Low Emitting Interiors - Move HC only criteria to all BD&C

I am not happy with the VOC content regulations for exterior applied products being in this credit here (Health Care only).

Low-Emitting Interiors credit deals with long-term exposure indoors, not with protection of outdoor air.

This could rather become part of Materials and Resources credit. And - the test method needs to be updated - the present test method works fine only for solvent-based products, it fails technically with many modern low-emitting products. ISO 11890 is the state-of-the-art testing standard.

I agree with Tom on expanding the exterior applied wet applied product requirements from Healthcare to all BD&C projects. However, we also need to figure out how to deal with the inevitable oddball product where CARB 2007 SCM or Rule 1168 compliant products are not available. An all or nothing approach doesn’t quite make sense where every single product is counted. As an example, I don’t think the entire project should be penalized for using a graphic arts coating for minimal exterior painting. If the credit is unworkable, project teams won’t use it and we miss an opportunity to positively impact the environmental footprint for the project as a whole.

Reinhard, I appreciate your point regarding where exterior coatings, sealants and adhesives belong in LEED 2012. However, I believe there are enough applications on building exteriors near operative HVAC systems to merit using lower VOC products on the exterior. In general construction sequencing, the exterior finishes are among the last products to be installed on a building as site work must be complete and the job dirt removed prior to application on large panels. Use of the CARB 2007 SCM and Rule 1168 are a positive means to accomplish this.

This brings me to what I believe is a hole in the system. The BD&C interior requirements cover materials applied to the building interior defined as “everything within the waterproofing envelope”. The exterior Healthcare requirements cover materials applied to the building exterior defined as “everything outside the waterproofing membrane”.

So, where do the waterproofing materials fit?

We used to live in a world where buildings were built with no secondary drainage plane waterproofing materials or, at best, where a non woven sheet material was stapled in place. Due to many failed building envelopes involving materials degradation and water intrusion, the general design principles for building envelopes have changed. Sheet stock is rapidly being replaced with full surface adhesive rubberized asphalt sheets, spray applied polyurethane foam, and spray and roller applied bituminous, acrylic, epoxy and urethane coatings. Widespread use of these products has progressed so quickly that the regulatory system hasn’t entirely caught up. Some manufacturers classify products applied to gross square footage as sealants even though they would meet the definition of coatings.

For most of these products, the initial application causes few emissions or IEQ problems. They are applied in open field conditions to exterior walls not generally in proximity to operative HVAC systems. In construction sequencing, application is relatively early as the objective is to cover cavity and backer surfaces such as Densglass, concrete masonry units and plywood to prevent moisture intrusion and related microbial and fungal activity.

However, once the exterior sheathing and veneers are applied, the secondary drainage plane waterproofing and air barrier materials are closed in the wall cavity. Some of these products, high build materials in particular; evolve VOCs and other materials slowly over time.

Including waterproofing materials, including adhesive applied and self adhesive sheet goods, and treating them with the same rigor as other exterior applied materials opens a new suite of complicated issues. You are probably aware of the stakeholder conversations regarding SPF systems. That probably has to work through stakeholder discussions and will be covered outside the scope of coatings and sealants. However, I believe we can make a good start where it makes sense within the CARB 2007 SCM and Rule 1168 regulatory frameworks.

Reinhard, with regards to your comments regarding VOC content testing, where necessary for third party certification purposes I believe it appropriate to allow multiple options including USEPA’s Method 24 and ASTM D6886. I don’t know anything about the ISO standard you referenced, but would like to hear more about it. At least in the US regulatory system, because of the legal aspects I still believe we have to allow the regulatory default of calculation of VOC content.

Tom, you have a valid point regarding exempt VOCs. However, I think we need to be careful about overstating the problem with regards to exterior applications. Yes, acetone is exempt. Yes, it flashes rapidly. No, it isn’t particularly toxic except as an initial CNS depressant. A coatings manufacturer would not use an exempt solvent unless it was necessary for performance of the product. Every raw material input is more expensive than water. As green building advocates, we can help educate architects and owners about product attributes so they can weigh the benefits and choose the materials that will be help the building live to a ripe old age.

We can’t forget that coatings and sealants are meant to protect substrates from degradation and assure materials meet their life cycle objectives. Take a walk around D.C. and look at all of the weather damaged Indiana limestone and marble. If you could walk up to the Washington Monument, you would see large areas where the stone simply dissolved and was replaced with epoxy patching material. The National Cathedral uses no exterior coatings or treatments and is instead blessed with a full time masonry carving and restoration crew. The rest of the building inventory can’t be left to chance.

I’m not saying that all exempts are created equal and advocate for disallowing the use of methylene chloride and perchloroethylene as exempt solvents in all circumstances.