# Mod-Bit roofing in hot asphalt



## Pie in the Sky (Dec 21, 2011)

OK all you hot roofers out there, I have a very important question that I need some help on. A little background, I looked at a job with a blister in the cap sheet and I was able to peel up much of the sheet when I cut the blister. The contractor proceeded to remove several more sheets from the same area, he said he remembered it being too cold that day. 

My understanding has always been that the EVT required for built up roofing is so that the heat of the asphalt activates the asphalt in the membrane sheets, therefor Fusing the sheets together, rather than just adhering the sheets together. Am I wrong??? When A sheet was pulled up the following 3 means of failure were observed:

1. Cohesive Failure - Asphalt was evident on the underlying ply and the bottom surface of the membrane cap sheet due to a failure of the cohesive bond of the asphalt and not a failure of the bond between the membrane cap and the asphalt. In this area, it was evident that the asphalt was hot enough and properly installed to activate the asphalt within the membrane cap sheet and “fuse” the sheet to the underlying base ply.


2. Adhesive Failure – No residual asphalt was present on the bottom of the sheet. The adhesive bond was broken between the asphalt and the membrane sheet. The asphalt appeared “dull” in finish because it was not hot enough to activate the asphalt in the membrane cap sheet when it was installed. This was referred to as “beginning to adhere” and was deemed an acceptable application practice by the manufacturers representative. 

3. Non-Adhesion – No residual asphalt was present on the bottom of the sheet. The underlying asphalt appeared “shiny” in finish and the cap sheet still had the talcum powder on the bottom of the sheet. This indicates the underside of the sheet never came in contact with the asphalt. This was deemed unacceptable by the manufacturers representative. The contractor was instructed to cut a slit in the blister and adhere or torch the inside of the blister until it is adhered and then install a membrane patch over the slit.

Would anyone find it acceptable to just adhere the sheet? I know the base plies were installed in hot enough asphalt because you could see the bleed through on the sheet.

Thoughts???

*Dustin T.** Smoot, RRC, RRO, LEED AP**| Forensic Specialist | Pie Forensic Consultants* | Corporate Headquarters: 6275 Joyce Drive, Suite 200 | Arvada, CO 80403-7541 | Nationwide: 1.866.552.5246 | Local: 303.552.0177 | www.pieforensic.com | http://blog.pieforensic.com/


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## Miami Roofer (Jul 7, 2011)

Without getting in to a debate over terminology, I've always used the term fused when referring to hot air welding a PVC lap etc. & adhered when mopping. That being said, the ply sheets in the BUR should bond together and not separate. As I understand, a holiday was found, cut open & you were able to separate the cap from the inter-plies (like peeling an onion). In other words, there was no bonding of the plies. Sounds to me like the presence of moisture when mopping or the asphalt was to cold in that area. Possibly the the guy mopping was getting ahead of himself & trying to mop too far- you know those guys who go 12 feet in one stroke. What was the ambient temperature that day? Was he phasing the roof and the plies in place too cold ? Or was his cap sheet left out in 20 degree weather? I'd get with the contractor and find out all those conditions.

But to answer your question, you should not be able to separate the plies from each other by hand if the roof was installed correctly and there is no material failure.

I'm curious,what was the system used? 

http://www.affordableroofingcontractors.com


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## Pie in the Sky (Dec 21, 2011)

All of the above. Its a Big job in a CO winter and your typical GC wanting the project done and contractor wanting to be semi profitable. I cant speak too much about the project or post photos but I wish you could see it. Thanks for the input...

*Dustin T. Smoot, RRC, RRO, LEED AP| Forensic Specialist | Pie Forensic Consultants* | Corporate Headquarters: 6275 Joyce Drive, Suite 200 | Arvada, CO 80403-7541 | Nationwide: 1.866.552.5246 | Local: 303.552.0177 | www.pieforensic.com | http://blog.pieforensic.com/


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## shazapple (Dec 3, 2010)

EVT should be measured at the mop instead of the kettle. Chances are it was barely within range at the kettle, and by the time it was put down on the roof during winter it was too low. 

If you are not worried about the remaining mopped asphalt delaminating (or if you can remove it) I would mop down a new cap sheet.

Edit: is this SBS or APP?


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## Pie in the Sky (Dec 21, 2011)

I use +or- 25 degrees from EVT for installation for this type 4 it is 425 to 475. When I was there the best i saw at application was 400. Unfortunately I cannot make them stop only tell them that it is not following manufactures requirements. I really just wanted clarification that the sheets should be "fused" and not just stuck together. 

SBS I have never seen APP applied in hot asphalt. I think it needs the higher temps of a Torch...

*Dustin T. Smoot, RRC, RRO, LEED AP| Forensic Specialist | Pie Forensic Consultants* | Corporate Headquarters: 6275 Joyce Drive, Suite 200 | Arvada, CO 80403-7541 | Nationwide: 1.866.552.5246 | Local: 303.552.0177 | www.pieforensic.com | http://blog.pieforensic.com/


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## 1985gt (Dec 21, 2010)

Blisters are generally caused by moisture. If you can peel the cap sheet off it was too cold. You may even be able to see some hints of mop marks in the asphalt. If the kettle was 400 deg it was close to 350-375 on the roof depending on building height (how far was it pumped) , if it was pumped in to a lugger, How long the lugger or bucket of hot set on the roof and or how slow they were going. The moper also could have been too far a head. 12' isnt to far a head if the setter is doing his job. Also if the hot was being pumped up to the roof was the pipe insulated? If not this will cool down the hot very quickly. If you were up on the roof while it was being installed did the moper look like he was going to chit him self? If so it was too cold :laughing:

If the manufacture says that is an acceptable way to repair it then so be it. They are the one's footing the warranty right?


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## Pie in the Sky (Dec 21, 2011)

1985gt said:


> If the manufacture says that is an acceptable way to repair it then so be it. They are the one's footing the warranty right?


I never go by this way of thinking. Occasionally I am hired to make sure a roof is installed correctly. Roofing warranties are garbage. This one only last 10 years. We’re installing a 30 year plus roof. Good roofing practices and the NRCA manual (written by contractors) is the only way to inspect. 

Roofing warranties are nothing more than another moneymaking marketing plan. They wouldn’t offer them unless they were making out in the end. Plus what do they cover. I’ve seen a warranty claim where an improperly installed seam opened up letting water into a server room. There was over a hundred grand in damage. The Manufacturer paid the roofer to install a 25$ patch. Meanwhile the owner is trying to figure out how to pay for new servers. I will take a properly installed BUR by a contractor I trust any day over a 30 year warranty. Just read one of the warranties. They are garbage, they are there to protect the manufacturer not the owner. 

I will write a post on warranties one of these days so everyone can put in there two cents…


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## Pie in the Sky (Dec 21, 2011)

GT- Guys like you act like all contractors are good.  Theres some real talent among people on this forum and you are one of them, but were talking about a small percentage of roofers. MOST DONT CARE.. you have to have fought that. The good roofers bids were always higher and that just means the owner would pay me more to fight the "Roof Hack"


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## 1985gt (Dec 21, 2010)

Pie in the Sky said:


> I never go by this way of thinking. Occasionally I am hired to make sure a roof is installed correctly. Roofing warranties are garbage. This one only last 10 years. We’re installing a 30 year plus roof. Good roofing practices and the NRCA manual (written by contractors) is the only way to inspect.
> 
> Roofing warranties are nothing more than another moneymaking marketing plan. They wouldn’t offer them unless they were making out in the end. Plus what do they cover. I’ve seen a warranty claim where an improperly installed seam opened up letting water into a server room. There was over a hundred grand in damage. The Manufacturer paid the roofer to install a 25$ patch. Meanwhile the owner is trying to figure out how to pay for new servers. I will take a properly installed BUR by a contractor I trust any day over a 30 year warranty. Just read one of the warranties. They are garbage, they are there to protect the manufacturer not the owner.
> 
> I will write a post on warranties one of these days so everyone can put in there two cents…



Your other option is to tear off the whole roof and redo it. IF your fighting the roofing contractor you will lose this one since the manufacture has already said this is how to fix it and get a full warranty what ever it is.

I don't know of a good way to tear off just the cap sheet. At some point in the roof the felts will come with it. After that the insulation will too. SO then your down to the deck. 

The roofing contractor will only do what the manufacture suggest. So then you would be looking at court. I don't see a way anyone but the contractor and manufacture will win.

If you wanted a 30 year roof they should have hired a 30 year contractor, If he can't hot a cap sheet down correctly there will be other problems in the future. 

As far as the warranties go I would some what agree. In the case you provided that is where the contractors insurance covers the interior damage. Yes I've read warranties before I've been up against manufactures before, this is why we stick very few manufactures one's that hold up on their end of a deal. 

If you have ever seen Tommy Boy the saying on guaranties applies here. "I could get a good luck at a T-bone by sticking my head up a bulls ass but I would rather take the butchers word for it" Warranties are generally not worth the paper they are written on unless they are backed up.


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## Pie in the Sky (Dec 21, 2011)

It seems like we had a good contractor, I’m covering my butt at this point, I recommended A few test cuts randomly selected, then we peel them with all parties present and see what kind of adhesion we get. Ultimately, the owner can choose not to accept the roof at my recommendation. The case would settle with the contractor and manufacturer splitting the bill. I don’t want this, This isn’t in anyone’s best interest. I’m not one of those guys who finds faults just so I can write something up. But this is improper installation. All I can do is give my recommendation cause my name is on it too. Beyond that, they can deal with it. 

It all comes down to the membrane and asphalt being too cold at application.


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## Miami Roofer (Jul 7, 2011)

Well Pie, you have the correct terminology when saying fusing according to NRCA. In fact, that is what they expect from SBS membranes. 

1985- A cold weather application memorandum was sent to me last week that specifically warned against "long mopping" and stressed that the stroke should be 5'-6'. Yes, I know they'd kill a guy on a big roof and I also know that one has to be practical when roofing. Guess what I was getting at is the issues pie brought up was potentially caused by those factors. I think we are in agreement as you listed the additional scenario.


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## Pie in the Sky (Dec 21, 2011)

1985gt said:


> If you have ever seen Tommy Boy the saying on guaranties applies here. "I could get a good luck at a T-bone by sticking my head up a bulls ass but I would rather take the butchers word for it" Warranties are generally not worth the paper they are written on unless they are backed up.


"If you want me to take a crap in a box and guarentee it I will, Ive got alot of free time..." :laughing:


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## 1985gt (Dec 21, 2010)

@ Miami, I would agree on the cold weather part, 5'-6' would kill you on a big roof but going back and redoing it would kill you more. This is a case where experience is the big factor. So many variables get involved in this case. 

@ Pie, Good luck with it. I would think taking various test cuts would be the logical thing to do. Good luck either way.


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## Pie in the Sky (Dec 21, 2011)

You want to talk about killing time??? They are now Mopping 4' of the sheet, then 4' of the roof deck. Tons of asphalt, tons of extra labor.


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## Hutch (Dec 5, 2011)

Pie in the Sky said:


> You want to talk about killing time??? They are now Mopping 4' of the sheet, then 4' of the roof deck. Tons of asphalt, tons of extra labor.


That's ridiculous... Whoever dished out the specs for that process should be forced to swing the mop for the entire job. Not to mention how crappy it would look as a finished product. Asphalt would be all over the roof. 

In the situation you described, the contractor should (without any argument whatsoever) cut out the blisters, and mop down additional plies and cap over the areas that failed to adhere properly. Hopefully, he'd learn from his mistakes and wait until the weather is above 40 degrees and heat his asphalt to an appropriate temperature. Was there no workmanship warranty provided by the contractor?


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## Pie in the Sky (Dec 21, 2011)

THere is a contractors warranty but only the standard 2 years required by all manufacturers.. I could seriously write a Book about the different factors in this job. Due to the project, I really cannot get too deep into it.


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## 1985gt (Dec 21, 2010)

Pie in the Sky said:


> You want to talk about killing time??? They are now Mopping 4' of the sheet, then 4' of the roof deck. Tons of asphalt, tons of extra labor.


? That's what they are doing to patch it? Back moping and flopping the sheet?


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## Pie in the Sky (Dec 21, 2011)

No the roof was not complete, this is there new installation technique to get the asphalt in the sheet to activate. The Manufacturer is ok with it and it seems to be working. Havent been down there in a while. My only comment was "if this is a fix, isnt that basically admitting the rest of it is done wrong?" whatever, all I can do is give my Professional Opinion from my expeience... oh and reference materials written by your peers.


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## 1985gt (Dec 21, 2010)

Working on the field of the roof there should be no need at all to mop the sheet first and then the roof. If they can't get the asphalt hot and the right amount down while moping they shouldn't be doing it. 

What you described is back moping, like hanging flashings.


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