As I mentioned in my previous post, we recently bought a house. We painted the interior, top to bottom and I wanted to include some natural paints in the mix. You might be wondering, what a natural paint is. In a nutshell it can be defined as petroleum free containing plant and mineral-based ingredients. These paints are also breathable and are an excellent choice for walls that are built for thermal mass applications, such as Durisol built or rammed earth walls. I tracked down a Montreal-based store called Tockay, which happens to sell two natural paint brands out of Germany, Auro and Kreidezeit. I worked with Carole Hili at Tockay, who helped me choose the right kind of paint for each room. She suggested Auro’s lime-based paint for the basement because the paint will absorb excess moisture in the air — perfect for the summer! Let me tell you, so far it works. It’s difficult to say for certain because we have no idea what the basement was like before we moved in, but there isn’t a drop of dampness and we’ve had no need for the dehumidifier.
Why use a natural paint? With all the hype by the paint giants about low and zero VOC (volatile organic compounds) paints, the focus of attention has drifted away from the fact that the main ingredient in these paints is petroleum (in the form of acrylic, or if oil-based, alkyd). Further, the standard gallon of paint contains plenty of synthetic compounds which are used to improve the drying, spreading and binding properties, as well as synthetic pigments. If you want to get away from using petroleum-based paints, paints made from plant and mineral based ingredients are the way to go.
- Stunning, rich colour and wall texture (flat finish, looks a bit like velvet).
- Zero off-gassing of volatile organic compounds.
- Mould and mildew resistant.
- Breatheable, so good for thermal mass applications.
- Great for moderating moisture-prone areas such as basements.
- Responsible disposal. Let leftover paint dry and put it in your compost bin (note: not sure it would be accepted in city compost programs, so I’d stick to your backyard composter.). Clean paint containers are recyclable. Or let it dry and put it in the garbage. The website tells you not to pour it down the sewer or sink. It can also be stored in its original container (edges of the container wiped clean) for up to two years without it drying out.
Type of paint: There are several lines of Auro products available, we used the lime paint which can be applied with an ordinary (high quality) roller and brush. The website indicates that the lime paint and can be applied to exterior materials such as weather resistant plasters, concrete, limestone or standstone. Applicable interior surfaces are clay, drywall, woodchip wallpaper or mineral paint walls in good shape. It is not suitable for plastic surfaces, wood, or any high gloss surfaces as it won’t adhere well. Always do a test sample before applying. All surfaces need a certain amount of preparation depending on what they are. Consult the Auro website for more specific information for using lime-based paints.
Priming: There are times when you don’t want a breatheable wall surface. For instance, if there are layers and layers of paint from years past, it’s probably a good idea to seal those up so their fumes don’t continue to off-gas. Priming a surface before applying this paint will seal the surface to which it is applied and provide a “stickiness” that the paint needs to adhere to. We decided to use Benjamin Moore EcoSpec primer (yes, petroleum-based — I am nothing, if not a bunch of contraditions!), but tested it first to make sure the lime paint would adhere to the surface — which it did.
Mixing: One of the advantages of Auro lime paint vs. a clay paint, is that it comes in liquid form, so it’s easier to mix. However, here is a stumbling block that may prevent those but the most adventurous, from trying the paint: You have to mix in the colour yourself — assuming you want a paint with colour. Also, you should mix enough for one full coat at a time so there aren’t any visible changes in colour. We went with a shade that was an intense yellow which looks great in the rec. room, but I decided to tone it down to a paler yellow for the hallway and stairwell. Mixing the paint yourself also gives you a certain amount of control to change the colour if you want. So, you have to be a bit brave and convince yourself that if you can cook, you can paint (or at least I did), since measuring accurately is important if you’re going after specific shades. Getting the quantities right involves calculating how much paint you need in total, the coverage of the paint and the amount of pigment you need to make your desired colour. In our case, we calculated that we would paint two coats (in addition to the primer) on the stairwell, hallway and rec room, which was about 500 square feet in surface area, so 1000 square feet in total (two coats). The paint coverage is about one litre per ten square feet (notice I’m mixing metric and Imperial, like the good Canadian that I am). We bought the ten litre bucket of white paint and one half litre bottle of pigment for the entire job. Add colour pigment to get the desired shade you want. Stir well for a good, solid ten minutes to make sure the colour is evenly saturated. Carole recommended using a radiator brush which has long bristles and will capture all the paint and blend it well. Once the colour is mixed, the website recommends diluting the paint with water by 20% — so for example, to one litre of paint, add 200 ml of water to get 1.2 litres. Note that porous surfaces will absorb more paint than less porous, therefore, you might have to play with the water content a bit. If the surface is really absorbent, you might want to try diluting it another 10% or so. On a primed wall with an acrylic primer, the primer stops the paint from being absorbed.
Application: The paint is applied in the same way as an acrylic-based paint. Cut the edges first with a good brush (ie., outline the edges of the walls using a brush). Then apply paint with a roller by applying in a “W” shape and spreading it out from there. Let the paint dry for 24 hours before applying a second coat. We noticed that once the paint had dried, there was a distinct line between the “cut” area and the rolled area, however, after a few days — perhaps as long as a week — the difference disappeared. As for smell, there was a little bit of a damp smell as it was being applied, but once it dried, we couldn’t even tell it had been painted.
Cost: The cost of the paint is about the same as that of a high-end water-based acrylic paint, plus the cost of the pigment. So, the darker the colour you choose, the more expensive the job will be. A ten litre bucket of paint cost $150. The bottle of pigment was $40 for a half litre. The look and feel of the paint is fantastic. It has a lovely texture and a rich depth of colour, without these positive attributes I wouldn’t be impressed with the paint regardless of its greeness. Further, the application is similar to acrylic-based paints so it is not difficult to use. But I think what I like the best is what you don’t see:
- Auro is a certified carbon neutral company by an independent third party;
- It uses renewable and plentiful ingredients for its products;
- There is a complete lack of off-gassing of anything harmful;
- The ease of safe disposal of the product at end of use.
For more information on the complete line of Auro products available in Canada, visit Tockay’s website.
(Please note: the information in this post should be taken as a guideline only, as it is based on my experience. For proper guidance, it is important to consult directly with a vendor or distributor of Auro paint. Always read all the information provided by the company and test a small area before using).
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