Single Ply Roof Membrane Adhesives

My first question is are these adhesives being used INSIDE the building. The point is INDOOR air quality, not outdoor. If they are outside the building envelope I don't think that they are considered. Much the same way that parking lot paint is treated.

Dwayne,

I don't think you're correct here. EQc4.1 just didn't have the space to list everything that Rule 1168 covers. I always go back to Rule 1168 when I have a question about the classification of an adhesive that is not clear in the reference guide.

While I agree that the adhesive put on the roof deck does have time to off-gass their VOC's, this does not matter to USGBC. Since the membrane goes over this, then the adhesive becomes 'inside the weatherproofing membrane' and hence must be compliant. If you ask your roof manufacturer, most have an alternative adhesive that meets the requirements and that will not void the roof warranty.

I have had USGBC question me on this in the past because this adhesive was not listed, but they knew what kind of roof we had. Fortunately, ours was compliant.

SImply put - the location of the adhesive in the weatherprrofing system sandwich controls whether we count it or not - if it is applied inside of whatever the barrier is you have to count it. That's why it's listed even in some ref guide tables for EQ 4.1

One of our peers at Perkins+Will just shared an official message from GBCI on this topic:

"This issue has only recently been explicitly taken-up by the IEQ Technical Advisory Group (TAG). Though the decision has not yet been officially published, we anticipate that the next release of rating system and/or reference guide addenda will clarify that the single-ply roofing adhesives and single-ply roof membrane sealants do not have to be considered when evaluating compliance with this credit as they are basically part of the weatherproofing system and they have a relatively small chance of impacting indoor air quality. All other categories of adhesives and sealants listed in the Requirements are still controlled by the VOC limits of this credit if they are applied "inside the weatherproofing system". That said, regardless of the application, it would be more in keeping with the Intent of this credit and LEED, in general, to find the lowest VOC option that meets the performance requirements for this application."

mara - in your post you say that this is an 'official message from GBCI'. has this been publised? or was it simply an 'official' emial from the IEQ TAG? i'm trying to nail down this information so i can follow this reasoning for a project i'm working on.

thanks.

The email Mara refers to was an email from GBCI in response to a project question sent in via LEED Online. Since USGBC/GBCI have not made an official, public statement about this topic, this email/post can't be taken as gospel; however, I would take it as a reliable indication of where the rating system is going.The next edition of LEED addenda is due this month; perhaps this will be covered.

All - there is no need to wait for clarification or to question it. Any adhesive for any purpose that is installed inside of the weatherproof barrier (can it withstand the rain without another layer?) MUST meet rule 1168. Qualified, experienced, LEED consultants know this and so do the quality roofing manufacturers. If you are in a position to advise clients on this type of strategy and you don't have the answer, I'm sorry but you don't have qualifed LEED folks involved where they should be.

Does the addenda posted 11-03-10 to IEQc4.,1 which added footnote 2 excluding adhesives that are integral to the roof waterproofing system, exclude the adhesive used to install the roof insulation, since the insulation is often required prior to installing the single ply membrane on top of the roof deck. Is the insulation considered part of the waterproofing system.

I would say the insulation is not part of the waterproofing system (it definitely seems to be within the system) and is subject to the credit requirements.But apparently there continues to be gray area for this credit, even with attempts to clarify it... anyone else have thoughts?

Since the addenda is specifically for LEED 2009 projects, how do you think this issue should be handled for LEED NC 2.2 projects? It seems like the same rationale should apply, however they do not appear to be publishing addenda for v2.2 anymore. I have some projects for which this is a sticky issue (ha ha!) since the low-VOC adhesives do not perform well when applied in cold weather. I'd like to be able to tell them that they can be excluded from consideration under EQc4.1. What do you guys think?

I think this should be applicable for 2.2 projects. However, to be sure you would probably need to submit a CIR. Or you could use the VOC budget method to be safe and save the expense of the CIR.

Hello Everyone,

I am sure that most of you have seen this, but for those that are just referencing this forum thread related to roofing sealants, please see below information from the updated GBD&C 2009 addendum. All comments are dated 11/03/2010.

471* Requirements table IEQc4.1 Low-Emitting Materials
– Adhesives and Sealants
In the “Sealants” section, remove the items “Nonmembrane roof, 300”
and “Single-ply roof membrane, 450”

471 Requirements IEQc4.1 Low-Emitting Materials
–Adhesives and Sealants
Add footnote number 2 at the end of the first bullet, “This table
excludes adhesives and sealants listed in Rule #1168 that are nonbuilding related or are integral to the roof waterproofing system.”

474 Table 1 IEQc4.1 Low-Emitting Materials
– Adhesives and Sealants
In the “Sealants” section, remove the items “Nonmembrane roof, 300”
and “Single-ply roof membrane, 450”

474 Table 1 IEQc4.1 Low-Emitting Materials
– Adhesives and Sealants
Below the table, insert the note:
This table excludes adhesives and sealants integral to the water-proofing system or that are not building related.

So based on this last post, would you still request the low VOC adhesive for an EPDM roof pursuing this credit under v2.2? We're in the northeast and the membrane is to be installed soon and the GC would like to use the standard adhesive provided by the manufacturer due to the current temperatures and premium for the low VOC adhesive. It looks like the standard adhesive exceeds the VOC limits, is within the membrane but outside the vapor barrier.

Paul, I do not think it is necessary to use a low-VOC roofing membrane, based on the feedback above from GBCI, and other discussions here.