We are a wood floor contractor who often does site finished wood floors on commercial LEED projects, mostly in Texas.
The water based urethane we use states the following on the MSDS
VOLATILE ORGANIC COMPOUNDS (VOC Theoretical)
2.91 lb/gal 349 g/l Less Water and Federally Exempt Solvents
1.21 lb/gal 145 g/l Emitted VOC
1) Can you confirm which VOC amount above we are supposed to report?
2) Can you also confirm that we are correct in placing our clear urethane topcoat in the category of "clear wood finish" giving it a current LEED 2009 VOC limit of 350 g/l.?
If this is the case and we are using a stain that is not compliant because it exceeds the 250 g/l limit by usually less than 100 g/l, then is it realistic to use the shortcut method and have the urethane finish offset the stain in a VOC Budget calculation?
We have been told by a GC that its not that simple and we do not want to be the company causing them to have to run full blown VOC budgets.
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Jon Clifford
LEED-AP BD+CGREENSQUARE
LEEDuser Expert
323 thumbs up
April 22, 2015 - 12:29 am
LEED-2009 bases VOC limits for wood finishes either on SCAQMD-1113-2004 or on CARB-2007-SCM. These standards calculate VOC content “less water and exempt compounds.”
The answer to your second question depends on which of these two standards your project is using and on the characteristics of the urethane product.
If your product is opaque or semi-transparent and “formulated to change the color but not conceal the grain pattern or texture” of the substrate, it is a “Stain” with a 250g/L VOC limit under both SCAQMD & CARB.
By contrast, "Clear Wood Finishes" are formulated with natural or synthetic resins. SCAQMD defines three types: Varnishes, Sanding Sealers, and Lacquers (either clear or pigmented). For Lacquer (which dries without a chemical reaction), the SCAQMD VOC limit is 550g/L, but for the other two types (which dry by chemical reaction), the limit is 350g/L. However, if your project uses CARB (instead of SCAQMD), the VOC limit for all three types is only 275g/L.
Which of these types matches your product? If you can’t tell from reading the label, contact the manufacturer.
Finally, be aware that LEEDv4 may be coming your way on future projects. In v4, many VOC limits are lower still and additional requirements may apply.
Rick Farrell
Architect & Design ConsultantWoodwright Hardwood Floors
9 thumbs up
April 22, 2015 - 11:11 am
Thank you Jon,
Were are on the same page about the categories that our products fall in and the allowable limits for each.
Last question..?
When we use a stain over 250 VOC and want to suggest to the GC that they should run a VOC budget how do we best articulate that? We would like to point them to a very specific rule or possibly provide an example of the Shortcut method that we precalculate for them using another one of our products as the balancer..
Our goal is to make it easy for them not give them a job to do.
Jon Clifford
LEED-AP BD+CGREENSQUARE
LEEDuser Expert
323 thumbs up
April 23, 2015 - 8:00 pm
If a VOC budget gets triggered by just a handful of non-compliant coatings used in relatively small quantities, it is acceptable to use an abbreviated version of the budget that does not require quantifying every single coating used on the project. See the third question in LI#1822 and its response:
http://www.usgbc.org/leed-interpretations?keys=1822. This is easiest when all products used in the calculation come from one subcontractor (in this case, you).
However, using a VOC budget may not put you completely in the clear. If your project is pursing IEQc4.3, Low-Emitting Flooring, all wood floor finishes must comply with CARB or SCAQMD VOC limits, but I am not sure that IEQc4.3 allows VOC budgeting. (See http://www.leeduser.com/comment/redirect/56470.)
The BEST approach is to use only products that comply with ALL VOC limits and performance requirements specified by the project’s design team. I only use the budget approach if there are NO alternatives or when a questionable product already has slipped on-site. If this is the case, work not just with the GC, but also with the project’s LEED Administrator, for a solution that works with project goals.
Finally, really take a hard look at your 349g/L urethane product. Does the presence of urethane resins make it a varnish instead of a stain? Consult the manufacturer.