Flat roof question: FLEX, TPO, EPDM and

Hi roofing experts,
I’m a home owner with an (almost) flat roof (I believe it’s 1/12 grade). We currently have an old tar and gravel top that needs replacing, and we’ve been considering membrane options as well as a straight tar and gravel replacement. I should mention that our house is on the (west) side of a mountain, and is subject to lots of sun, wind, and (in the winter) snow.

We’ve been hearing about Flex (“elvaloy kee” ?) and fibertite membranes, and their main selling points appear to be energy efficiency, ease of maintainence and a “lifetime warranty” (although other posts on this forum indicate that this warranty promise is essentially meaningless).

Most roofers we’ve talked with recommend TPO or Flex, (but one inspector also threw in EPDM). I searched the forum and found some discussions on SPF as well, but nothing about flex).

My question: In general, for a residential flat roof, given that we wouldn’t want to be replacing the roof in a few years, what material (TPO, EPDM, FLex, SPF) provides the best value for money. I understand that much of this depends on the installer skill level, and I’m merely trying to understand the tradeoffs between the various materials (since we’re getting very confused).

I’d appreciate any help you experts can provide.

SPF with a silicone coat would be my recommendation. Value for money wise you’ll get your money back on energy savings in a few yrs and with care and attention, (maintenance)it will outlast almost anything else. Make sure though that the installer has accreditation. SPF has for many, a bad reputation but this is due to defective installation NOT the product. Personally I don’t like the TPO/PVC systems. A cigarette butt or a bird with a chicken bone will drain your bank account.

Having been putting on pvc ,tpo and epdm for over 25 yrs i would say a 80 mil flex or ib roofing system both pvc these are also a great system if trees are around your home.Make sure that some sort of ice &snow guards are present if any door walls are underneath.Both of these systems will give you a lifetime res warranty epdm is a great product but if you want a true heat and cooling roofing system pvc or tpo.Epdm in 60 mil or 90 mil will work but i would go with pvc.

Why is that ? is the PVC material that fragile ? as an aside, our roofer was recommending 45 mil flex, not the 80mil

flex is junk. it shrinks and 4-5 yrs down the road you’ll end up replacing it.fibertite is a great system as are most tpo,s. you want to go thicker than .045 mil. get quotes for all systems and just figure which suites your needs the best. they all have pluses and minuses. and a bird with a chicken bone is a chicken not an account drainer.

and krakker…any cigarette made in the us has an additive to the tobbacco that only allows it to burn for 30 seconds.well below the 73 second ember test for tpo and 86 second for fibertite.

Any 45 mil epdm,pvc or tpo installed properly should last for 20 plus years with proper maintenance.
Proper installation is key.

Well then Roofboss I guess every time I went and burnt a patch over a hole made from guests flicking their cigarette butts over the balcony (on to a brand new TPO roof) at a hotel in Tampa was all a waste of time. And when I leave a Camel in the ash tray for too long there’s only a filter that remains.
Birds, especially gulls will take trash from the ground up onto the peace and quiet of a roof and peck away, badly aimed pecks will do a number on TPO,PVC, EPDM, and SPF. Seen it many times.

Gotta watch out for those smoking birds…yea.

True about the birds. They can wreak havoc on your roof. Warranties are bs. And matainence on a roof is a must. So even though you may choose a good membrane system you have to figure out the matainence cost throughout the life of the roof. That can cost you more then the system if you don’t keep up with it every year or so and will void that lifetime warranty that looks so good.

try mearly “welding” your patches. if you burn them on they probably arent working that well

Never had one lift yet.

in my experience (10 years) fibertite is not worth it.
I would go with a fully adhered 60mil TPO or non-reinforced EPDM if the roof is not that large.
PVC is also a good option. Sarnafil is a great membrane.
TPO or EPDM would be cost less and TPO or PVC would be your best bet for reflectivity

put the rubber to it if properly installed,you will have no more problems.

For the climate area you mention I would first consider EPDM (Rubber) membrane as the best membrane in snow areas. It is a black membrane and is perfect for snow country. It will take direct sun without a problem. To get the most bang for your buck I would recommend at least 60 mil and even thicker if you can handle the cost. (That goes for the Flex membrane too).
If you want a reflective membrane (white) I would recommend the TPO membrane. Environmentally clean, no plasticizers or chlorine. Again, go with at least 60 mil. TPO will give you the most for your money…it will be significantly less than Flex. Since you are shoveling snow, install a fully adhered system over insulation.

i like local veteran installers using local products.
what does your neighboors house have on it?
have they had trouble with a certain product?


I am not sure why a cigarette butt or chicken bone would hurt a PVC membrane. Our PVC membrane (Sarnafil) is self extinguishing…cigarette will mearly leave a black mark. I actually just went outside and dropped a lit cigarette to a .48 mil sample and it didn’t burn a hole in it however it left some brown marks Being a 40 year company we have real world proof our roofs will last 25-30+ depending upon the thickness. Our membrane was rated the best in reflectivity 86% (EnergyStar starts at 60%) We also can recycle 100% of our membrane. I am confident that bang for your buck you can’t beat a PVC roof.

Here is a site where you can see the fire test videos by an independent agency…PVC vs TPT vs EPDM

What do you want over your house?