I’d like to use EDPM for a low slope roof. I have found a source for the material but I am having trouble finding good information on how to properly install the roofing. My supplier is good on price and quality, but caters to professionals so installation info has been hard to obtain.
My roof is small 17×12 and I will strip it down to the ply deck to provide a clean bonding surface.
I will be using .60 EDPM and due to the small size of the roof I will not have to make any joins in the material. I like the fact that if the project takes longer than I expect or I run into unexpected problems I can use the membrane as a temporary roof by weighting it down and not having to run out and buy a tarp.
I have been told to use the “ white glue†to bond the material to the roofing deck and yellow glue elsewhere. I am unsure how properly do the drip edges, flashings etc.
Of the four corners of the roof two have drip edges, one end meets a gable end of another roof, and the other side slopes steeply for a couple of feet down to the gutter. The steeply sloping part appears to be metal. There is one plumbing stack.
One other question. Is this the best material to use as I would someday like to put a deck on the roof?
Cheers,
Trev
Replies
Especially since you may someday deck it over, it is the best choice.
I'm having a hard time believing that the supplier can't provide any installation info. Probably old school by now but When I first got started with this stuff, you could only buy it after going to a three day schoool to learn all about it. The manufacturers didn't even want to sell it for residential back then.
I think some of the outlets now are Carlisle and Mulehide and that they have some info online if you Google for it. Much of what is made is from Firestone so maybe you could Google for Firestone + EPDM + installation for a PDF
I'll take a look for some photos of one we just did a deck over.
Not sure if I have details of edging showing.
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Edited 6/24/2004 10:54 pm ET by piffin
I see for your railing posts you fastened them through the decking to blocking that was up off the membrane.
Take a look at this archy's section, attached. You will see him showing 8" diameter wood railing posts with square-tenon bottom ends, penetrating the roofing membrane to socket into framed pockets below, and bear on the log beam.
For the intermediate 8" rail posts, I think I will just do your detail, and provide blocking for an un-tenoned square-cut-bottom post to toescrew into. But I have 12" diameter log posts that are supporting roof above, coming down, and need to bear through to beams over posts below, kind of like as shown for the 8" railing posts.
Will we be slitting and cutting the EPDM for the socket holes, and then doing detail EPDM and caulk application, lapping up the tenon, much as is done for any roof penetration without a boot?
Penetrating the roof that way with posts is best for structural horizontal stresses but not penetrating at all is best for the waterproofing scenario. A good roofer can help you work out the details.
Most of my decks like thios have a lot of right angles so the sections rebrace or crosss brace each other. if they are all in a straight line, it gets harder to stabilize against that horizontal.
I have done with columns supporting to above with nothing more than railings to stabilize against that lineal movement when in angles to each other. You have concerns about t6he vertical loading though. You can still deal with that by using solid blocking shimmed tight down to the deck with other blocking below the sheathing that underlies the membrane to maintain load path top foundation. you can even uise some lap cement for EPDM or contact cement to minimize movement but just be sure to allow for a drainage plane and for slip/wear sheet at any loading points.
I linked you to this thread in your other one too before finding you here.
In the attachments, I have a schematic 3D for you. in the other, Kaz exterior, there are several porches and deecks over EPDM with various post and column attachments
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I have been wondering how I should build the deck.
The deck area is 12 X 16. I haven't measured it but I would think that there is a 10-12 inch slope (in total) running down the short 12-foot side. For decking I was thinking of 5/4 PT.
I am still up in the air on how I should do the sleepers and attach the posts for railings. I had the idea I should put reinforcement under the post area and use those metal brackets that hold 4x4's and screw to the deck. They are a bit ugly but would make for a simple install.
For the sleepers I was thinking of cutting wedge shaped pieces from 2x10 (or twelve depending on the slope) and attaching a 2x4’s on the bottom to rest against the roof.
Any better ideas?
Oh and many thanks Piffin for those photo's - very helpful.
one of those photos shows pretty clearly the base board type surrond I made on the posts. it covers the butt ugly simpson hardware.
Another thing I have done that I hesitate to mention because it may not pass inspection in plenty of places, is to drill a double ended lag into the deck and seat the posts to that along with the addition of epxoy in the connection.
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But as I said, Pif, I have no real issue with the 8" dia posts that are part of the rail system. It is the 12" dia columns that are picking up the roof overhang, that come down and bear on the deck (or really, THROUGH, the deck) where I think I need to do penetrations.
You wouldn't put crush blocks under your deck, and then simply stand the column bases on the EPDM, would you? I would think not. The log column would soak up water, and the point load on the EPDM would not be good for the membrane's health and longevity, also.
Here is a pic that shows a tenoned column with the tenon penetrating the EPDM-skinned deck, the tenon going through to bear on structure below. I don't show the deck joists, nor sleepers or deck, but the tenon shown is about correct scale. It only allows for a "boot" height of perhaps 2".
I would never do it that way without at least a four inch tall flashing detail but it would certainly work. That is why I mentioned that you should work out the details with your local roofer. I could do five or six ways to detail that before hitting one that he is comfortable with. It will also be connected to how the log/timber people are used to doing things and if they have the tooling to do what you want. Cutting that deep of a sockete or mortise into the bottom of the stand post log is not something I would relish. going into the long grain.
In the picture Kaz ext, I did just use blocks to support those round columns without penetrating the EPDM. There is another ply of rubber for wear, then a 1-1/2" PT, then the fir decking. The columns are hollow and come from Hartman and Sanders with a special base that holds them up off the deck so they do not soak up water. Then the Doric Torus base trim is a fibreglass unit that slips down over to hide it all. The special base is fastened with screws short enough to not penetrate the membrane.
In your case, I think that what I would do is to have base plates welded up with a flat weight spreading base plate and a vertical round rod about 3/4"threaded rod/wallbolt. The base would be about 12" x 12" with screw holes at the corners. It would seat on the EPDM and be screwed down through it. Then a double ply of the rubber flashing could seal the screws of over the base up to the rod.
Now you can frame around it, support block up from it, deck over all and seat the log post on the deck ( or space it up slightly with PT or composite shims) by just drilling a 7'8" hole in the center of the column
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So, as I read your post, you suggest transferring the column load down through a 3/4" diameter threaded rod?
most of the load would be on the deck surface. The purpose of the rod would be to keep the post from sliding around, but you could also notch things up by going to a one inch threaded rod, and placing a nut and heavy fender washer for support to elevate the post of the deck and let the metal base of the unit totally support the load. That eliminates your concern about placing the load directly on the EPDM and compressing it.
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While I was posting, so were you. Here is what I think you mean. But, I am not quite as comfy with this as with the bigger plate on top.
The tree column, sitting on the decking, is trying to crunch the decking onto the hex nut. It'll crunch. With a 15 foot column spacing, an 11 foot porch roof width, and a design snow load of 50 psf, the live load alone is putting over 4100 pounds of load down through that column.
Your GIFs above shows about what I meant except for the large heavy fender washer but you are right. Your pipe loading method distributes the loading better. Over a 12x12 plate that comes to only about 29PSI
but with either of these, you would not need the extra 16x16 waer pad underneathe. You can screw them dowm to the EPDM and then use the rubber (uncured neoprene) to flash over them the same you will be doing on the edge metal flashing to seal against leaks.
Next problem - how to be sure it doesn't rust out. No welder likes to work over galvanized. Maybe you can find someone there who works in Aluminum. failing that, you want them painted pretty good.
PS, If you patent these, I want a six pack for a consult fee, or you could market them as "Piffin Post Pods" Pal.
;)
Will you be at Rhodefest?
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I was thinking about the rustout, too. If we do this, we'll see what a sandblast and epoxy paint job costs. Maybe we'll go crazy and ask for an option price if stainless.
Patent's applied for, with you as inventor, and me just the drafting guy. BTW, I once had a job doing inked patent drawings, and did one for a dog urinal.
We'll likely be at Rhodefest, but we had better firm up some room reservations, huh? Calendar-wise, it is seeming like it's right around the corner.
yeah! your rooms might end up being out a ways. Mine was the last room available at the Hamilton Village and I got that reservation a month ago. And Mike got the last Trolley car available for a town tour. Sign your self in with him for that too.
That Jazz festival brings in lots of folks.
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As we speak, I am trying to put the squeeze for bunk space on my cousin, who keeps his 44-foot Mason at a marina in Newport. The twinkling lights of Mike's happy little island are right across the harbor.
OK, here is a little sketch to provide food for thought. Suppose the 12" dia tree column that needs to bear down through this deck to structure below, has a square-cut butt end with a 1" dia x 6" deep hole bored in its center.
We frame up the deck atop the lower structure, using maybe 2x12 PT joists, taper ripped to provide the top slope, put some solid crunch blocks where the columns will bear, then sheath with 5/8 CDX, roof it with EPDM, place 16x16 EPDM "wear pads" where the point loads go, then top it off with the steel thingies I show here.
The big bottom plate is 12x12, and welded to it is a 3-1/2" length of 3" pipe, cut to match the roof bevel on its bottom end, then a 4x4 plate is tacked on, with a 3/4" x 5" stud welded on the top center. The pipe is bearing the column load.
It is detailed out so that the top plate will sit just proud of the finished deck surface. We deck around it, and sit the column on it. Presto! No funky tenons to cut on the logs, no penetration of the EPDM roof.
Screw the big plate through the EPDM and do an EPDM flashover? We can countersink-bore the holes and use flathead screws. Or just let it sit, and don't screw? Just sitting it and not fixing its position might cause us to kick it out of position, but hey, we're careful.
Another possibility you could look into for post attachment is the bases from Weatherbest railings which are a heavy galvanized bolt down that holds the wood post and could be bolted to in a number of ways. The flange on the roof surface could them be flashed over.
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OK, Here we go with a few - from two different jobs.
dsc07 shows a finished edge.
First, you would have installed the sheet by laying it out. You would want help because it is heavy stuff. Lay in place approximately and then you carefully fold back half of it without moving it around. You apply the contact cement to the roof surface and the EPDM and then take a break while it drys for 20 minites to an hour, depending on the labnel and the temperature.
Then you work it slowly back across into place, broom it to good contact and then fold the othe hlaf back and repeat the process.
In the picture, the main sheet over lies the shingles at the break by about 2"
Then the leaded caopper flashing was nailed down over it.
Then uncured neoprene flashing was applied using another cement and lap cement from caulking tube applied to the edge of it.
You can see that he used 6" neop[rene for this and really should have had 8" wide because of the width of the flashing on the surface.Those chaulk lines are my ref for the sleepers to add the deck.
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dsc 6 shows the sleepers in place on that one. The sleepers here ran perpendicular to the line of water flow fro the pitch of the roof and I wanted to get the deck surface leveled so I ripped each one a different height. The pads are there to let water flow under the sleepers and to keep friction from wearing away at the roof suyrface itself. Another way to allow water flow would be to dado out for it.
I keep the pads in place with a dab of the EPDM lap cement because I know it is not going to eat through the rubber roof chenically.
in other situations, I rip the sleepers in wedges to make the roof lefvel up or just lay them equal and let the deck surfae Pitch slightly with the roof plane like in photo dsc 45. You see that I have to use temp furring to keep things in place until i get to start applying the decking.
47 shows a couple of details. I have to add the blocking for post attachemnts before starting to lay the Ipe'. There is also another flashing added to the sleepers for appearance from the ground level later and to keep the largest of the creatures from deciding to take up habitation while still leting water flow from under. Picture # shows the edge from finished.
#65 - be sure to use screws short enough that you don't puncture the rubber roof. These are stainless steel trim heads with a #10 Torx bit from GRK.
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77 and 78 show that once you are finished, it won't look too bad.
Now I know some of these guys are worried that I am up there with no safety gear, etc.
#44 is for them.
see the safety rope and harness?
And the blockade over the door so the owners don't go sleepwalking?
And the post base blocks?
I ran the first three or four pieces of decking along the edge, then installed myu temp railingsright atthe outsdie, then finished the deck and the railings. Once the permanent railings were on, then i reached over them wearing the harness of course, and dismantled the temp railings.
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Edited 6/24/2004 6:19 pm ET by piffin
Piffin, that's a beautiful deck.
I wanted to ask you about the railing construction...I have a flat top back porch with fresh epdm roofing, very similar to your project, but I still need to build the railing. How did you build the posts? Are they 4x4 wrapped with 1x, or? What materials did you use?
Thanks!
I've used about five different methods on variousdecks, according to what is best for the situation. I'll come back to this later since it is bedtime now and a long answer. Might even be worthan article for the magazzine.
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Pic 73 seems to show three nails/screws in the end of each board...why?
Whenever you are asked if you can do a job, tell'em "Certainly, I can!" Then get busy and find out how to do it. T. Roosevelt
Because I was usding such small trim head shor tscrews and the ends are where wood movement ensions seem to bring out the worst. It was just being conservative enough to be sure I had less chance of callback
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Hi Piffin:That is a beautiful deck. May I ask how you attached your posts?
Also Ipe is a great wood, but how is it that clients choose it over mahagony which also seems to hold up well. My current possible job is a big 850 sq foot monster on a flat roof. My clients are concerned about making repairs to the roof once the deck in in place. Their neighbors have solved that issue by building the deck high enough to crawl under it. I am tempted to do the same. Right now the 4x4s are spaced 6 to 8 feet apart. If I raise them 30" you should be able to get under there to make a repair.Dan
LOL, that's an interesting concept, but it just invites more debris and vermin that are more likely to CAUSE a leak.Use the thicker 60 EPDM instead of typical 45 and work carefull so as not to cause a leak. Once installed right, it is UV rays or wear and tear from traffic that ages or wears out a roof. most leaks are caused by accidents, have of which will need more extensive repairs than you could do be crawling a space like that. I wouldn't recommend that approach.For posts, look into the way Fypon hardware works. One of those photos above linked shows a 2x12 in with the sleepers near a corner. That is to anchor the lag screws through the IPE1
I wrote an article on post mounting in decks magazine a few months ago. If you can't find it, let me know and I can email it to you if I can find it in my pc here.As for IPE` vs mahogany, the ipe is less expensive and stronger, allowing for longer spans. It is probably more rot resistant too, tho I wouldn't argue that point strongly.
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"http://www.deckmagazine.com/article/144.html"Google is my friend
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Hey Piffin
Obviously beautiful deck.
Like the details.
unrelated to the EPDM, what fasteners do you use for the IPE.
I've been installing Massaranduba more than IPE. Its a bit softer and easier to work with and the 3 clients I have sold to like the color of the Massaranduba better. (I let them choose between the two or synthetics and all 3 picked the Massa.
Regardless, what fastening system have you used and favor? I only used the EB Ties and they have worked fine but curious if any others are better.
trimhead SS GRK screws
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I'm sure Perfesser Piffin covered it all, but here's a little input. I only did one rubber roof, but it was perect for the low-slope roof I put it on. I bought all the components from a small, local roofing supplier and the were very helpful with information and even loaned me a video on how to apply the roofing. Maybe you could get more help at another supplier.
One step you did not mention was underlayment. I screwed down 1/2" fiberboard underlayment designed specifically for EPDM roofing. It provided a good surface for the glue to stick to and seemed to protect the rubber from any sharp edges on the sheathing.
The details at the edges took more time and money than the rubber roofing itself. First, the rubber was lapped over the edge. Then, the aluminum drip edge was nailed down. Then a rubber strip was cemented over the top. Finally the joints were sealed with a special caulk. I've seen it done quicker and dirtier with a screw-on strip right through the rubber, but that is not the recommended way to go.
Al Mollitor, Sharon MA
Actually, you probably covered more on the rubber installation better than I did. I spet more time on the furture decking possibility, just 'cause I had more photos that way. That video sounds like a good deal for newbies.
The underlayment was a good point too, especially since this one is a tear off of an old one so there will definitely be some uneven surfaces. I always use a good ply, Advantech, or the gypsum underlayment. The different roofers have different underproducts but they all want it clean and smooth for good reasons, one of the best is that many older sheathed roofs have plain edge ply but for single ply roofing, you need a T&G joint or double ply - breaking joints up to eliminate movement.
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That was my next question - what do I put down first. The insulation is it safe to walk on or put a deck onto? I mean would it crush down?
Do the nails that hold the drip edge on go through the rubber at all? I am thinking they must then you add the flashing stip on top.
The tape used to seal the flashings or drip edge, is it a self stick product?
I searched google and found some info on the Firestone website. Hard to understand. Wish they had a few more images to show what they mean.
Edited 6/25/2004 11:02 am ET by Trev
Yes, the insulation is safe to walk on. It is commonly called recovery board and is similar to homasote. I don't like it. I have found it can deteriorate over the years under the rubber. Foot traffic over time is really bad news as well. And yes, the weight of a deck can compress it. We like to use Advantech T&G screwed and then rubber directly to that. Do not nail the Advantech. The nails will back into the rubber and poke holes over time. If you already have a nailed plywood deck, then you should go over it with another layer. This layer need not be T&G but it must be screwed. Obviously, the screw heads must be below the surface.
Yes, you nail the edging through the rubber. And then it gets flashed with the stripping which is peel and stick. The base rubber must be thoroughly cleaned with the manufacturer's cleaner. At one time it was necessary to seal the tape edges with lap sealant. Carlisle no longer requires this.
carpenter in transition
I guess it depends on the brand. I have not yet seen a peel and stick. The uncurred Neoprene has a protective strip to remove to keep it clean but not stickum under it. Stick need the adhesive.
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Piffin,
That is a flat out gorgeous deck that really does justice to the breathtaking view. Trex would look crappy in comparison.
I have a few concerns about longevity and durability. (Huge for me because I'm so wicked cheap). I agree EPDM is really the best membrane to use.
In my location (Denver), cedar or redwood will last only 10-20 years. Yearly maintenance would be roughly $300 and add maybe 5-10 more years. But that's a hassle I don't want for me or a client.
When trees are nearby, a lot of organic mulch tends to blow in and fall through the boards and collect under the deck. This can be ugly in the best case. What do you suggest to clients to handle cleaning? In the worst case, the mulch stays wet all the time and rots the sleepers. Denver requires the deck in "removable sections" for roof maint. More hassles.
I'm not being critical, I'm just trying find the holy grail of a maintenance free, nice looking, long lasting deck.
Well, I'm floored by why they might recommend that. Removeable sections would also lend to a greater possibility of lifting off in tornados and high winds.
But a creative interpretation of that rule would demonstrate that deck boards screwed down are indeed "removeable" and would allow the insertion of a shop vac to suck out debris where it puddles.
The traditional deck surface here has been CVG Fir but that quality has gone down the past ten years to where I get 15-20% waste which makes the Ipe more competitive. .85 for fir and 1.08 for Ipe
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I didn't realize Ipe had gotten so competitive.
Edited 6/27/2004 6:31 am ET by KevinD
What brand(s) are you using?
By the way, what a deck ! And what a view ! Tough job to finish, I'm sure.
carpenter in transition
I guess what you are getting at is that Ipe` gets marketed under the copywrited trade name of Ironwoods, but I get it through my yard and sometimes from wholesaler or broker.
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actually, I was wondering whose rubber you were using ?
carpenter in transition
It doesn't much matter whose rubber you use. There are only two manufacturers of EPDM in the country. Everyone else buys their rubber and adds what counts- flashing details, knowledgable installers, and warranties.
Rather than build a wood deck on top of my EPDM roof, I installed 2'x2'x2" thick roof pavers over a slip sheet. The slip sheet is just another piece of EPDM. The pavers have 5 "dimples" molded into the bottom of them to allow water to flow underneath them. This system has worked well. I recently had a leak in the area, and could pull up the pavers quickly to check the condition of the underlying EPDM. Luckily, the leak wasn't in the roof surface, but the parapet wall coping which surrounds the roof deck.
Keep in mind that asphalt (maybe from roofing shingles) will break down EPDM over time.
Check Genflex.com or Firestone.com or JM.com for roofing details.
Bman
Edited 6/27/2004 11:17 pm ET by BMan
Oh - OK. Her'sright that all the rubber roofing in north America comes out of two or three plants and then gets branded and distributed from there. mine is johns Mansville rght now.
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How do I handle the gable wall end wall and steep sloping section that runs down to the gutter?
I would think I would need a cant strip and perhaps some flashing under the membrane at the wall.
As for the steep metal section ( two feet wide) that runs from the low slope to the gutter, I am wondering if glue by itself will hold the membrane.
For walls, you just roll the membrane on up it and do a tuck fold in corners. A wall shows in at least one of the photos I showed. we removed the siding and re-installed it.
Where it rolls over a steeper edge, the contact cement will hold it and it will still be part of the membrane above it so it won't justy tear loose and slide downhill.
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Trev,
I don't know what your time line is, but there is just the article for you coming out in issue 166, Oct/Nov.
Brian P.
Trev, here is an installation handbook you can download online >>>
http://www.roofingproductsint.com/handbook.htm
That handbook covered it all thanks. Now I fell confident I can do the job.
I assume "fell" is a typo. ;-)
But ya, that covers the basics pretty well.
Yikes. That's not a slip I want to make.
Do you know if I put a deck on top of the EPDM do I still have to glue it down? Will the weight of the deck be enough to keep it in place if I only glue the edges?
"Ballasted" installations are common, but different in some aspects. The suppliers should have the procedures.
I would worry about it bunching up, but it should be ok if you insist on doing it that way.
But what is the big deal about gluing the whole thing?