Flat roof, PVC vs EPDM vs?

I’ve got a house in Colorado with a flat roof that needs replacing. It’s got BUR now but I’m looking to do a tear-off and replacement with single-ply membrane.

So far I’ve collected bids from two different roofers.

Roofer #1 recommends fully-adhered 60 mil EPDM, says black roofs are better for this climate and the black will also help evaporate any ponding water.

Roofer #2 recommends mechanically-fastened 50 mil IB roofing (PVC), says white roofs are better for this climate and their product has a lifetime guarantee that covers ponding water.

Roofer #1 can also put in modified bitumen for about the same price as EPDM, and Roofer #2 can also put in TPO for about 20% less than the IB. However, best as I can tell, those are inferior alternatives to the ones they recommend.

Any thoughts from the experts on this? Ignoring differences in price, etc, which is the better roofing material for this climate? Are the specs reasonable or should I try to get thicker membrane, etc? And, assuming other all other aspects of the two bids are the same, what approximate price differential would you expect between EPDM and PVC?

What will be below installed PVC or EPDM?

PVC bid says 1/4" SecuRock. EPDM bid says 1/4" Dens Deck.

I don’t know area or climate much. I would go for PVC. EPDM will evaporate because is creates heat too and that means heat to interior too.

When Im looking at a roof for replacement one of the first things I look for is whether the roof holds water, if it holds water, what are my options for getting rid of the ponding water? Sometimes drains can be installed, other times tapered insulation is needed.
Epdm and Pvc are both great membranes if installed correctly, however I have replaced both types where ponding water caused propblems , be it a seam eventually failed, screw backing out and puncturing membrane etc.

Both bids include installing some crickets to better direct water that’s now ponding along the parapet wall towards the scupper drains. That’s the issue that’s causing my present leak problem (there’s been so much sealer applied on the old roof around the scuppers that it’s actually preventing the water from getting out). So, yeah, fix the roof drainage and install a roof material that’s going to hold up better over time, is what I want.

If cost isn’t a deciding factor I would choose the IB pvc, a no brainer for me.

IB or another quality pvc membrane would be the best choice.

OK, that’s 3 votes in favor of the IB PVC, and none for the EPDM. Thanks guys! :slight_smile:

One more question… I’m told it will be about 8% more to upgrade from 50mil to 80mil IB PVC. Is it worth it? I’m confused that IB offers the same lifetime residential warranty on both but 15 vs 25 years for commercial. Do they figure few homeowners will stay in their houses more than 15 years? Is the 15 vs 25 a marketing gimmick to differentiate a “premium” product that doesn’t really outperform the regular one? Do they figure that the roofs are going to fail from one of the excluded kinds of damage (wind, hail, falling objects, flashing, etc) first anyway?

If u get a lifetime warranty why pay more.I didnt know IB gave lifetime on residential,but then again we can’t just go get it where I am and I know there are no certified IB installers anywhere real close to me.Everyone doing single ply here is epdm or tpo.I have installed lots of tpo,and 80 mil is quite noticably thicker and more durable.Thicker to me means more durable so it is a worthwhile investment(imo)even though the warranty is the same.It is your house,jmo.We do alot of residential single-ply and there is no manufacturers warranty on the products we use.It is solely a workmanship warranty.A roof is only as good as the installer…another reason to go IB,not just anybody with a ladder and a truck can install it.Is mod-bit banned where u are?I looooove torchin’ still my fave.Single ply is to much like arts and crafts to me.cut,glue,heat,roll…repeat :shock: But u gotta keep up with the Jones’

Stay with the 50 mil!!! Just my suggestion.

Well, here is a vote for EPDM. EPDM excels in cold weather areas. In fact it is the primary product used in most the of cold weather areas such as Alaska and the north east. In snow country a dark roof is the best color for thermal performance. In hot areas, go with white every time. If you have more heating days than cooling days, dark is the best roof.

Go with the thickest membrane you can afford. TPO is every bit as good as PVC and both will handle cold weather. If you are looking at PVC (such as IB mentioned) consider other brands such as Manville, Carlisle and GAF. I think you will save some money and the quality is every day just as good.

Just because in the 16yrs I have been using EPDM, I have never had a call back. Also, keep in mind when talking about ponding, EPDM is also used for shallow ponds. In Texas, most of my jobs are .045, but I have had request for .060. Back 10yrs ago, Mule Hide had a White,PVC coated EPDM. I looked at a large facility that the coating had began to come off. The rep told me they had problems with it and advised against using it, again. I’m sure they have improved it since.

With all that said & done my personal choice would be pvc or tpo, the thicker mil ofcourse. However, I wouldnt go with mechanically attached!#1) I would go with much thicker insul like; a 1" polyiso with a 1/2" densdeck cover sheet. Itll keep you cooler in the summer & warmer in the winter. Itll keep your cooling & heating bills down as well. #2) I would want my insul stuck down with instastick, fast100, olybond, or something like that. I would also want the membrane fully (glued) adhered down. This way the whole roof is fastener less, it looks prettier & you dont ever have to worry about a screw & plate backing out or missed screws & plates that some pee on was too lazy to back out & make sure the screw hits. If you love your home & plan on keeping it for many more years & dont want to replace the roof for 20 yrs. or more, trust me. Remember, no snow shoveling with metal shovels! :smiley:

Why would that be?

Why stay with the 50 mil, you asked? If it comes with a lifetime warranty, why pay 8 % more?

Ya, what is a lifetime to IB? What is a lifetime in the state of Colorado. Its just like epdm, would you rather have .045 or .060 on your flatroof? Especially in Colorado, you know he`ll be shoveling it.

At this point, I think I’m suffering from information overload. :? I think the bottom line is that I have to trust that the roofer who said this is their best option for a residential roof has experience doing it this way, knows what they’re doing, etc.

BTW, I live in a part of Colorado that typically doesn’t get much snow – at least, it’s nothing to what I was used to from living in Michigan and the Boston area for many years. OTOH, sometimes it gets very windy here, and I note IB’s “lifetime warranty” explicitly excludes wind damage.

IB is a really good and ethical company to deal with. I also really like FiberTite PVC membrane, very tough material. Duro-Last I even think makes a decent product. There premade curbs are thing I really love about them.