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Discussion Starter #1
Hello Everyone,

Can anyone compare the pros and cons of these 3 systems?

We are seeing more and more small flat or low slope roofs, and the architect's don't seem to have any rhyme or reason to spec'ing the roofing material other than "personal preference".

I've done a search, but I can't find a side by side comparison anywhere.

Thank you in advance for any help, or directions to another resource.

Best regards,

Tom
 

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Isnt mod bitumen torch down roofing? It all comes down to warranty and the type of structure. An expensive structure will have a longer life roof system. Like EPDM, PVC, or even standing seam. Its been a while for me doing it but If I remember correctly you need to be certified for EPDM. Nothing special for torch. Me personally I would never put a torch on a combustible roof again too many accidents. The warranty is only like 10 years anyway and you need annual service with penetrations and aluminum type coatings. Some company prefer the cheap up front cost and then annual contracts for business.
 

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Try a building supply yard. I know ALLIED is national and have a branch in your area. I deal with them from time to time, they have a Commercial roofing dept any salesman will be more than glad to give you costs and info on the products. Good Luck
 

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Isnt mod bitumen torch down roofing? It all comes down to warranty and the type of structure. An expensive structure will have a longer life roof system. Like EPDM, PVC, or even standing seam. Its been a while for me doing it but If I remember correctly you need to be certified for EPDM. Nothing special for torch. Me personally I would never put a torch on a combustible roof again too many accidents. The warranty is only like 10 years anyway and you need annual service with penetrations and aluminum type coatings. Some company prefer the cheap up front cost and then annual contracts for business.

The cost of the structure usually has nothing to do with a better roofing spec. In fact, the roof is the single most neglected spec, since it cannot be seen and a cheap roof will be watertight just like an expensive one, for a little while anyways.

You do not need any special certs to install EPDM. You do for warranty purposes, but that is the same for torch systems.

modified can be torch applied system, hot mair welded, some can be mopped, some can be adhered in cold process adhesives, some can be a hybrid of both.

I install modified to combustible decks often, and have not started a fire yet, but we know how to roof.

I can install modified bitumen systems with 20 year NDL warranties that do not need to be coated.
 

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Isnt mod bitumen torch down roofing? It all comes down to warranty and the type of structure. An expensive structure will have a longer life roof system. Like EPDM, PVC, or even standing seam. Its been a while for me doing it but If I remember correctly you need to be certified for EPDM. Nothing special for torch. Me personally I would never put a torch on a combustible roof again too many accidents. The warranty is only like 10 years anyway and you need annual service with penetrations and aluminum type coatings. Some company prefer the cheap up front cost and then annual contracts for business.
Wow alot to talk about here,

I can put a 20 year roof on a broken down outhouse. It won't rain on your head but the seat may fall in. The cost of the structure is not even part of the equation. Unless you're building a new office building in these parts...

Big expensive building and really cheap ballasted EPDM roof.

You don't have to be certified to install EPDM.

You also don't have to be certified to install torched Mod Bit. Unless of course you want insurance. Then you have to be CERTA certified.

Warranty? Hmm... just issued a 20 year Manufactures SYSTEM NDL for a torched mod bit job.

Some company prefer the cheap up front cost and then annual contracts for business.
SOME companies not the one I'm with, We're NOT the cheapest date in town. If you don't maintain your roof (any kind of roof) at least annually then that capitol investment goes to junk in 10 years and then you can blame the lousy roofer for selling you a 25 year roof that lasted 10 years.


We do not rely on our maintenance contracts to make our money, It's how we keep our customers happy AND dry.


As for the question

when I get back to the office in the AM I have a chart there somewhere that I'll try and post that compares, Single plies, Mod Bit and BUR against each other.
 

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Discussion Starter #6
Talos and Aaron,

Thank you for your posts. I agree with you both that the roof very often gets little attention in the overall picture. Frankly, that's why I posted. We don't do roofs, we subcontract them. I believe as a GC I have a responsibility to both our subs and customers to be as technically knowledgable as possible. I appreciate any information you can provide, or any resources you can direct me to.

Talos: that chart sounds like it will be a big help. Thank you.

Sincerely,

Tom
 

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Hey I said wasnt up on things for a while. Maybe I was thinking of Carlise either way I dont recall any modified of any kind cost as much as a PVC. I worked for a commercial out-fit years ago that promoted maintience packages since people do neglect the roof. I worked on hospitials, colleges, airports--never torch. Some of the cold process like AWPLAN or Liberty or Firestone whatever I remember were residential and small commercial. Different money, exceptions to every rule of course. Obviously the guys in the field "commerical roofers" will know better than me that why I said call your local supplier. There is constantly new material systems. Get a chart faxed to you in one phone call or even online specs.
 

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EPDM is considered a much better roof than Modified Bitumen by a long shot . Of course roofers from other parts of the country who only know torch down will disagree and that is OK to have a difference of opinion. but there are single ply systems performing well that were put down in the seventies the modifieds go bad in ten to fifteen years.

RooferJim
 

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shouldn't a roofing system be selected as what works best?I know no one single system will do every job.
so wouldn't it instead be what's the best for my application and not what's better?maybe I've been wrong all these years and one is the best.
 

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If a contractor were to use a piece of epdm large enough to encapsulate the entire roof structure, without having any seams, then that would probably be the best.

That is the cincept of the factory made custom fitted PVC style membranes.

Each roof has its own special considerations and the methods of detailing all of the flashings will mean much more than the brand or type of roofing material/product is chosen.

Ed
 

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If a contractor were to use a piece of epdm large enough to encapsulate the entire roof structure, without having any seams, then that would probably be the best.

Ed
Ed, that is EXACTLY why I am doing the seamless polyurea membranes.
 

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Also, I do EPDM and like it. I just don't see it as any better than modified.
 

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The popularity of EPDM is the fact that it's labor-friendly, and can be taught/learned extremely quick. And the ballasted system is CHEAP to put on. It also takes very few tools, and virtually no equipment to install.

"Torch-down" and "Mod. bitumen" are one and the same;
To clarify, utilizing laymans terms;

There are two primary Modified bitumen materials;

APP, (which we'll call a "plastic" modifyer), which is typically torch-applied.

And

SBS, (which we'll call a "rubber" modifyer), which is typically hot-mop applied.

There are cold adhesives for both, also.

The APP, (torch down), is another "hybrid" so-to-speak, that allows for minnimal equipment to install, yet retains the "tried & true" historical performance of asphalt based roofing. Although, it's more susceptable to "thermal-shock" than the SBS. It does require a bit more attention/skill, (if you will), than the single plys. (I know I'll get flack for that statemet!)

The SBS, (typically hot-mopped), is probably going to be the most expensive, as it requires the most equipment as well as craftsmanship to install properly. It's smelly, dirty, hot, and requires the most skillfull mechanics. It's the best system in my opinion. But finding true qualified roofers these days is a big problem.

The majority of new construction commercial for GC's we do, is EPDM

The majority of buildings we do for bldg. owners, are SBS.

What's that tell ya?
 

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Aaron,

I have seen you and Grumpy discuss this "polyurea" and other products of the same genre. I have to admit, I have absolutely zero knowledge about that product. Could you please explain what it is to me. I have presumed that it is a liquid applied coating with possibly a reinforcement mat for reduction of excessive expansion and contraction.

Thanks,

Ed
 

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Ed,

Polyurea is the product of a chemical reaction betweem an Isocyanate and an a amine-terminated polyol resin. Most set from a two-part heated and proportioned mix to a cured solid in six seconds or less. The one I use for roofing sets in 25-30 seconds at 50F on a warm substrate.

This is so much more than any coating....physical properties greater than ANY single ply on the market, mil for mil. Greater hardness, elongation, adhesion, and resiliency. All of this in a 100% seamless application. It cannot be beat.
 

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No reinforcement is needed, Ed, since it is stronger the thicker you build it, and sets instantly. You build up over seams, fasteners, penetrations, etc, to strengthen and reinforce.

Youre not too far away...I ll let you know when we are spraying and you can come check it out.
 

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User I can't find that file on my PC with the comparisons. I'll keep looking.

In the meantime,

I think we tend to talk about the sheets rather than the system many times. I have no problems with EPDM roofs, however it;'s the total system specifically ballasted systems I have problem with.

Details are terrible Field sheets are fine. It's all the perimeters, penetrations and those HVAC guys dropping panels all the time:shifty:

The majority of new construction commercial for GC's we do, is EPDM

The majority of buildings we do for bldg. owners, are SBS.

What's that tell ya?
Amen Brother spread the word.

We just need a little more love on the BUR/G side.
 

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if money wasnt an option and depending on if its new construction or a remodel .

New construction 3-ply BUR with a granulated Cap sheet
Remodel TPO
 
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