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TPO or PVC flat roofing ?? Which is best?

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78K views 43 replies 20 participants last post by  A&E Exteriors  
K
#1 ·
Hello- I am in some RE investment groups and one of our members had this question-
**************
TPO (Thermoplastic Membrane Roofing) COOL ROOF SYSTEM or Polyvinyl Chloride---
Does anyone within our REI group have any first hand knowledge of this material being used on their multifamily property?
If so, please give me your honest assesment on its merits. Is it worth it for a flat roof?
I have considered a couple of properties but with flat roofs, my underwrites are a bit sceptical.
Thank you in advance to whomever can provide me with some feedback on either this material or something similar that is beyond the traditional tar covering.
Sincerely,
John Gallion
****************

If anyone has any expertise in this, please PM me or post on this thread. I'll forward that right to this guy. Thanks,
Ken
 
#43 ·
rodeo said:
I put pvc (durolast) on my apt complex flat roof and I regret it. Its overpriced and proprietary. I'd go with epdm if I could do it over again. Better yet ctp bur but thats another subject. Who installed it is much more important.
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Duro last was tpo and was garbage, I'm pretty sure it was only .035 mil, too thin , I use .060 mill tpo and have used it to line reclamation ponds at mines in Wyoming, it's great PVC is better and lasts 30% longer at 15% higher cost ,
 
R
#3 ·
I install all types of roofing but think PVC membrane is the best single ply on the market. TPO is still unproven, EPDM is good for a low budget but the seams and flashing reley on glues and tapes that can break down over time.
Some PVC like IB have colors available and offer a 25 year warrany on commercial and lifetime on residential. Dura Last , Sarnafil,Fibertite are all also very good but as with any roof its only as good as the crew that installs it. You may want to check out. http://www.youtube.com/watch?v=OcNuHrgujPQ or http://www.youtube.com/watch?v=qa0ezELeX64


RooferJim
www.jbennetteroofing.com
 
L
#5 ·
I consider the PVC sheet made by Sarnafil to be one of the best available single ply membranes on the market. I base that opinion on the fact that they have been making their own sheet for a long time without changing the chemical formulation and that they have not had the membrane failure issues that have troubled so many in the industry.

TPO (and some early PVC's) has had some issues with membrane degradation/deterioration, especially out here in CA. The TPO mfg's say it was only in ponding areas, or where the sun reflected off a unit or a south facing wall and cooked the sheet or where the welder toasted the sheet along the walk pads or this or that. Bottom line is that they have had issues which caused their membrane to fall apart. If you can get them to talk about it they will tell you its all fixed now. Yep. Right. Uh-huh. :whistling

(FWIW, when TPO first started coming into the market it was touted as having the sheet stability of EPDM [ EPDM's + and PVC -] with the security of welded/fused seams of PVC systems [PVC+ and EPDM-])

However, in 2 weeks my firm is going to start installing a 2,000 square TPO roof because its the cheapest thing out there. I would rather install Sarnafil but the owner wants the cheapest roof with a 15-year warranty and Sarnafil cant come close on the price. However, the TPO will be lucky to last 15 years with the mfg. probably nursing it along the last couple of warranty years whereas the Sarnafil roof would be good for at least 20-25 years.

I dont think Sarnafil really likes residential work as their warranties are very limited for residences. Depending on the type of dwelling IB or Duro Last may provide better warranties.

As has been mentioned already, any roof is only as good as the installer. We recently replaced a 1 year old single ply roof originally installed by someone else due to continuing leaks caused by extremely poor workmanship. No membrane problems, just workmanship issues. You need to make sure that the roofer knows his stuff with the system that he is installing.
 
L
#7 ·
The 1 yr. old mechanically attached single ply roof that we just replaced was supposedly done by a roofer doing his 1st single ply job. I didnt get the details as when we were on the job the owner, architect, GC, and lawyers and experts were all there watching so I wasnt in a question asking mood. (I took a bunch of pics with a new camera but lost them due to operator error:sad:)

The biggest problem contributing to the leaks were cold welds. You usually get cold welds when you use the wrong settings on a robotic welder. With a cold weld, the membrane seam will weld together and will visually look good but the seam will come apart when you test a sample of the seam. That is why you ALWAYS have to take destructive seam samples when using a robot welder. I didnt really see and voids or fishmouths but then I wasnt looking for them. By evidence of the mold and stains on the underlying insulation, there were quite a number of leaks.

Although probably not contributing to the leaks, one thing I had never seen before while removing the old roof was that we could rip the membrane along the seam. I have never really been able to "tear" a single ply membrane due to the reinforcing scrim. But in this case we could start at the end of a sheet and make a small cut (and many times didnt even make a cut) in the sheet right along the edge of the overlying sheet and then just rip the sheet up. The sheet would rip right along the edge over the entire length. It made me wonder about the overall intergity of the sheet. This may have been caused by the the robot welder cooking the sheet or something but I never did really figure it out.

There was a layer of Dens Deck and 2 layers of iso under the membrane. There were some larger gaps of about 3/4" in the top layer of Dens Deck and there were huge gaps (up to 12" in the bottom layer) in the iso. In fact, in one area they had used small chunks of iso as pedestals to support the 2nd layer of iso. They also installed the insulation plates in the literal corners of the Dens deck so that the plate would cover the corners of the 2 or 3 adjacent boards. It was a new fastening pattern that I had never seen ! These things didnt really contribute to the leaks but were indicative of a really crappy install job overall. It supposedly took the original roofer "weeks and weeks and weeks" to install the original roof while we got the thing done in 6 days with 8 guys. There was a heavy rain 2 days after we finished and there were no leaks in the system!:clap:

The original roofer has supposedly gone out of business (surprise!) leaving the GC holding the bag on this. I dont know why the roof system manufacturer didnt step up to the plate but its one I am not approved with and I dont know any details on that end. So I guess the lesson of the day, among others, is to use a reputable roofer installing a system that he is familiar with from a reputable manufacturer. It doesnt really matter if its a PVC or TPO sheet if the installer cant put it down right.
 
1
#8 ·
In my opion TPO is better then PVC, with that being said most pvc's around here are duralast roofs and they are real POS's, 5 years max. We have put on TPO and EPDM roofing for a very long time. We have had very good luck with EPDM and TPO. I am not talking about ballasted mechanically attached glued seam 45 mil EPDM either. Fully adherd EPDM with positive drainage (as with any roof). I have heard about the problems with TPO and sun reflecting off windows and such. My first choice would be BUR, you cant go wrong well unless you hire someone who doesnt know how to roof. Thats the big thing find a good contractor and stick with them, most of the time low bid will only get you sub par work and headaches down the road. With TPO and PVC you can sell them on the "green roof" idea. You can also get up to a 20 yr warranty with either system with most manufactures that we deal with. You can get a 30 with a 90 mil EPDM but you most people will not like the cost. Bur 20 or so years, but as long as you dont have people up their poking holes (think HVAC) you can get well over 20 with a properly installed system. Good luck just find a good experianced flat roofer and you should be fine.
 
1
#11 ·
Debbie0 said:
Can I still put PCV on EPDM after EPDM is no longer working? OR I should first remove EPDM and only then install a PCV roof coating..
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Depends, here you can have only a total of 2 roofs. So if the EPDM was a recover over a BUR then no. If there is nothing under the EPDM aside from insulation, then yes. You will have to seperate the layers IE cover board or more ISO/insulation. In our experiance we have noticed that TPO and PVC will condinsate with the big temp swings. So a cover board may not be a great thing to use as fiber board will be come a big pile of mush. Maybe use a dens deck.
 
L
#10 ·
1985GT - What specifically were the problems with the Duro Last membrane? Were they installation issues or membrane performance issues? Their membrane seems to be pretty good as I have not personally seen or heard of any problems. I dont care for their polymer term bars and fascia pieces and I dont really like how everything is a bit loose and baggy from prefabbing, but there membrane seems to hold up pretty well.

Debbie0 - No you cannot install a PVC membrane over EPDM without some type of separator. PVC is not suppose to touch EPDM as the EPDM is corrosive to the PVC.
 
1
#13 ·
Installation issues with duralast are almost a given in our area as only a few companies will install them. We have also seen the PVC shatter with hail and cold temps. I belive this is more because of the thickness of the PVC and age. I think duralast atleast the ones we have seen are 32 mill. I do not know if they offer a thicker sheet or not. I would venture that PCV that thicker would hold up better. Plus I think think they look very poor. Using field sheet to wrap a soil stack and just bunching up corners on a wall look piss poor IMHO. Show a real lack of pride in one's work and it goes to show that cheap is not good.

Now I only have seen duralast roofs here in nebraska/iowa area, I have no idea if in other areas they are installed better and or hold up better. Just wanted to say that before someone takes it the wrong way.
 
W
#20 ·
Thermoplastic polyolefin, or TPO, is the fastest-growing segment of the commercial and industrial roofing industries. Fueling this growth is the increased use of TPO in southern climates, where reflective, energy-efficient and cool roof products are becoming the norm.

Polyvinyl Chloride (PVC) is a trusted membrane that has been performing admirably for decades in the European market and in North America. PVC also offers excellent resistance to rooftop chemicals, including acids, oils and greases.

Typically PVC would be installed at restaurants, industrial applications, etc. There really doesn't seem to be a reason for you to incur the additional cost with the application you have described. Therefore, we would recommend a TPO membrane.

There are many different manufacturers of TPO and each one has different quality control procedures and requirements for contractors to become "authorized applicators". We would recommend Carlisle. They offer warranties ranging from 15-30 yrs. Many of which are NDL (no dollar limit), total system warranties.

Whitco Roofing, Inc.
 
G
#24 ·
TPO and PVC and similiar roof membrane but not even close to being the same. I personally install more TPO than PVC, but we do install both. There have been some issues with generation one TPO, as with all first generation products including appliances and automobiles. I beelive those bugs have been worked out but only time will tell. PVC has a better reputation because it has been on the market longer (since the 60's) so it's had more time to work out the bugs.

Overall the spcifications and warranty durations for TPO & PVC are very much the same. If a customer says to me they want the best roof I steer them towards PVC. If they said they want a good roof for a moderate price then TPO is my answer. TPO costs less than PVC, but not much. Not every customer has a PVC budget however.

From an installation point of view, all things aside I personally prefer working with TPO over PVC. I just find it easier to weld, no smoke in my face etc... However one thing I like about PVC is the bleedout that you really don't get with TPO. With that bleedout you know it's stuck good and tight.

The two are not the same but they are close and I am confident installing either. I know some roofers who won't touch TPO and that's their decision. I offer both and give the customer the information they need to decide. I'm no one trick pony.
 
P
#26 ·
I cannot stand TPO! To me it is the new flavor of the month. I love how the companies offer 20 year warranties, when they do not even know if their products will last that long. Most of the TPO manufacturers are on their 3rd or 4th formulas. TPO is very difficult to patch/repair. It is easy to get cold welds, which if not checked thoroughly will lead to roof failure.
I prefer PVC, and definitely Sarnafil. The PVC has a bleedout when installed, and that lets you know you have a nice firm seal. Additionally, they only sell to select applicators, which allows them to control who is putting on their product, and thus hopefully, means the customer gets a quality install. I actually got the pleasure on going on a plant tour at their plant. Saw the nuts and bolts, and boy what a system the have there. Also got to see a roof of theirs that had been in place for 30 years. Can Tpo say that?
As for Epdm, it is a good product, though if you want a white one...run away. White EPDM is more expensive, and also a huge failure to the industry. As for standard black epdm, again, a good product, but as a buyer, my concern would be the tapes and adhesives on the seams. Those break down over time, and must be figured into your maintenance costs. It's easy to see why, rubber, like alot of products will expand and contract in heat and cold weather, this can cause the material to develop an alligator like look (crating, etc).
As for BUR, it is similar to EPDM, but for those that have a concern about the smoke from PVC, try being exposed to asphalt and tar. I will pass
In regard to a BUR,
 
S
#33 · (Edited)
Good Luck with TPO

Spot on!

Look, I have installed 100's of thousands of square feet of both TPO and PVC and can fully appreciate what TPO does for your bottom line and profit margins, as it is cheaper than PVC. The dilemma I have is that I know from experience that TPO roofs fail at a much higher rate than PVC (have replaced 100's of square feet of 7 years or less TPO with PVC). Thjey look similar and that is why most customers will go with whatever the contractor says, and if the profit margin is the only thing driving the contractor to sell TPO, then that contractor is doing his customer a disservice. I'm sure many contractors could care less since many will be gone in 5 years or close shop and re-open under another name, so why not grab the money and go? Seems to work for Wall ST (i digress).

In addition, I have installed many different PVC membranes. there are really only 5 types of PVC Sarnafil, Duro-Last, Fibertite and JM and all the others. The prvious 4 mentioned all manaufacture their own material and have been doing so for 30-40+ years. the other brands like Carlisle, Versico (private labeled Carlise), WeatherBond, IB and Gaf/Elk all come off the same assembly line and plant, whether they all have different formulations or not, it is basically all the same material (back filled with large er scrims).

I am certified through IB, Duro-Last and Sarnafil and would sell Duro-Last over any of them for many reasons, but mostly because they have the best warranties in the market. None of the other manufacturers can beat the no-dollar limit NDl plus consequential damage that duro-Last includes in the price of it's materials...nobody, not even Sarnafil. If you want to protect your clients investment, then Duro-Last is the way to go. If you want to maximize your profits, then go with TPO.

I personally have no idea if I will be in business for 20 years, therefor I make every effort I can to ensure that my clients have a manufacturer that will cover my workmanship in addition to their material for the life of the warranty.

If you own a commercial building and are researching these materials, don't be fooled by the sales pitch, look at the warranties closely, because in the end that's all that matters.

For flat roofs tapered roof systems with Duro-Last are the best. Some contractors ***** and moan because of the costs affiliated with Duro-Last (have to use everything Duro-Last from screws to caulking to the underwear you wear), it can be a pain to have to order something and delay a project for a drain or some screws, but in the end, if installed right (which an inspector makes sure it is), is the best system for your client. I have nothing bad to say about Sarnafil or Fibertite both very good products, but the bashing of Duro-Last on this forum is either sour grapes or contractors who don't know what they are doing (either pricing it out or installing it)

good luck everyone!






Image
 
S
#27 ·
I thought EPDM was the Yugo of membranes ... maybe that's just the thin cheap stuff. Like anything else, you get what you pay for. If I were installing something on my own flat roof, it'd be PVC, and I'd probably go with fully adhered over tapered cover board.

There is some spec for high wind lift zones that says mechanically attached is more resistant, but I don't believe it - unless the adhesive doesn't bond. I'm the kind of guy that would go way overkill and do both really :D Glued and screwed!!! LMFAO!
 
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