Flat roof, PVC vs EPDM vs?

Just the thicker the product the more puncture resistent. Think of a 4ply tire vs. a 8ply. Plus it lays down nicer, no wrinkles! Doesnt flip over easy if you get a lil gust of wind when your gluing it down, & etc.

Plus a heat welded seam will never fail, eventhough epdm has come a long way. All non factory field seams fail eventually.

Generally speaking, saddles are used in flat roofs to direct water. Crickets would be the 1/2 saddles found mostly steep sloped roofs.

Ive never heard them called saddles but i`ll have to remember that. Ive worked up & down the eastcoast from Canada to Key West & never heard that. Idiot Savant, what part of the country you from?

Midwest. I mostly refer to things by the proper term instead of the slang terms. I get a lot of strange looks and WTF’s?

LOL.

[quote=“pondscum”]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?[/quote]

Lots of talk nationally about white roofs vs black roofs. Lots of data to support either white or black in just about any climate. Lots of guys here have lots of opinions on what is better. But you know what they say about opinions. For me I personally prefer the peace of mind that comes with thermoplastic heat welded seams. Though that peace of mind comes with more specialty equipment needed vs EPDM and an ever so slightly installation time vs epdm.

My opinion on the white vs black argument is this: If you are relying on the black roof to keep your building warm, you have bigger problems. In my climate, Chicago, where we have super cold and snowy winters and super hot and sunnys ummers a balanced system incorporates some kind of insulation and reflectivity. The insulation works year round and the reflectivity works in the summer. Ventilation is sometimes introduced into the mix as well.

EPDM is available white and black, though I think PVC is not available black, and is almost always white, and to the best of my knowledge the PVC I work with is only avaialble white.

I mentioned above about the peace of mind with heat welded seams. I find the flaw in EPDM to be the adhesives and tapes used to seal the membrane. The EPDM membrane its’self will last darned near forever, especially when you get into the thicker membranes. But the seams can begin to fail within 15 years. Infact the manufacturers acknowledge this, and that is why their 30 year specifications require double seaming, with seam tape and cover tape.

In either case, thermoset (epdm) or thermoplastic (tpo or pvc) I would opt for a middle grade 60 mil membrane. This thicker membrane will resist weathering affects longer than the 45/50 mil membranes. The cost increase upfront is insignifigant but you might squeeze 5 extra years out of the roof by going thicker now.

mechanically attached or fully adhered, for me, would vary ont he substrate type. If the substrate is wood or another nailable substrate I like mechanically attached systems. However if the substrate is of a type where fastening becomes a nuisane or cost prohibitive I prefer the fully adhered. Just keep in mind either will use the same membrane. The fully adhered may lay flatter than the mechanically attached, but unless you are dancing on the roof (and you shouldn’t be dancing on the roof), that shouldn’t mean anything.

I have seen both EPDM and PVC membrane roofs last a very long time. “30 years”. The EPDM needed work on redoeing all the uncured flashings and striping in the seams. The PVC roof that was installed in 1980 needed nothing , a little cleaning and it was compleatly weldable for the scuppers we were putting in. So I tend to prefer PVC as my premium roof. It also comes in colors. We just installed a grey membrane roof on sunny Cape Cod.

:o typo and i cant delete.)

3rd layer single-ply pvc 60m over polystyrene 4’. Any ideas? why happened that shrink?

I agree with Donl. Ask the question “do I have more heating days, or more cooling days throughout the year.” If you have more heating days then EPDM is the right choice. Granted, it may not quite live the lifespan of a properly done PVC roof, but it will save you on heating bills, and it should cost less upfront.

If you have more cooling days and money is no object, PVC is a no brainer.