Flat roof question

[Greg W. Mathias, CCHI]

I have looked a alot of different systems but have never seen this style. The membrane was not rubber but instead a weaved thin plastic similar to lumber wrap. Has anyone seen this and what is the service life of a roof like this??

[Barry Adair]

imo from photos ballast applied tpo

http://www.nrc-cnrc.gc.ca/eng/ibp/ir.../ctus-n30.html

termination at drains is wrong, you probably caught that ;~))

[Larry D. Kage]

Originally Posted by badair

imo from photos ballast applied tpo

http://www.nrc-cnrc.gc.ca/eng/ibp/ir.../ctus-n30.html

termination at drains is wrong, you probably caught that ;~))

That looks like it...but, man, Greg has his work cut out for him removing the balast to inspect it, eh?


From above site:

Properly installed TPO roof systems have service lives ranging from about 10 to 20 years, depending on the type of installation. Full removal of the existing roof, the amount of slope the roof has, weather conditions, as well as several other criteria contribute to the longevity of a roof's service life. Typically, if you remove an old roof down to the deck before installing a new one, then the new roof will last longer. Also, the steeper the slope and the less severe the weather conditions, the longer a roof will last. High winds and hail can do a roof in rather quickly.
But remember, the number one ingredient to a good roof system is proper installation

[Greg W. Mathias, CCHI]

Originally Posted by badair

imo from photos ballast applied tpo

http://www.nrc-cnrc.gc.ca/eng/ibp/ir.../ctus-n30.html

termination at drains is wrong, you probably caught that ;~))

I did catch the drain being wrong. There are four of them and all of them need to be repaired. Thanks for the info on the roor system

[Greg W. Mathias, CCHI]

The only thing bothering me still is that the seams are not welded but overlapped. Wondering if the membrane is only being used as protection and there is a membrane under the foam. It did look like plastic was layed down under the foam?? Roof is 24 years old but seems to be in great condition.

[Kenton H. Shepard, CMI]

Man, that looks like synthetic underlayment to me, not meant for this application but for sloped roofs and the manufacturers usually list specific overlap requirements for low-slope. This is not even low-slope but basically flat.
Here are some photos of synthetic underlayment for comparison.

Evaluation by a qualified roofing contractor.

[Greg W. Mathias, CCHI]

Originally Posted by kshepard

Man, that looks like synthetic underlayment to me, not meant for this application but for sloped roofs and the manufacturers usually list specific overlap requirements for low-slope. This is not even low-slope but basically flat.
Here are some photos of synthetic underlayment for comparison.

Evaluation by a qualified roofing contractor.

The top layer is more like a lumber wrap. I needed to go back today so I went back to take another look. I found a bitimous coating on the concrete surface, then 6mil Poly, 4" extruded foam, plastic weaved wrap and then the ballast. Each layer protects the next. should be a long lasting roof.
Any thoughts??

[Kenton H. Shepard, CMI]

It's beyond my level of expertise, I specialize in steep-slope roofing materials.

[Greg W. Mathias, CCHI]

Originally Posted by kshepard

It's beyond my level of expertise, I specialize in steep-slope roofing materials.

No Problem Kenton, I have never seen it myself and I thought I had seen them all.

[Mark A. Timpani, CMI]

Ask Dale Duffy

[Greg W. Mathias, CCHI]

Originally Posted by mtimpani

Ask Dale Duffy

I would but not sure who that is and could not find him on the forum??

[David A. Andersen]

What do you think about it?

Your the one working at an engineering firm...

[Linas Dapkus]

Originally Posted by dandersen

What do you think about it?

Your the one working at an engineering firm...

I think he's ready for CMI.

[David A. Andersen]

I think he's "undercover CMI"!

[Kenton H. Shepard, CMI]

I'm totally convinced that that roof is sort of granular.