4specs.com    4specs.com Home Page

comparative chemical resistance of ro... Log Out | Topics | Search
Moderators | Register | Edit Profile

4specs Discussion Forum » Archive - Specifications Discussions #3 » comparative chemical resistance of roof membranes « Previous Next »

Author Message
Christopher E. Grimm, CSI, CCS, LEED®-AP, MAI, RLA
Senior Member
Username: tsugaguy

Post Number: 130
Registered: 06-2005
Posted on Tuesday, March 18, 2008 - 12:32 pm:   Edit PostDelete PostPrint Post

In terms of resistance to kitchen grease at exhaust vents, can anyone help rank the chemical resistance of various roofing membranes?

EPDM - appears to definitely be recommended against for kitchens, per MASTERSPEC Supporting Docs and what I have been told over the years.

Beyond that, which ones ARE good, and how can we know how good they are? Is there a standard test method for that?

TPO??? - Is mentioned as more resistant in Supporting Docs and NRCA, no detailed info of how resistant. Have been told before it is good for kitchen roofs, recently told the opposite, further digging says SOME TPO's might be good others might not. OK, test method and results please, anyone?

PVC - Considered better, still not sure how much better

CSPE - Also considered better, and again how much better? And since it is a thermoset which cures over time with exposure, it would be expected to be weaker at first. How does this factor in for INITIAL grease resistance, if different? How about mechanical workers moving equipment into place, if it hasn't cured yet?

Elvaloy (KEE) - On the upper end of the scale per DuPont marketing literature anyway, and NRCA seems to confirm, even mentions resistance to jet fuel.

Modified Bitumen - Is it somewhere in the middle of the list, or one of the better ones?

Is ASTM D 5538 the most applicable standard for TPO and others like it? I'm considering purchasing a copy in hopes of test info and categorization, but the abstract does not say.

If we begin to get any consensus, this would be a good page on the new CSI wiki.
Dave Metzger
Senior Member
Username: davemetzger

Post Number: 258
Registered: 07-2001
Posted on Tuesday, March 18, 2008 - 12:40 pm:   Edit PostDelete PostPrint Post

Masterspec Section 075323 noes that manufacturers of EPDM roofing offer offer epichlorohydrin or neoprene (varies with manufacturer) as a protection membrane over EPDM to resist hydrocarbons, non-aromatic solvents, grease, and oil
Lynn Javoroski CSI CCS LEED™ AP SCIP Affiliate
Senior Member
Username: lynn_javoroski

Post Number: 741
Registered: 07-2002
Posted on Tuesday, March 18, 2008 - 12:58 pm:   Edit PostDelete PostPrint Post

I've heard of placing a sacrificial sheet of whatever membrane being used around the exhaust area. If I'm doing an EPDM, I specify the epichlororhydrin sheet; if a TPO, I prefer the Elvaloy.
John Bunzick, CCS, CCCA, LEED AP
Senior Member
Username: bunzick

Post Number: 865
Registered: 03-2002
Posted on Tuesday, March 18, 2008 - 02:04 pm:   Edit PostDelete PostPrint Post

ASTM D5538 is a standard for "uniform, consensus nomenclature," i.e., definitions, according to ASTM, and is only 2 pages long. I don't think you'll find anything useful to your problem there.
D6878 is the standard for TPO roofing, but it does not include any testing for resistance to oil or grease.

Your best bet is probably to poll various manufacturers of each major system likely to suit your goal on resistance to oil. I don't know if there's a test method for it. Alternatively, as Dave suggests, it may be a matter of selectively addressing the problem in specific areas in consultation with a roofing manufacturer that you would otherwise prefer to specify for the project.

I'd be cautious about using a sacrificial sheet, lest the material absorb sufficient oil to affect the underlying roof. It would also require replacement at some point, and what if no one pays attention?

Topics | Last Day | Last Week | Tree View | Search | Help/Instructions | Program Credits Administration