I've understood the LEED EQc4.1-4.3 requirements, including the reference standards, and have pursued LEED credits for these numerous times over the past 10 years, but have more recently have had projects with nuances that have tugged at the limits of my understanding with regard to the following points (any help much appreciated):
1. Using adhesives and sealants that ultimately DEFINE the weather barrier. The LEED NC Ref Manual 20009 Ed. has listed, and attributed to SCAQMD 1168 effective 7/1/05, under "Sealants" two products that do not show in the LEEDuser table above; Nonmembrane Roof and Single-Ply Membrane. I finally have a project with membrane roofing on metal decking (no slab)and so must consider the installation products for the membrane roofing as not *outside"* the weather barrier, since these products make the weather barrier; any additional info on this? Should one include seam sealers but not flashing adhesives? Why don't these show in the LEEDuser table above? What about similar adhesives and sealants associated with the installation of the building envelope weather barrier and/or vapor barrier? What category would you use for those products?
2. Can anyone please confirm my reading of the SCAQMD tables? No one I know can confirm that the standard, Amended Jan 2005, and listing (for example) an " 7/1/05 Effective Date" limit of 550 g/L and a "Current VOC Limit of 650" to mean that, as of Jan 2005, the (then-)current limit is 650 and, as of July 2005, will be decreased to 500. It is very confusing to be reading something in 2012 that refers to "current" limit and then see that it is a higher content than that allowed in July 2005.
3. The above VOC limit numbers are from a SCAMD file that I saved in Feb 2012. I have another copy of the file that I saved in July 2008 and it had another column for even lower allowable content dated Jan 2007, which the more recent file does not have. BOTH of these have on the first page a list of amendment dates that culimnates with Jan 7, 2005 date; how does one know what the most recent date is, and how would anyone verify if the documents have the same appearance?
4. Over the past 10 years, I've seen an explosion of products listing VOC content, but also a total disappearance of any companies recognizing the "less water" requirement; SOME of those at least reference the SCAQMD std but a greater number do not. I have always demanded demonstration of compliance as required by the bid documents, but when the MR's printed product Data describes a g/L VOC limit, I usually only get strange (and hostile) looks from contractors when I ask for confirmation that this is "less water" because the folks that THEY ask at the MFR don't have a clue, and the conversation goes nowhere. Any idea of how prevalent Green Washing is?
John-David Hutchison, LEED AP BD+C, PMP
Sustainability ManagerBGIS
LEEDuser Expert
166 thumbs up
November 26, 2012 - 11:49 am
1) It depends on what you are using, but I have always followed that the membranes we generally use as a rule are modified bituminous which are applied " before" the membrane as a sealant primer.
Therefore, it is inside the weather/vapour barrier.
Therefore I follow:
(41) MODIFIED BITUMINOUS PRIMER consist of bituminous materials, and a high flash solvent used to prepare a surface by (1) improving the adhesion and (2) absorbing dust from the surface for adhesive, or flashing cement bitumen membrane.
and/ or:
(71) SINGLE-PLY ROOF MEMBRANE ADHESIVE is any adhesive sealant to be used for the installation or repair of single-ply roof membrane. Installation includes, but is not limited to attaching the edge of the membrane to the edge of the roof and applying flashings to vents, pipes, or
ducts that protrude through the membrane.
and/ or
(72) SINGLE-PLY ROOF MEMBRANE SEALANT is any sealant to be used
for the installation or repair of single-ply roof membrane to the edge of the roof and applying flashings to vents, pipes, or ducts that protrude through the membrane.
2) If you do not have already, I highly recommend downloading the full Rules 1113 & 1168 from: http://www.aqmd.gov/
It makes everything much clearer.
4) (you have no 3) When in doubt, I generally email or call the manufacturer myself. If they want to sell in California, they'll have the info and they need to have "a VOC content in excess of 250 g/L less water and less exempt compounds"
I have found if they don't have the info - they don't comply.
I know it's a lot of work, but I would recommend that like every architectural product in the spec, it needs to be approved before it's used.
I hope this helps.