week or two to see the effect - not sure why some posters are saying they haven't seen it.
Maybe because it's untrue !
Maybe because it's untrue !
Can't be that, because it is true and I have personally seen it.
" not sure why some posters are saying they haven't seen it."Here's my opinion FWIW,the more liquid states of bitumen are still off gassing like crazy. If you've ever run a kettle, you have seen and breathed the volatile fumes.Something like plastic roof cement or ice and water shield are off gassing more slowly, but still enough to do damage over time. I've seen the Grace turn EPDM jelly like aand porous.But composition shingles have the asphalt more encapsulated and cured so there is less interaction between any volatile gasses from the shingles and the EPDM. Further, when shingles overlay EPDM, the water is runningaweay from any porosity created, so it does not become a problem.
Except that as Slateman said, he ( and I) would rather seen the lap up a foot or so instead of right down to the break.
I like to see some resin paper between the shingle and EPDM. Tyvek might do too. But I try to separate them because of "the book" not because I have ever seen the shingles cause a problem. I have seen where somebody tried to use plastic roof cement to keep wawa from back ing up and that did disolve the rubber
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But composition shingles have the asphalt more encapsulated and cured so there is less interaction between any volatile gasses from the shingles and the EPDM.
That makes a lot of sense - it's reasonable to expect the solvents and volatile gasses to be the cause of the problem.
We've certainly seen the results - the rubber turns to "jelly". However, when I have seen that, it has been a result of roofing cement, hot tar, etc. Don't think I've ever seen shingles against EPDM "in the wild", so maybe that works OK (in spite of the manufacturer's insistance the we not do it that way).
Then how come tires dont go flat sitting on a driveway?
Ok, more serious. I did once wonder ( yeah, I do that still) why for if all these millions and millions of tires are worn out , there isn't piles of rubber dust everywhere? Turns out there IS some kind of bacteria or fugus amoung us that EATS the dustified rubber.
God does have sense of humor after all. Stuff that eats rubber and microbes that clean up oil spills, and WE still need terlet paper.Spheramid Enterprises Architectural Woodworks
Repairs, Remodeling, Restorations
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If you'd let gunner show you how to nair and then get a bidet, you wouldn't be so worried about running out of TP
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That dustified rubber on roads and runways runs off, and not in a good, bouncy sort of way.http://www.tvwsolar.com
We'll have a kid
Or maybe we'll rent one
He's got to be straight
We don't want a bent one
He'll drink his baby brew
From a big brass cup
Someday he may be president
If things loosen up
I meant to reply to Walter about the snow issue, but you are correct about us not being in a high snow area. We may get 12" every so often, but that typically does not last that long.I cannot tell for sure, but I think the nails are about 7-8" up the pitch of the roof from where the flat roof meets the pitched roof. Being a 6/12, this means only 4" of vertical height, at the most. I know a lot of step flashing in this area is only 2" high, but that's also on a pitched roof, not at a transition where a slope meets a flat plane.Grant, how high would you place the first group of nails in your climate? Would you go one more course up, or would you like to see even more?
Jon Blakemore RappahannockINC.com Fredericksburg, VA
Does anyone know why this thread was moved to "Energy, Heating, & Insulation"?
Jon Blakemore RappahannockINC.com Fredericksburg, VA
how high would you place the first group of nails in your climate?
We normally leave about 6"-8" between the bottom of the 1st shingle and the pitch change which leaves the lowest nails a foot or more up the slope.
The "catwalk" is the little strip of roof beside the dormer.
EPDM adhesive is a contact cement. http://www.quittintime.com/ View Image
Walter,So, you think that too much glue was used? That's interesting, it seems on problem installations that there is typically not enough materials used.Is the glue used on EPDM like contact cement? You apply it, let it get tacky, and then adhere the pieces? If that's how it is, I could see what you mean about having some puddles that aren't ready to be mated with the opposing piece yet.As far as the rake goes, I think it will be step flashed. I would certainly expect that on a residential installation.
Jon Blakemore RappahannockINC.com Fredericksburg, VA
Jon,
When I said too much glue , I guess I meant uneveness in rolling it on either the rubber or substrate . That leaves places where it's thicker and doesn't flash off evenly , leading to these outgassing bubbles you see .
My point of snow depth had more to do with the stubby vent , although I'd have held the shingles up too courses on general principles .
Your job or just one you're monotoring ??
It's a client that we have done a decent amount of work for in the past.I noticed it when I was up on the roof and wondered if everything was kosher. At the very least, I will know what the best practices are the next time we have a flat roof installation.Actually, that brings up another question. I've seen some preach about Seal-O-Flex and the like- what do roofers like yourself, Grant, and Paul think about those kinds of materials/methods.It sure seems that EPDM is a lot more prevalent on commercial projects, but I guess that doesn't mean that the coating types are a bad thing for residential.
Jon Blakemore RappahannockINC.com Fredericksburg, VA
When EPDM was first marketed in this country and i took my classes in it, you could not get it for residential work. That market has openned up now for various reasons. It never was pretty, but then I can't think that I have ever seen a good looking flat roof of any kind. Some are just uglier than others.EPDM is a great choice of material otherwise.As for brush and spray applied roof materials, I have never seen one I trusted. That does not mean there are not some good ones, just that I have never seen them.
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Jon,
I don't have any experience with Seal O Flex , so I'm not able to weigh in on that product .
Walter
I guess that doesn't mean that the coating types are a bad thing for residential.
I've used some of the coating type roofs in the past with limited success. They are only as good as the substrate you're coating and the flashing details leave something to be desired. Like any other product, they're not the only answer to the question, but they'll work in some situations.
I see them as more of a way to extend the life of an existing roof until funds can be raised to replace it. http://www.quittintime.com/ View Image
The bubbling is where they ould have waited another five minutes for the contact cement to kick before rolling it in place.
On the transition, I'd have wanted shingles on first before the EPDM, but can still happen from under
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A brief update. The EPDM does seem to have "relaxed" a good bit. Not all of the wrinkles are out, but it's much better than before. It was hard to capture the wrinkles with the sun, but this pic will give an idea of what it looks like now.View Image
I also am pleased with the step flashing at the fascia. I think it will be fine for the life of the roof.View Image
Jon Blakemore
RappahannockINC.com Fredericksburg, VA
Jon ,
The wrinkles there now will likely remain for the life of the roof . Not a big problem though .
The " witches hat " on the vent stack still looks suspect to me though .
The rake flashing looks fine .
Walter