Choosing the Right Finishes

The choice of healthy construction materials became a major issue in the mid-twentieth century, as builders began using toxic, artificial products, while also sealing buildings as tightly as they could.

Sealed buildings conserve energy, of course. However, they also trap harmful gases. When toxic materials are used in construction, indoor air quality can actually reach urban pollution levels.

The culprit is VOCs, or volatile organic compounds. Products high in VOCs continue off-gassing long after they’re installed, damaging your long-term health and bearing a daily impact on your your mental clarity, productivity and mood.

So, it’s important to select a healthy product – especially since finishes are found just about everywhere in your home, from floors to cabinets to light fixtures.

How to choose the right finish? LEED can help.

LEED (the Leadership in Energy and Environmental Design) is a nationally accepted, third-party rating system which awards points for outstanding green performance in six categories, including Indoor Environmental Air Quality, Materials & Resources, and Energy & Atmosphere.

With enough points, a home can be LEED-certified at the Silver, Gold or Platinum level. For example, see Clarum’s gold-certified Hansen Lane community in Danville, CA; or our platinum-certified townhome project in Palo Alto, Cambridge Plaza. 

To accrue points, interior finishes must not exceed certain VOC limits. Here’s a list of some common finishes, with LEED requirements noted. (However, requirements may change. For the most updated figures, please visit the USGBC website).

• Varnishes. Usually made of resin and drying oil, varnishes are heated until they polymerize: a chemical reaction that results in a clear finish. VOC limit: 350 g/L.

• Shellacs. In its natural form, shellac is a resin secreted by the lac bug of India and Thailand, which cures to a fantastic shine by evaporation. VOC limit: 730 g/L clear, 550 g/L pigmented.

• Lacquers. Fast-drying and durable, lacquer also cures by evaporation. The binder is made of cellulose from wood or cotton; the thinner is often high in solvents. VOC limit: 550 g/L.

• Natural oils. Linseed oil from flax seeds is boiled and mixed with chemicals. Tung oil comes from Asian tree nuts. Slow-drying and durable, these natural oils cure by absorbing oxygen. Naturally low in VOCs.

• Water-based finishes. Based in solvents but thinned by water, these finishes cure by interlocking particles as the water evaporates. Moderately durable. Generally low-VOC.

• Wood stains. These formulas contain a pigment to add color without obscuring the grain. Unlike paint, they penetrate deeply, actually becoming part of the wood. VOC limit: 250 g/L.

VOC limits for other finishes include flat paints/primers, 50 g/L; non-flat paints/primers, 150 g/L; floor coatings, 100 g/L; waterproofing sealants, 250 g/L; sanding sealants, 275 g/L; and other sealants, 200 g/L.

At Clarum, we’re very proud of our LEED-certified homes. For a home that adds to your health every day with clean, safe air to breathe, consider us your building experts.

Talk to us about building your new green home. Call Clarum at 650.322.7069.