NON-TOXIC CONSTRUCTION GUIDELINES
by Richard Conrad, Ph.D. updated January 23, 2010
When remodeling or building to provide a structure that is non-toxic for the general population and safe for persons with chemical sensitivities, unforseen situations and problems will arise, and everything that is allowed to go wrong will probably go wrong. Foresight, detailed specifications and careful on-site supervision are key. New concepts and methods are necessary for success.
Use only products and procedures that have been specifically tested and approved by a designated client's advocate. This advocate should be acceptable to the client, the architect and the contractor. The advocate should be a particular person or persons who together have an intimate understanding of chemical sensitivities, have non-toxic construction experience, and a "good nose." The agent's participation and oversight in all stages of planning and construction is essential. The architect and contractor should agree that the agent's approval in writing must be obtained for each procedure, component, material, brand name and in some cases each batch before its use.
Use only one new material at a time, with agent testing at each step; don't mix unknowns. Scale up gradually, initially doing only one room. Obtain the advocate's approval before covering up one coat or construction layer with another. Momentum and the push to "just get the job done" can can ruin a whole project if they take precedence over consistent adherence to specifications and to the testing and approval procedure. A break in the chain of communication from agent to contractor to workman can have disastrous results; that is why constant supervision is necessary. Contractors should agree to never exercise their own preferences, but should always check with the advocate. Testing and toxicity control is essential.
NO CHANGES (Always Ask First)
NO NEW DECISIONS (Present Options to Advocate)
STICK TO THE PROTOCOL
TAKE NOTHING FOR GRANTED: products and their components change from original test sample to batch, batch to batch, and sometimes within batches, box to box, bag to bag.
JUST BECAUSE A PRODUCT IS FOUND ON SITE DOESN'T MEAN THAT IT IS APPROVED OR SAFE.
NO WOOD PRESERVATIVES
NO PESTICIDES OR HERBICIDES
ALLOWED ON OR NEAR THE SITE.
NO DUMPING OF ANYTHING ON OR NEAR THE SITE.
Ask agent about procedures for disposing of liquids and slurries.
These guidelines cover ALL PRODUCTS, COMPONENTS, MATERIALS, CHEMICALS, and CLEANING MATERIALS, including:
Paints, paint thinners, solvents
Epoxies, glues, and pipe dope
Concrete additives, thin-set and grout additives
Caulks, spackles, sheet rock joint compounds (use nothing containing vinyl or mercury compounds: joint compound in tubs usually has both vinyl acrylics and mercury preservative)
Oils and penetrating oils
Fuels, hydraulic fluids, and lubricants (no 2-cycle engines allowed)
PLAN AHEAD AND GET SPECIFIC APPROVAL FOR ALL COMBUSTION AND COMBUSTION ENGINE USE ON SITE.
KEEP ALL DOORS AND WINDOWS CLOSED AND ALL OPENINGS SEALED OFF WITH A TEMPORARY VAPOR BARRIER WHEN VEHICLE OR ENGINE EXHAUST IS OUTSIDE.
IF A SHOP VACUUM is to be used near or inside a finished or almost finished room, PUT THE VACUUM ITSELF OUTSIDE, WITH WINDOW NEARLY CLOSED ON LONG HOSE, and with all nearby doors and windows closed.
MIX ALL DRY OR DUSTY MATERIALS SUCH AS CONCRETE, PLASTER, JOINT COMPOUND, FIXALL, THIN-SET, GROUT, ETC. OUTSIDE, WITH ALL WINDOWS AND DOORS CLOSED.
DO ALL TILE-CUTTING, AND WHEN POSSIBLE, WOOD SAWING AND SANDING, OUTSIDE OF THE HOUSE, WITH WINDOWS AND DOORS CLOSED. "WET sand" sheetrock mud with sponge.
SOME SAFE PRODUCTS (some of these are safe only after cured or evaporated) :
Teflon pipe-thread tape
Mineral oil (as lubricant)
Degreasers: isopropanol (99% works best), vinegar
Old-fashioned non-plasticized "Fix-all"
"Murco" sheet rock joint compound (can also use for spackle)
100% Silicone caulk (some types only, especially those with FDA approval for contact with food once cured)
Closed-cell foam polyethyene flexible caulking rod ("caulk backing/pre-caulking" material)
Only some polyethylene-type tarps, others contain toxic plasticizers or toxins from recycled materials.
Wood should be mildew-free, and kiln dried where possible.
Generally, the most well-tolerated woods are ash and maple.
Avoid all wood that contains preservatives, with the exception of borate type compounds, which are OK (except avoid breathing the dust when sawing or sanding).
When applying paints and sealers, the time between coats should be greatly increased (4- or 5-fold) over the manufacturer's recommendations. It is best to use thin coats, with more coats if necessary to cover, rather than a thick coat to try to cover in one coat.
Degrease all metal ducts, inside and outside, before installation. (Corrugated metal ducts should not be used because they have grease inside and cannot be degreased).
For ceramic tile: Some gray thin-sets contain kerosene, plus unacceptably toxic additives. Almost all white thin-sets still contain the unacceptably toxic additives (obtain detailed tiling advice from R. Conrad). Some thermo-floor additives, and concrete additives such as retarders (hot weather mix) are unacceptably toxic. Many tile and grout sealers (not all) are toxic.
Use "Tyvek" or "Air Stop" moisture barrier instead of black paper. Caution: check to be sure that the Tyvek was not manufactured from recycled plastics (it might then contain toxins), and that it did not pick up toxic odors during warehouse storage or transit. Consult R. Conrad for safe insulation and vapor barrier procedures.
Where painted metal (cabinets, doors, door frames, etc.) are to be used, use only powder-coated baked paint finishes. Some types of powder coat are OK, and others are not. Test first.
New baseboard or central heating units should be "burned-in" off-site to prevent contaminating new rooms with their off-gassed vapors.
If a bake-out is used to reduce offgassing of new materials, the procedure must be planned and carried out with care to prevent creating new problems. Consult with R. Conrad.
Use no particle board at all. Minimize use of plywood, use only external type, and seal it from living spaces with a vapor barrier. “Baltic” or “Russian” birch plywood is non-toxic. So is Columbia Forest Products plywood which uses soy-based glue.
"Hardi-board" composition concrete board is a useful and relatively safe material that can be used in place of plywood, and it does not require painting. It can be used in place of other concrete boards for tiling over.
Most new wall-to-wall type carpets are exceedingly toxic. Carpet pads and carpet glues are also. Consult R. Conrad for safe alternatives.
The results of testing small samples is only preliminary and cannot be relied on alone, because what may appear to be safe in a few square feet section may not be tolerable when scaled up to hundreds of square feet. R. Conrad can supply intermediate-scale testing methods. The age, process of manufacture, and ingredient composition of the sample must be the same as the actual product to be used. (A sample that has been outgassing for a year will not be a good indicator.)
The above toxic product and safe product lists are incomplete. Remember that "recycled" does not mean less toxic: recycled materials can be more toxic. The source and ingredients of concrete, blocks, and bricks should be researched. The kilns are sometimes fueled with toxic materials (such as rubber tires or other toxic waste).
Contact R. Conrad for specific questions, and for design of safe heating and other systems.