Let's revisit some of the natural and effective finishes we have used for centuries before the days of chemical finishes.
1. Wood Finishes
Natural Oils and Waxes
|milk paint pigments & hemp on floors,|
hemp on window frame,
still unsealed cabinets
Linseed, Tung, Hemp and Walnut Oil are drying oils (although some claim Walnut is a semi-drying oil); they all penetrate, harden and preserve wood, and provide a long-lasting finish that does not turn rancid.
I used Hemp Oil on all the interior wood in my chemical-free tiny home. I am really happy with it. But the ladder to the loft does get very grimy (i.e. the dirt from feet mixes with the oil). Not sure if all the oils would do the same, but I think so.
Wood can then be finished with a beeswax polish for extra durability. I don't know how long it takes to dry but I found that it was sticky for a while and attracted dust and grime on surfaces that are walked on. I used beeswax on the window sills to provide a water-resistant finish and I'm really happy with it. This Beeswax/Carnauba Polish would be great, or you can make your own, but use one of the drying oils listed above. I wouldn't recommend using olive or other (non-drying) oils that can go rancid on wood. Here's a how-to on finishing wood with natural oil and wax.
|Photo from homesteadhouse.ca|
Non-toxic milk paint pigments can be used as a stain applied to the raw wood before finishing with oil and wax. Here is my how-to for these pigments as they are very tricky to work with! I used them on my floors, my bathroom cabinets and my two stairs.
I have used ECOS sealer on the wood in the kitchen as it is a little more durable than hemp in the kitchen. I also wanted something that did not darken the wood as much as hemp. I can't recommend this clear varnish enough (though the shipping was very expensive to Canada). It is truly zero VOC from my own assessment, and to me is benign. A happy surprise after testing so many "0 VOC" paints and tile sealers that took me out.
AMF wood sealers are also reported to be good. AMF Lock in New Wood Sealer finished with AMF Hardseal or Polyureseal.
2. VOC-Free Paint?
Apart from that, there are a myriad of paints claiming to be green or zero VOC. It's not easy to find out exactly what is in them, and some ingredients like biocides might not be listed. For example, conventional manufacturer - Benjamin Moore makes a "zero-VOC" paint that is high-quality, and comes in great colours, but it was intolerable for me while wet.
Here are some alternatives:
Mythic Paint - The green building supply store in Vancouver claims that Mythic is the best of the non-toxic acrylics. When dry it seemed totally fine but I'm still not certain of its safety for MCSers when wet. If you are in the US it's easy to order it online from their website and in Canada you have to get it at specialty paint or green building supply stores. It's definitely the best out of latex paints. I used mythic in my washroom.
YOLO Colorhouse - Once you get past the name (sigh), this paint comes in a pretty good range of colours and they can custom match a colour for you. What exactly is in it no one can tell you. I have heard of EIs who can tolerate it but I think Mythic is better. It's available in stores across Canada and the US and online @ YOLO Colorhouse.
AFM Safecoat Zero VOC Paint- Contains no formaldehyde, ammonia, crystalline silica, or ethylene glycol. Tintable to thousands of colors with zero VOC colorants. Recommended by many EIs as well.
Green Planet Paints - (Natural Source, Clay-Based Paint) available online, and in specialty paint stores in Canada and the US.
Auro Natural Paints - (Natural Source, Clay-Based Paint) available online, ships to US and Canada.
If you are using magnesium oxide board you will need to prime before painting AFM Safecoat Low VOC Transitional Primer or Mythic primer, which is OK for me, but not great when wet.
Plaster is applied directly to earthen walls or pumice-crete.
There are clay-based plasters and lime-based plasters. I prefer lime because it is naturally mould resistant. Plasters can be tinted with natural pigments. Here is a detailed post on my experiences using clay plaster and limewash in my tiny house.
To learn more, get yourself a copy of The Natural Plaster Book.
4. Earthen Floor Finishes
If you don't have ox blood on hand, no problem, you can seal your earthen floor with any of the hardening oils we talked about under wood finishes (above). I would use Hemp Oil. This blogger claims that Walnut Oil went rancid with time. Beeswax can also be used in the final coat for extra protection if desired.
Sealing Toxic or Exterior Wood
To protect exterior wood against the elements you could use something a little stronger (as the VOCs will not be within the building envelope) like: AFM Naturals Clear Penetrating Oil, or Sinan Company N. 253 Natural Undercoat Enamel (if you can find that in-store). I left my exterior cedar unsealed. There is another method to naturally seal cedar which is burning it, if interested you should look into that.
Sealing Tile, Concrete, Stone
For sealing grout use AFM Safecoat Grout Sealer or AFM Safecoat Safe Seal.
I used Murco as a joint compound and found it totally tolerable. It has cracked at the joints which is something other builders have noted as well.
Paula Baker-Laport's: Prescriptions for a Healthy Home has been indispensable in informing this post. Get it here (Canada), or here (USA).
1 biocides, ammonia, crystalline silica, ethylene glycol, phthalates, isocyanate, mineral spirits, benzene, propane sulfone, petroleum distillates, nitrobenzene, ammonia, naphtha, and phenol. Sources: North Carolina Cooperative ExtensionService, Grassroots Info, & Cleveland Clinic .