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Reis Pearson
01-22-2008, 07:35 PM
This is a roofing material that I refer to in my reports as "Vinyl Rolled Roofing Material". Does someone know the technical name. It's white vinyl (suppose to be if it weren't covered in water) mostly seen on commercial buildings. See attached photo. Thanks in advance.

Jim Luttrall
01-22-2008, 07:38 PM
PVC product is common around here. Brilliant white when installed, very tough membrane.

Reis Pearson
01-22-2008, 07:41 PM
So do you refer to it as PVC membrane? How do you write it up?

Rick Hurst
01-22-2008, 07:51 PM
Reis,

That looks like one of the new infininty pools, I mean infinity roofs. ;)

rick

Jim Luttrall
01-22-2008, 08:50 PM
From the JM site:
PVC Single Ply Roofing System

Johns Manville PVC is a highly-engineered, flexible, thermoplastic membrane manufactured using an ultraviolet-resistant polyvinyl chloride and a DuPont™ Elvaloy® KEE (ketone ethylene ester) formulation. It provides excellent weathering characteristics, high tensile strength and long-term flexibility. It also exhibits excellent resistance to harsh chemicals and industrial pollutants.

Take your pick

Gunnar Alquist
01-22-2008, 11:21 PM
Might also be a polyurethane roof.

Eric Shuman
01-23-2008, 06:26 AM
The roof covering system may be a Thermoplastic Polyolefin (TPO) single ply membrane application. Which is probably just a variation or similar product to what Jim is speaking of. This is a popular roofing application in commercial buildings. I have also seen it recently installed in residential applications. The TPO system is considered to be a low maintenance long life product that is touted as being wind, rain and puncture resistant. It is also considered to improve energy efficiency as it is insulated and the white color reflects heat. The seams of the membrane are heat welded. The following link is one of many that can be found if you do a google search.


ASTM Standards for TPO Roofing Membranes (http://www.astm.org/SNEWS/AUGUST_2003/obeoli_aug03.html)

Jim Luttrall
01-23-2008, 07:35 AM
After seeing your photo on a bigger monitor, that does not look like the PVC that I have seen. What I have seen is shiny brilliant white. I don't know what your weather would do to it but around here it stays bright white with just a little dingy look after a few years.
That also appears to be more frequent seams.

Reis Pearson
01-23-2008, 07:39 AM
It actually started out white, but with the ponding water and the tree pollen it's looking a little worse for wear. I've wrote it up with excessive ponding, improper slope, refer to roofer. Thanks everyone for the posts! I've very much enjoyed the opportunity to discuss among professionals. Your feedback has been very helpful!:)

Rick Maday
01-23-2008, 12:45 PM
Reis,

That looks like one of the new infininty pools, I mean infinity roofs. ;)

rick

That was my first thought also! That's one heck of a picture!

Richard Moore
01-23-2008, 03:01 PM
I first saw TPO on a house last year. Had no idea what it was then but, fortunately, it had "Firestone" printed along all the seams so I was able to Google some info.

For a little more on the stuff, check out the "how-to" PDF's from the technical info button at Firestone (http://www.firestonebpe.com/roofing/ultraply/_en/)

Jerry Peck
01-23-2008, 07:44 PM
If it is white, it is most likely either EPDM with a white top layer (not as much in the last year or two, but before then) or TPO (which is white through and through).

PVC roofing is typically gray in color (although I have seen some 'whitish' PVC roofs).

What is the minimum slope of a roof in Seattle and how do they address ponding water? That roof even has a dam all the way around it.

Rick Hurst
01-23-2008, 08:28 PM
Reis,

Was there any type of drains or scuppers on this roof?

rick

Richard Moore
01-24-2008, 04:21 AM
I'm pretty sure this is Reis's roof (from 4 angles). 8th & Crockett, Reis? I can only make out a couple of downspouts but there may be more and/or internal drains.

Jerry...a lot of our "flat" roofed condo's have parapets or ridges. Some have scuppers and perimeter downspouts, others are sloped to drain back towards more centrally located drains, and there's often a mix of the two. Minimum slope as far as I'm concerned is anything that drains completely without ponding (or doesn't have stains from past chronic ponding). I've also had some with 2 to 3 inches of water due to tree debris clogged central drains.

How do they fix ponding around here on a flat roof? Good question! I assume the low spots have to be built up but I really don't know how a roofer would do that or what materials he would use. Anyone know?

When I do have access and see ponding on a condo roof, I report it as in need of repair, inform the client of the possible consequences (including assessments), and recommend they bring it to the attention of, and seek more info from, the HOA. I suspect that in most cases with older condos, nothing actually gets done until the next roofing or a serious leak. You can lead a HOA to water, etc, etc.

Jerry Peck
01-24-2008, 07:53 AM
Minimum slope for TPO, EPDM, PVC, etc., is typically 1/4" per foot, which means it is supposed to 'drain dry' with not standing or ponding water.

If the minimum slope is less than 1/4" per foot, and *IF* the roof still drains dry, that serves the same purpose ... but does not meet *MINIMUM* code.

Scupper and/or roof drains, *and*, emergency overflow scupper and/or roof drains are required for roofs which are not slope to drain off the roof, i.e, have parapet walls or other walls surrounding the roof.

Also, scuppers and roof drains are required to be at the low spot of the slope (the 1/4" per foot minimum slope). Being as there was ponding water: 1) there were no suppers or roof drains, 2) the scuppers or roof drains were in the wrong location, or 3) the scuppers or roof drains were clogged.

Richard, curious - where did you get those four photos of that roof?

Richard Moore
01-24-2008, 10:26 AM
The photos are from Microsoft Virtual Earth, which I can get to straight from my MS streets & trips mapping. It's like Google Earth (which is great) but for some metro areas you can also switch from satellite view to "Birdseye" view which are photos of the whole city taken from all four angles from a low flying plane. Very cool and occasionally handy.

I recognized Lake Union and the general area in the background of Reis's photo. Didn't take long to find the building.

Eric Shuman
01-24-2008, 12:19 PM
A few months ago I inspected a new commercial building with a TPO roof that had some areas of ponding. I listed it as a repair issue. The manufacturer of the TPO system provided the buyer with a warrranty certificate that stated that the warranty for the roof covering would cover the roof regardles of the water ponding issues. However, in my research I found that some other TPO manufacturers have a water ponding exclusion in their warranties. Caveat emptor.

Regardless, I consider standing or ponding water on low slope roofs to be a repair issue, particularly a roof that has a much water standing on it as the one in the photo in the original post.