Flat Roof Material

wadswob

Anyone have input on the best material to use on a flat roof? I am working on a new house that will have a 3/12 metal roof over half of it and a flat (1/4 in/ft) roof over the other half (about 500 sq ft). We are interested in getting the house "green certified" and I am interested in what people consider the best material to use both from a waterproofing standpoint and a green standpoint. PVC and EPDM are the two materials that have been suggested.

Grumpy

PVC is reflective thus more "green" imo. If you're thinking epdm and green I bet you're thinking white epdm, which I do not have any confidence in. Better off with the PVC IMO. PVC has heat welded seams, epdm has adhesive seams. WHile the epdm and tpo membranes will be around forever and take thousands of years to biodegrade, the seams and penetrations will be the weak point. I always favor a heat welded seam over a cold adhesive seam anyday.

AaronB.

Soy based polyurethane foam with a white reflective coating.

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Grumpy

Can you put spray foam on a 3/12 Aaron?

BTW I spoke with that Lady in Chicago on Saturday and someone did a real good job talking her out of foam so I didn't want to argue. She was settled on the PVC as her choice roofing membrane and rather than argue at 8:30 Am Saturday morning I just rolled with the punches and agreed with her.

JR&R

Are foam roofs covered by insurance up north? A lot of companies in Texas have stopped covering foam, although there are still many being applied.

theflynner

I've been doing large commerical flat roofs for 22 years. I usually recommd an asphalt built-up roof for the quality, but it's too messy for a residential job.

When someone asks me what to use for a small roof, I usually recommend Fully-adhering EPDM Rubber. Most all seaming problems with EPDM have been reduced with the use of seaming tape in lieu of splice adhesive.

TPO (thermoplastic) might be as good, but has not been time tested. It may reflect the sun better, but if you have a lot if insulation, (like you should), and your house is north of Wyoming - Iowa - Indiana, any energy savings is offset.

The most critical thing is orkmanship and doing the details correctly. The flashings should be 8" high above roof surface, and have at least 1/4" slope.

Don't - under any conditions -consider a sprayed urathane roof. It is the worst roofing system on the market. I've never seen one that has lasted 8 years without major problems. I don't like Cheeze-Wiz on my crackers, and you won't like it on your home.

Tell your contractor you want a fully-adhered 60-mil thick EPDM Rubber or TPO/PVC roof. When he is done, perform a heavy water test with a sprinkler.

John F. in Minnesota

Grumpy

JR&R is that due to the massive hail storms you have there in Texas?

Red Adobe

Hail and extreme heat. The roof next to my shop was foamed 6 years ago and its failing already even with the white coating...... The co that did it is long gone and never told him they had to be recoated every 5 years or so
the owner told me the other day he wished hed have listened to me and did his to match my low sloped metal

EIFS wall systems even fail here from time to time I saw a building with 10x20 section of brown, mesh, and finish blow off a building last spring

If you have to go flat then id go epdm.....

I still like framing in a low slope and metal , I like the 50+ yrs you get out of it

AaronB.

What was the cause of that particular failure? How did the hail hurt the foam, and what does extreme heat have to do with a foam roof failing?

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Free roof inspections within 12 miles of our locale.

AaronB.

Are you saying that hail will not damage EPDM or destroy a metal roof? If that's what youre saying....

__________________
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Seamless Industrial and Commercial Roofing Systems, Residential Repair. For Those That Demand Quality!
Free roof inspections within 12 miles of our locale.

JR&R

Grumpy,

I am pretty sure that is the reason. From what I understand they claim it is not an approved roof covering.

I just renewed my insurance on a commercial building that used to have foam, and the above reason was given.

Aaron makes a good point, but most roofing contractor around here don't consider it a true roofing system.

I hate to take a position on the matter because there are some pros to foam, but the only time I have seen it used is to cover existing sin. I really think this is the reason insurance companies quit covering it. In the long run it cost more to replace.

AaronB.

New Orleans Superdome...

SOOOO many haven't a clue, which is the most likely reason they speak such roofing blasphemy... pure ignorance.

__________________
http://www.roseroofing.net/
Seamless Industrial and Commercial Roofing Systems, Residential Repair. For Those That Demand Quality!
Free roof inspections within 12 miles of our locale.

AaronB.

Can't blame 'em though... it is human nature to fear what we don't know...

__________________
http://www.roseroofing.net/
Seamless Industrial and Commercial Roofing Systems, Residential Repair. For Those That Demand Quality!
Free roof inspections within 12 miles of our locale.

Grumpy

I do not think there are any one size fits all roofing solutions. foam, like any roofing system, has it's pros and cons and has it's place in the market. It's not for every building. I mentioned once that all the foam roofs I have seen were complete chit, I did mention that in my novice foam opinion it was actually due to installation carelessness, but he didn't read that part and blew up on me, until I pointed out it was installation error once again. The problem I have if I were to only promote one type of roofing system is if the customer doesn't beleive in it I have no backup plan. Like you said Aaron, people fear what they do not know.

I have told this story once before but I had an elderly lady once tell me the roof I was proposing would not work because it is white. Her roof is black, it's always been black, ever roof she ever lived under was black, it was black when her deceased husband was patching it and in her mind if the water is to stay out the roof MUST be black or it will leak. I stopped trying to understand people, and started trying to roll with the punches at that time. Just like I said with the Lady last week end on the foam roof above; if foam were all I was selling I'd have no recourse. Her mind was made up. Smile and nod, ask her what she would prefer, and then sell her that. I'm so worn out of fighting uphill battles for no good reason.