Lumber and sheathing questions
Carfar96
| Posted in Green Products and Materials on
We are building a new home and one of children has chemical sensitivities. I am becoming overwhelmed with the choices for everything. I want an energy efficient home, but I am most concerned about building a nontoxic house.. The foundation (walkout basement) is poured and we are onto framing. Any suggestions for more nontoxic lumber products and wall sheathing? Thank you!
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Carolyn: as a general proposition, the less processing building materials undergo, the better for anyone with concerns about chemicals. So boards for sheathing may be preferable to plywood or OSB, which contain glues. Framing lumber may be preferable to I-joists. But exposure to framing or sheathing is probably minor.
I'd be a lot more concerned about finish materials, like paint. Go with no VOC, as opposed to low VOC.
Obviously, no carpeting. Real wood floors, as opposed to engineered wood.
What sort of insulation is contemplated?
I'd certainly plan on a good ventilation system.
In general, the more a material looks like what it came from, the better. The fewer plastics, the better. The fewer glues, the better. The less complication, the better. Complicated means lots of materials which means engineered, chemically-processed stuff and contractors who can assemble or detail them wrong, leading to conditions that cause health hazards. Keep it simple and keep it natural. Simple and natural also tend to be inherently more durable, as a bonus. If I had this limitation I would not build a wood-framed structure at all. Too complicated, too many different materials, too many opportunities for something chemically problematic to sneak by. I would build with thick AAC blocks and unpainted gypsum or lime plaster on the inside. Sounds like it's too late for that, so just do the best you can and install a best-in-class ventilation system, as Stephen has suggested.
Carolyn,
Q. "Lumber and sheathing questions: ... Any suggestions for more nontoxic lumber products and wall sheathing?"
A. When it comes to lumber -- spruce or fir 2x4s, 2x6s, 2x8s, etc. -- I have never heard of anyone referring to these materials as "toxic." However, if you have any reason to believe that lumber might be toxic to your children, you might want to build your walls out of concrete blocks (CMUs) to avoid the use of lumber.
If you are worried that plywood or OSB might be toxic to your children, then you can choose to sheathe your house with diagonal boards. Again, spruce or fir are typical species, and I have never heard of anyone referring to these species as toxic.
It's important to note, however, that a well-built house has one or more air barriers. If you use gypsum drywall as your interior finish material -- this is the way that most homes in the U.S. are finished on the interior -- and if you install the drywall in an airtight manner, then your wall sheathing will be on the exterior side of your air barrier. It's hard to imagine that your wall sheathing will affect your children.
"Real wood floors, as opposed to engineered wood."
Previous commenters are correct that interior finishes are more critical for your concerns than framing/sheathing, but you actually you might be better off with engineered wood. 'Real wood' floors need to be finished in place, and unless you can find a no-VOC finish the outgassing will be problematic. Water-based is better than oil-based but you are still liable to find sensitivity issues. Engineered wood is factory finished and fully UV cured before shipment and any residual solvents in the substrate will be sealed in by the finish. Lifetime finish warranties are common for residential installations of these products, which means you are not likely to encounter outgassing from repairs during the length of your occupancy.
James,
They do sell pre-finished tongue-and-groove solid wood flooring now; no need to have it finished in place after installation.
Hey Nate - you're quite right. I'll admit to a slight prejudice against the solid wood pre finished on account of the tendency to a wider v groove than the engineered product.
Carolyn,
You are getting a lot of great advice. I am in the process of building a house right now as well, and trying to avoid as much toxicity as possible. We are going with solid wood floors with a zero-VOC finish - in our case, that is Rubio Monocoat, but Eukula is a good product, as well. In the basement, we are leaving the slab exposed - I figure the fewer materials you use, the less chance there will be something toxic. There are sealers and stains available from AFM Safecoat that are very low to no VOC.
I agree with Martin for the sheathing - since it will be outside of your air barrier most likely, it should not be a major issue. Definitely go for plywood over OSB, though, in my opinion. In my case, we are building with Durisol blocks which are a mineralized wood ICF form, but as others noted, it sounds like you are too far along to change tack to something other than a wood frame building.
As a general rule, go with solid wood wherever possible, avoid treated lumber, and definitely do not use any MDF or fiberboard. Especially so within your air-envelope.
CertainTeed also makes a drywall that absorbs VOCs - AirRenew - that can play an important role in capturing anything that makes it through your screening.
As a final piece of advice - if you have the time and opportunity, you could expose your child to a small sample of any materials you plan to use within the house. If they have a reaction, you know you don't want it in your home.
Good luck!!
Oh yeah, and be prepared to pay a premium for everything that goes counter to standard products and practices, unless you have a great contractor.
Sorry for the delay! Thank you everyone for you responses! I am so overwhelmed by the advice and help you have provided. This is my first time posting on this forum and I am so impressed by all of you!!! You are all lifesavers. I am fairly certain we will be going with plywood wall sheathing. Thank you for all of the advice on the interior choices as well. Those decisions are not far behind, so that is very helpful. We are doing a geothermal system and blown cellulose insulation. Any suggestions on windows? I want to avoid vinyl so we have been getting quotes on Fiberglass windows. Wood doors seem to be out of our budget for both exterior and interior doors. Any less toxic suggestions there? Thank you!
Carolyn,
I have never heard of a toxic reaction from a door. If you have chosen to buy fiberglass windows, you may also want to install a fiberglass door.
If you prefer steel, lots of manufacturers sell steel exterior doors. If your children tolerate riding in a car, that means that they use painted steel doors every time they get into a car.
Given that polyurethane foam is a potential source of chemical reactions, if you want to play it super safe, you might opt for a polystyrene foam core door. Among major brands, Jeld Wen is the only one I know of that uses polystyrene. Available in fiberglass or steel.
For interior doors, there are molded doors that are basically wood fibers glued together, hollow doors that are thin plywood over a wood frame with a cardboard honeycomb inside, or solid wood doors. Jeld Wen uses low emissions glues in their molded doors, but perhaps the flush hollow style would be safer if you want to minimize the use of glue.
If you want to save money, consider used doors. Any emsissions from glues in them would be long gone, and you might save money. (Might, because the installation cost could go up if they need finessing, and could easily swamp your savings on materials).
The word "toxic" is often bandied about casually. I'll say this about used doors, however: If they have lead paint, used doors may actually be toxic -- not just "toxic."