# Help with a small commercial roof (EPDM)



## Anthony2014

<P>My company does windows, siding, and shingled roofs, not flat roofs.</P>
<P> </P>
<P>I bought a building in 1998 with an EPDM roof installed around 1994 over an office that is 900 s/f.  This winter a seam split from the ice and in poured the water.  I shoveled it the rest of the season.  It ponds in the center, and so there was quite a bit of water.  I had a friend look at it who said I could just do repairs going forward because the rubber is in decent shape, but as I intend to hold the building long term and don't want to sweat the winter, I'm going to bite the bullet.  In the meantime I had these patched, but fear more problems.</P>
<P> </P>
<P>My questions are:</P>
<P> </P>
<P>1.   Are flat roofs always truly "flat" or can they be installed with a pitch without using a tapered system?   As it is it ponds in the middle and if a seam splits, that's a lot of water.  If it had been pitched I wouldn't have had so much trouble as the water would've run off.  I've priced materials for a tapered and standard which is a sizable difference.  Prefer not to spend that much.</P>
<P>2.   Drainage.   The north end of the roof is  over the sidewalk.  The east and west side have a 2' wall up the sides, and the rubber is run over with clay caps or tiles over them.  The south side is a 6' wall of an apartment, and the scuttle is then in the southwest corner.  Last year when doing landscaping I connected the tubing underground to one of those popup drains.  I'm wondering if this is a bad idea as it is the only drain and seems like this could clog easier and be harder to free up?  How do people handle these?   Should I change the location of the drainage/scuttle?  Is the pop up system ok?  I'm afraid to pitch to the street-side because of fear of leaking at metal flashed edges and two perforations (curbside mounted signs) although water drained from the front would have to travel a much shorter distance.</P>
<P> </P>
<P>I've tried to post the pics to simplify without success.</P>
<P> </P>
<P>Suggestions appreciated.    Thanks   <IMG class=inlineimg border=0 alt=0 src="http://www.roofingtalk.com/images/forums/smilies/thumbsup.gif" smilieid="116"></P>


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## roofermann

Please edit your post.


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## 1985gt

1. yes you can replace the roof and install a tapered insulation system. You could also install a drain at the low point if you wish also.


2. I would not run it to a pop up drain in the ground. One drain is plenty (if the scupper is the right size) for 9 sq.


Editing your post would make it easier to read. I think you need like 5 posts before you can post pictures and that would help a lot.


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## Grumpy

roofermann said:


> Please edit your post.


 The forum software is bugged and does this automatically. Then again maybe he copied and pasted his post for another forum. Who knows, but it's happened to me any many times. Maybe one of the reasons the forums popularity died down after the last major update.

First dtermine why it is ponding. If it structural, you must fix the structure to solve the problem. If it is a minor sage or settling, and not a cracked or rotten rafter or joist, then you have other options.

Sometimes simply filling the pond area with additional insulation will fix the pond. Other times a fully tapered system is necessary. 

EPDM membrane lasts pretty much forever. It's the seams and penetrations where it fails. I have done several seam restoration projects and added years to the epdm roofs. 

A "flat" roof is really low slope. Nearly all roofs are designed to drain with some slope. Often only 1/8" per foot, sometimes less. Though during WWII some key buildings were actually designed to hold water so they would appear to bombers to be fisheries and be spared the bombing. That's a pretty rare circumstance where a roof would be designed to actually hold water. 

If the membrane is over the clay coping, that is wrong. If the membrane is beneath the clay coping that is proper.

You should not be afraid of leaking edge details. "Sandwich" the metal with membrane and it'll never leak. Field membrane wrapped over the membrane, self flashing box style gutter installed, integral gutter flashing stripped in with additional piece of membrane. Done. Then again changing the pitch of the entire roof is likely unnecessary and when ever people talk to me about changing the slop of their flat roof are usually over complicating the solution to a problem.


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## Anthony2014

roofermann said:


> Please edit your post.


My company does windows, siding, and roofs, not flat roofs.
I bought a building in 1998 with an EPDM roof installed around 1994 over an office that is 900 s/f. This winter a seam split from the ice and in poured the water. I shoveled it the rest of the season. It ponds in the center, and so there was quite a bit of water. I had a friend look at it who said I could just do repairs going forward because the is in decent shape, but as I intend to hold the building long term and don't want to sweat the winter, I'm going to bite the bullet. In the meantime I had these patched, but fear more problems. My questions are firstly, are flat roofs always truly "flat" or can they be installed with a pitch without using a tapered system? As it is it ponds in the middle and if a seam splits, that's a lot of water. If it had been pitched I wouldn't have had so much trouble as the water would've run off. I've priced materials for a tapered and standard which is a sizable difference. Prefer not to spend that much. Secondly, Drainage. The north end of the roof is  over the sidewalk.  The east and west side have a 2' wall up the sides, and the rubber is run over with clay caps or tiles over them. The south side is a 6' wall of an apartment, and the scuttle is then in the southwest corner. Last year when doing I connected the tubing underground to one of those popup drains. I'm wondering if this is a bad idea as it is the only drain and seems like this could clog easier and be harder to free up? How do people handle these? Should I change the location of the drainage/scuttle? Is the pop up system ok? I'm afraid to pitch to the street-side because of fear of leaking at metal flashed edges and two perforations (curbside mounted signs) although water drained from the front would have to travel a much shorter distance. I've tried to post the pics to simplify without success. Suggestions appreciated. Thanks. :thumbup:[/COLOR]


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## Anthony2014

1985gt said:


> 1. yes you can replace the roof and install a tapered insulation system. You could also install a drain at the low point if you wish also.
> 
> 
> 2. I would not run it to a pop up drain in the ground. One drain is plenty (if the scupper is the right size) for 9 sq.
> 
> 
> Editing your post would make it easier to read. I think you need like 5 posts before you can post pictures and that would help a lot.


What if I don't run tapered? Will a standard roof have some slope? And regarding the pop up, don't use it because it's problematic? The issue is an external drain is pretty gaudy because it runs across some significant landscaping. If I can post pics I will.


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## Anthony2014

Grumpy said:


> The forum software is bugged and does this automatically. Then again maybe he copied and pasted his post for another forum. Who knows, but it's happened to me any many times. Maybe one of the reasons the forums popularity died down after the last major update.
> 
> First dtermine why it is ponding. If it structural, you must fix the structure to solve the problem. If it is a minor sage or settling, and not a cracked or rotten rafter or joist, then you have other options.
> 
> Sometimes simply filling the pond area with additional insulation will fix the pond. Other times a fully tapered system is necessary.
> 
> EPDM membrane lasts pretty much forever. It's the seams and penetrations where it fails. I have done several seam restoration projects and added years to the epdm roofs.
> 
> A "flat" roof is really low slope. Nearly all roofs are designed to drain with some slope. Often only 1/8" per foot, sometimes less. Though during WWII some key buildings were actually designed to hold water so they would appear to bombers to be fisheries and be spared the bombing. That's a pretty rare circumstance where a roof would be designed to actually hold water.
> 
> If the membrane is over the clay coping, that is wrong. If the membrane is beneath the clay coping that is proper.
> 
> You should not be afraid of leaking edge details. "Sandwich" the metal with membrane and it'll never leak. Field membrane wrapped over the membrane, self flashing box style gutter installed, integral gutter flashing stripped in with additional piece of membrane. Done. Then again changing the pitch of the entire roof is likely unnecessary and when ever people talk to me about changing the slop of their flat roof are usually over complicating the solution to a problem.


Thanks, I appreciate your guys replies. I know time is money. This EPDM is 20 years old. The rubber looks good. I don't want to replace it spending all that money if not necessary, but significant water got in last winter, am wondering about the condition underneath. Secondly, I don't want to deal with what I did last year, and wondering how much to trust the repairs to the seams (they look good though). You have me wondering that I should just try to make sure I have solid repairs.


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## 1985gt

Anthony2014 said:


> What if I don't run tapered? Will a standard roof have some slope? And regarding the pop up, don't use it because it's problematic? The issue is an external drain is pretty gaudy because it runs across some significant landscaping. If I can post pics I will.


A lot of roofs are flat. What is the age of the building? It is possible that the EPDM roof is a layover of an existing roof asphalt and gravel perhaps. These can cause ponding issues as well. There could be other possible solutions to your issues, different tapered layouts will cost different amounts. It's also possible that you don't need tappered at all. An existing roof underneath could be the cause of the ponding issues. 

You should be able to post pictures now or up load them to imgur or something if need be. 



Anthony2014 said:


> Thanks, I appreciate your guys replies. I know time is money. This EPDM is 20 years old. The rubber looks good. I don't want to replace it spending all that money if not necessary, but significant water got in last winter, am wondering about the condition underneath. Secondly, I don't want to deal with what I did last year, and wondering how much to trust the repairs to the seams (they look good though). You have me wondering that I should just try to make sure I have solid repairs.


I'd be thinking of replacing at this point, while EPDM is a great membrane you have issues with ponding water and need to do something. Its time to think replacement and doing it right. A 20 year old roof will have glued seams as seam tape wasn't around at that time. You could cover strip the seams to get you buy with some piece of mind for a few more years to save up for a decent roof structure.


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## ToolTimeTim

At the size of the roof i would say that its worth it to go ahead and buy the iso and rubber and re do the roof. If you do it in-house you are looking under 5 grand to do the roof unless there are alot of details you left out.


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## JBL

Where's ponding if there is no to much you can used self level concrete mix and roof over And then coat it . You can Cut the section and frame it roof that section in that area and then coat it white.


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## ToolTimeTim

Or gaco the entire thing


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## Hardt Roofing

I would first find out why it's is ponding and if it isn't structural level it put with taperd iso, we would often at times use a rasp to help with leveling and if you can not put pitch to it make sure the membrane doesn't have any seams at that point.
____________
David 
www.hardtroofing.com


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## Hardt Roofing

I have used gaco before and I love it for certain situations but I think it is fairly expensive and the surface must be extra clean. You need to know that gaco is not like paint it doesn't roll very well, it's kind of like painting with bubblegum sticky itcky.
_____________
David
www.hardftroofing.com


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## 1985gt

plus throwing a coating at a problem area is always a good idea...


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## Anthony2014

*Here's the roof*

I had trouble getting the pic up before. Had to reformat them.

The top picture is looking towards the southwest corner where the scuttle is about 5 feet from the window. The area that's wet is where it holds water for extended periods. I was sweeping it into the scuttle because the seam had split and have had it repaired since. The second pic is looking northward towards the streetside. You can see where the signs are (one is down, one is up) and the parapets).

(I'm hoping for a solution where I won't have to shovel this thing when there's heavy snowfall?)


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## Anthony2014

*Help again (now that I get pics)*

So my concerns are:

1. I don't like the ponding. Obviously if I have a leak that is a lake draining into my ceilings rather than a trickle as the roof will clear all the water if it has a pitch.
2. right now there is a scuttle (one) on the southwest corner. it goes to a popup thru some landscaping. am considering switching it to the other (southeast) side (it's a hidden area), or keeping that one and adding a second there anyway (in case it clogs or fails),
3. another possibility (suggested by a crew as standard) is running the water to the FRONT with a commercial downspout (but won't that look gaudier on the front of the offices?) and also I am concerned about the idea of running the water off the front because it has to pass the only perforations (two signs). Also it seems to me the most likely leak point besides that is the terminations at the gutter line and parapets---wouldn't I be safer running it to the back as has been the case?
4. I want to tear off and add 4" iso, but do I have to have a custom "tapered" system to pitch it slightly? isn't there a cheaper way to get a pitch?
5. What of the parapets? should I cut them off flush? Seems like that would take away some of the "look", but then the rubber could be rolled over continuously and evenly instead of up the wall of the parapet and terminated there (a leak spot eventually, as now)


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## CommercialSalesWolf

DO IT RIGHT, cut a "core sample" to inspect layers and for saturation. Then determine if needs torn off which more than likely you can install poly slip sheet "Dura-Blue" and mechanically attached .40 mil Duro-last single ply membrane over top existing roof and ponding water will not be any issue at all. Duro-Last is made to protect against ponding water and Is the only flat roof system that has a 15 year warranty against ponding water.


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## Anthony2014

1985gt said:


> 1. yes you can replace the roof and install a tapered insulation system. You could also install a drain at the low point if you wish also.
> 
> 
> 2. I would not run it to a pop up drain in the ground. One drain is plenty (if the scupper is the right size) for 9 sq.
> 
> 
> Editing your post would make it easier to read. I think you need like 5 posts before you can post pictures and that would help a lot.


 I edited the post and have pics up now. TY.


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## Anthony2014

CommercialSalesWolf said:


> DO IT RIGHT, cut a "core sample" to inspect layers and for saturation. Then determine if needs torn off which more than likely you can install poly slip sheet "Dura-Blue" and mechanically attached .40 mil Duro-last single ply membrane over top existing roof and ponding water will not be any issue at all. Duro-Last is made to protect against ponding water and Is the only flat roof system that has a 15 year warranty against ponding water.


I had a sign pulled and patched where I could see there was a layer of rollerd roofing underneath which is over the 1x original decking. The thing is last year I had significant water enter the roof and believe I must have mold and damaged wood, so I'm inclined to tear off. Secondly, I think there is NO insulation and I intend to hold this building long term (and pay utilities), so going over the existing doesn't seem practical as I want to tear off an insulate. I looked up Duro-last, and would have to get a qualified contractor vs. someone I know that can install a rubber roof, likely upping my price quite a bit on labor I suspect, though I like the idea if I was going over.


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## Anthony2014

Grumpy said:


> The forum software is bugged and does this automatically. Then again maybe he copied and pasted his post for another forum. Who knows, but it's happened to me any many times. Maybe one of the reasons the forums popularity died down after the last major update.
> 
> First dtermine why it is ponding. If it structural, you must fix the structure to solve the problem. If it is a minor sage or settling, and not a cracked or rotten rafter or joist, then you have other options.
> 
> Sometimes simply filling the pond area with additional insulation will fix the pond. Other times a fully tapered system is necessary.
> 
> EPDM membrane lasts pretty much forever. It's the seams and penetrations where it fails. I have done several seam restoration projects and added years to the epdm roofs.
> 
> A "flat" roof is really low slope. Nearly all roofs are designed to drain with some slope. Often only 1/8" per foot, sometimes less. Though during WWII some key buildings were actually designed to hold water so they would appear to bombers to be fisheries and be spared the bombing. That's a pretty rare circumstance where a roof would be designed to actually hold water.
> 
> If the membrane is over the clay coping, that is wrong. If the membrane is beneath the clay coping that is proper.
> 
> You should not be afraid of leaking edge details. "Sandwich" the metal with membrane and it'll never leak. Field membrane wrapped over the membrane, self flashing box style gutter installed, integral gutter flashing stripped in with additional piece of membrane. Done. Then again changing the pitch of the entire roof is likely unnecessary and when ever people talk to me about changing the slop of their flat roof are usually over complicating the solution to a problem.


Finally got some pics up if you care to look. Yeah, the membrane was under the coping. And you have me thinking maybe I'm "over-thinking" this about changing the slope. Except that the drain now goes to a pop-up in landscaped area that would look crappy to do otherwise, so I'd rather have a scupper draining the other side. I appreciate what u are saying about edge flashing---my major leak was the seam where it ponded due to ice. My minor leaks have been from the front edges of the office where it wrapped to fascia/parapet areas. Should I cut off the parapets flush so the membrane can run over that instead of up to the middle?


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## Anthony2014

Got some help to get the pics up if you would take a look.



1985gt said:


> A lot of roofs are flat. What is the age of the building? It is possible that the EPDM roof is a layover of an existing roof asphalt and gravel perhaps. These can cause ponding issues as well. There could be other possible solutions to your issues, different tapered layouts will cost different amounts. It's also possible that you don't need tappered at all. An existing roof underneath could be the cause of the ponding issues.
> 
> You should be able to post pictures now or up load them to imgur or something if need be.
> 
> 
> 
> I'd be thinking of replacing at this point, while EPDM is a great membrane you have issues with ponding water and need to do something. Its time to think replacement and doing it right. A 20 year old roof will have glued seams as seam tape wasn't around at that time. You could cover strip the seams to get you buy with some piece of mind for a few more years to save up for a decent roof structure.


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## Anthony2014

Costwise that's what I thought too.

But my cost on materials from a material list a crew created....

firestone .060 11 square
9 square tapered iso A B C
plates, fasteners, etc = $4,000
9 square additional iso to get to R20 1000
dumpster 400
permit 200
labor (with tear off) 2000-2400 (based on 2 crews different estimates)

looks closer to $8,000. Wth. I thought it'd be 4-5kish.



ToolTimeTim said:


> At the size of the roof i would say that its worth it to go ahead and buy the iso and rubber and re do the roof. If you do it in-house you are looking under 5 grand to do the roof unless there are alot of details you left out.


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## 1985gt

That's fairly reasonable, with out actually seeing it we would be somewhere around that price.


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## CommercialSalesWolf

Anthony Do a DuroLast layover with a poly slip sheet or EPS 1/2 recover board and your golden 15 yr warranty against ponding water and covers cosequential damages up to 1 Million dollars


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## 1985gt

That's only if the durolast doesn't abandon the customer like they have in the past. 

Durolast is a terrible membrane.


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## CommercialSalesWolf

*Thats Hail Damage CMON Now LOL*

That is hail Damage not material failure. Duro-Last is by far the best PVC there is and if that roof had a Densdeck then the densdeck would have absorbed the impact and not damaged the membrane.
If you make a statement have facts not opinions
You know what they say about opinions :thumbup:
We are a Platinum preferred DuroLast installer and we do not favor or push any product we offer bids on the best fit or what the customer ask for IB Solutions is also a very good membrane that has been proven to have same flexibility on a 30 year old tearoff piece of membrane as a new piece of membrane. 1985 So if you feel Duro-Last left a bitter taste then try IB Solutions, But im here to say in my 20 years I have never seen a warranty like DuroLast and when a company has a warranty up to a MILLION Dollars there must be proof in the pudding !:bangin:


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## 1985gt

CommercialSalesWolf said:


> That is hail Damage not material failure. Duro-Last is by far the best PVC there is and if that roof had a Densdeck then the densdeck would have absorbed the impact and not damaged the membrane.
> If you make a statement have facts not opinions
> You know what they say about opinions :thumbup:
> We are a Platinum preferred DuroLast installer and we do not favor or push any product we offer bids on the best fit or what the customer ask for IB Solutions is also a very good membrane that has been proven to have same flexibility on a 30 year old tearoff piece of membrane as a new piece of membrane. 1985 So if you feel Duro-Last left a bitter taste then try IB Solutions, But im here to say in my 20 years I have never seen a warranty like DuroLast and when a company has a warranty up to a MILLION Dollars there must be proof in the pudding !:bangin:



I know exactly what it is, oddly enough this building has multiple levels, the upper levels had no damage at all. This is not an isolated case for durolast. I've seen many druolast failures exactly like this, yet no other EPDM/TPO or PVC membranes were affected. So you say hail damage, in my experiance it is not. How and why would hail hit a lower level roof and not any of the upper level roofs that are much much bigger? 90% of the durolast roofs around here are recovers over a BUR roof and the "worlds best roof" 1/4 fan fold insulation. There is many reasons why durolast roofs are bad, its really 50/50 between poor install practices and membranes that cant hold up. I don't need another PVC option although IB is a good sheet, so are many others, durolast is not.

That fancy paper with the great speal about how wonderful their warranty is, means nothing when they do not follow up on it. Again documented in many cases.


Just google the issues durolast has had. There has been many threads over it. 

Also densdeck doesn't dent like ISO and other insulations would, thus the membranes do not stretch as much, so they are less likely to be damaged. http://www.buildgp.com/densdeck-hail-resistance

Your information so far has been less then stellar there "wolf"


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## RoofTalk

Grumpy said:


> The forum software is bugged and does this automatically. Then again maybe he copied and pasted his post for another forum. Who knows, but it's happened to me any many times. Maybe one of the reasons the forums popularity died down after the last major update.
> 
> First dtermine why it is ponding. If it structural, you must fix the structure to solve the problem. If it is a minor sage or settling, and not a cracked or rotten rafter or joist, then you have other options.
> 
> Sometimes simply filling the pond area with additional insulation will fix the pond. Other times a fully tapered system is necessary.
> 
> EPDM membrane lasts pretty much forever. It's the seams and penetrations where it fails. I have done several seam restoration projects and added years to the epdm roofs.
> 
> A "flat" roof is really low slope. Nearly all roofs are designed to drain with some slope. Often only 1/8" per foot, sometimes less. Though during WWII some key buildings were actually designed to hold water so they would appear to bombers to be fisheries and be spared the bombing. That's a pretty rare circumstance where a roof would be designed to actually hold water.
> 
> If the membrane is over the clay coping, that is wrong. If the membrane is beneath the clay coping that is proper.
> 
> You should not be afraid of leaking edge details. "Sandwich" the metal with membrane and it'll never leak. Field membrane wrapped over the membrane, self flashing box style patio covers gutter installed, integral gutter flashing stripped in with additional piece of membrane. Done. Then again changing the pitch of the entire roof is likely unnecessary and when ever people talk to me about changing the slop of their flat roof are usually over complicating the solution to a problem.


I doubt that he copied it, but it's possible.


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