Framing

Introduction: Here in the Pacific northwest, Douglas fir is commonly used for wooden framing members. But Douglas fir is very aromatic (like other softwoods) and intolerable to many people with sensitivities. Fortunately, because the studs are contained within the wall cavities, this usually isn't a problem, unless a non-tight interior wall paneling is used, such as T&G boards. If drywall, MgO board, or another relatively solid barrier is used for the interior walls, most odors and substances in the wall cavity will not migrate into the living space, unless at a very slow rate. In general, the most important materials in terms of indoor air quality are the materials closest to you: the wall paneling and wall paint; the finish floor and seal; the trim and furniture; appliances, etc.

Douglas fir is a softwood and softwoods are generally more odorous than hardwoods. See The Healthy House article to learn more about the difference between softwood and hardwood.

Mitigating Outgassing: If it is necessary for you to mitigate the outgassing of the Douglas fir wood inside the walls, try covering it with one or two coats of a safe paint. In particular, I have found pure acrylic to be useful in blocking odors. Painting the wood will help block the aromatic qualities and slow the wood's out-gassing to, hopefully, a tolerable level. That, in conjunction with using a solid interior wall substrate should be enough to seal out the douglas fir. Another option includes using a less aromatic wood for the framing, such as redwood, for example.

One product to consider is Timbersil, which is a combination of wood and amorphous glass. This process hardens the wood and makes it resistant to rot and termites. It also reduces the aromatic qualities of the wood significantly.

Sealing/Protecting for Moisture: For moisture protection, you can seal your framing with a water-based silicone seal. The wood will breathe and it will repel moisture at the same time. Two products to consider are Earthpaint's Never Peel and Miracle Cover.

Sealing/Protecting for Insects and Termites: George Swanson, author of "Breathing Walls," recommends sealing the wood framing with a mix of magnesium phosphate (30%) with bentonite or kaolin clay (68%) and borax (2%). Alternatively, and easier, would be to use a safe, breathable paint to coat the framing.

I like to add diatomaceous earth at the bottom of the wall cavities to kill any insects that might cross its path.

Steel framing members are a good option for those too sensitive for wood framing, but may not be ideal for those with EMF sensitivities. Oil is used in the machines that cut metal and there may be residue left over on the studs. Each stud may need to be washed with soap and water. After framing is complete, but before the walls are enclosed, consider grounding the steel framing.