Engineered wood products

I recommend submitting this question to USGBC customer service, since it is not addressed in the reference guide. Exposed engineered wood products are not listed under ceilings, but exposed concrete and steel are specifically excluded as inherently non-emitting ceilings. Therefore I think ceilings is the likely category and that you will end up following the General Emissions Evaluation.

I don't know the answer either. The CARB definition of "composite wood products" specifically excludes structural stuff, but the LEED credit overall says it applies to everything inside the water-proofing barrier. Did you ever get a response, Christine? 

That would make sense, thanks! It would be nice to see a clarification from GBCI.

Agreed. I forwarded it along. Let's see what they say.

Hi Michelle, Did you get any response from GBCI? Thanks!

No, but here is my opinion based on my research and experience. We did not discuss exposed structure as unique circumstance when I was working on credit development. The CARB referenced standard is specific to particleboard and MDF, so you can't use that for exposed structure. So you must use the general emissions standard for walls, ceilings, floors as appropriate to the installed location. That said, if you can meet the CARB composite wood ULEF targets or no added formaldehyde for engineered wood, then I would make an argument under special circumstances that you meet the intent of the credit.

I pulled out my copy to see if there is a reason you could not apply the Standard Method to structural wood. From the Scope section: "1.1.1 This method applies to any product category generally used within the envelope of an enclosed indoor environment. The method is applicable to products that can be tested whole or by representative sample in environmental chambers." It goes on to list interior products as examples, but does not preclude others. The collection, packaging and shipping sections could all apply to a structural wood product. Perhaps test prep is the question. It does say "For products not covered in this specification, it may be necessary to develop alternate procedures for preparation of test specimens. If procedures other than described in this section are used, they shall be fully described and reported." It doesn't appear that many adjustments would be required. I don't see why you couldn't choose between a product with a finish or preassembled, or come up with a reasonable loading factor. It looks like you must suspend the sample in the chamber since is has exposure on multiple sides. Once you make those decisions, the actual testing, sampling, and analysis shouldn't be problematic. My conclusion is that you should be able to apply the Standard Method to exposed structural wood. Caveat: I don't have personal experience with testing.

The interpretation addresses only American market. What approach concerning OSB should be used in Europe?

Please take a look at page 4 of the "LEED v4 EQ Low Emitting Third Party Certifications and Labels" table of acceptable certifications and programs. There you will see acceptance of Blue Angel RAL UZ 76, BVB, French VOC classes A and A+, and Finnish M1 for composite wood evaluation.   This is based on this wording in the credit itself: "For projects outside the U.S., composite wood must be documented not to exceed a concentration limit of 0.05 ppm of formaldehyde (0.06 mg/m²-h when expressed as emission rate) as tested following either EN-717-1:2004, following ISO 16000-3: 2010, ISO 16000-6: 2011, ISO 16000-9: 2006, ISO 16000-11:2006, or following CEN/TS 16516: 2013 either in conjunction with AgBB or with Belgian or French legislation on VOC emission class labeling."   I should expect that this could allow you to deliver the relevant documentation if you like.

These products as well as the quote from the manual is relevant for Composite Wood Evaluation. While the OSB in my case should be evaluated with General emissions evaluation. Theoretically there is statement for projects outside US, but I could not find compliant products. All OSB products follow the the methodology as defined in Composite Wood Evaluation...

Why do your products need the general emissions evaluation, while the LEED Interpretation with the ID#10466, https://www.usgbc.org/leedaddenda/10466, states that structural wood products (including structural plywood, oriented strand board, ...) are not required to meet the general emissions evaluation? The suppliers of the OSB should be able to demonstrate compliance with the additional criteria set out in that LEED Interpretation.

As I wrote in my first post, the mentioned interpretation addresses only American market. Replacing testing according to CDPH v1.1 Standard Method... which is an American standard not in use in Europe with, in case of OSB, Voluntary Product Standard – Performance Standard for Wood‐Based Structural‐Use Panels (PS 2‐10) which is another American standard not in use in Europe. The interpretation does not address the German AgBB Testing and Evaluation Scheme or any other standard applicable for General Emissions evaluations in Europe. 

Yes and No. The basic statement is that engineered wood does not need CDPH or AgBB testing, meaning it will need only formaldehyde evaluation as for composite wood, as long as their is not any additional VOC containing finish on the surface. And the credit says that, if only formaldehyde is of interest, then you perform the evaluation either with American standards, or with European standards as described there. I should be surprised if none of the large OSB suppliers were able to deliver any such documentation, as they have to deal with formaldehyde for several markets in Europe as well.