Let's revisit some of the natural and effective finishes we have used for centuries as well as some of the new zero-VOC options.
1. Wood Finishes
Natural Oils and Waxes
|Milk paint pigments & hemp on floors,|
hemp on window frame,
still unsealed cabinets
Linseed, tung, refined hemp and walnut oil are drying oils (although some claim Walnut is a semi-drying oil so I would not recommend it over the others - I have seen it turn floors rancid). They all penetrate, harden and preserve wood and provide a long-lasting finish that does not turn rancid. Coconut oil if refined is another option. Just don't use regular cooking coconut oil. I wouldn't recommend using olive or other (non-drying) oils that can go rancid on wood.
Another oil to check out is Penofin Verde which is Brazilian rosewood oil based with "other natural oils combined with select vegetable ester solvents and zero VOC pigments" It has 1g/l VOC.
I used Hemp Oil on all the interior wood in my chemical-free tiny home. I am really happy with it. The ladder to the loft does get grimy, though the dirt does wipe off. Use refined hemp oil (made for floors) as opposed to the edible oil from the grocery store.
Oils need to be reapplied every few years or more in high traffic areas.
Wood can then be finished with a beeswax polish for extra durability. I found that it was sticky for a while until it dried. I used beeswax on the window sills to provide a water-resistant finish and I'm really happy with it. This Beeswax/Carnauba Polish is great. Here's a how-to on finishing wood with natural oil and wax.
Wax needs to be re-applied every year.
|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 was not very happy with these stains.
I would recommend either ECOS Paints stains or AFM Safecoat Stains. Both are water-based.
There are other natural oil-based stains such as Rubio Monocoat and Penofin Verde.
Warning on ECOS varnishes which I previously recommended. There are problems with their varnishes with two people now reporting that water leaves very bad stains on the wood. This is a major problem that would cost a lot of money to fix. I used ECOS sealer on the wood in my kitchen and am very happy with it. I have not had these problems so I do not know what accounts for it, but for now I am suggesting that ECOs should not be used. Though other polyurethane finishes can also have this problem.
AFM wood varnishes are reported to be good. AFM Lock in New Wood Sealer finished with AFM Hardseal or Polyureseal. Polyureseal is highly recommended by The Green Design Center which has a tonne of experience with sensitive customers. These have to be tested against your sensitivities.
2. VOC-Free Paint
There is a myriad of paints claiming to be green or zero-VOC but 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 called Natura that is high-quality, and comes in great colours but contains a mildewcide (something you should avoid). It was intolerable for me while wet. If you want something that is easy to source at a hardware store this is your best bet - just make sure they are using their zero-VOC pigments with it. (Note: other hardware store brands like Behr make a zero-VOC base but do not carry zero-VOC pigments).
Colourhouse and ECOS are other zero-VOC paints that contain a mildewcide.
Here are my top three latex paints:
Mythic Paint - The paints and primers are zero-VOC. This is now only available in the UK. They have sold the formula to a new company so I will update as this unfolds (2016).
AFM Safecoat Zero-VOC Paint - Tintable to thousands of colors. It is zero-VOC with zero-VOC colorants. Recommended by many EIs as well. (Though the primer is low-VOC.) No mildewcides.
ECOs - Their primer and paints are zero-VOC but do contain mildewcides.
Good Natural, Non-Acrylic, Options:
Romabio - The most popular mineral based paints. Clients seem to really like them.
BioShield - Becoming popular in 2016, Bioshield makes chalk and clay paints that people seem to like.
Milk Paint - I used Milk Paint in my chemical-free house to seal in the dust on the walls. On unfinished wood you need to add white glue to milk paint and I have not found a glue that I found 100% tolerable. Milk paint is also not great in a high moisture area like the bathroom because of the casein. (It could be prone to mould in a high moisture area). I would avoid it if I did things again.
Auro Natural Paints - (Natural Source, Clay-Based Paint) available online, ships to US and Canada.
Try AFM Safecoat Low VOC Transitional Primer or their New Wallboard Primer for new drywall (both low-VOC, but they seal in toxins). ECOs is another brand that makes primers including a new wallboard primer (contains mildewcide). Sherwin Williams Promar 200 is a zero-VOC primer (no mildewcide).
AFM makes MetalCoat Primer (zero-VOC), the Mythic Primer above can be used on metal (now out of business). For small applications, you could try non-toxic DecoArt No-Prep Metal Paint.
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
Plywood and MDF should also be sealed with one of the above sealers if you must use it (it gives off formaldehyde).
For sealing in fragrance, smoke, terpenes or other VOCs please contact me for a consultation and we will find the best product for your application.
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. This zero-VOC product Cedar-Seal would be ideal for cedar siding, the same company makes another sealer for other woods.
There are very few exterior paints that are zero-VOC but ECOs and AFM have some options there.
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 but it is not compatible with MgO board. It has cracked at the joints which is something other builders have noted as well. This compound is compatible with MgO.
For regular drywall, drywall mud (spackle) that are zero-VOC are USG SHEETROCK® Brand Lightweight Setting-Type Joint Compounds – EASY SAND 20, EASY SAND 30, EASY SAND 45, EASY SAND 90, EASY SAND 210, EASY SAND 300.
Proform drywall mud is extremely low VOC (considered "zero").
There are so many 0 or extremely low VOC drywall muds available at regular outlets. The powder form is lower in VOCs than the pre-mixed. Even pre-mixed can be found in extremely low-VOC formulations.
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.