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All About Natural Paint

There is no easier or better place to shift away from toxic petrochemicals and move to using natural, non-toxic options than with the paint we put on our walls.

Anybody Can (and Should) Do This
We hear from many people who wish they could build a home with natural materials, but because they live in an existing home they seem to feel there is no way for them to use natural materials. But using natural paints is something that anybody can do, at any time, in any home, and on any wall surface. And the benefits are profound. In terms of your family’s health, it can be better to have a non-natural home painted with natural finishes than to have a natural home painted with toxic petrochemicals. Natural paints are also better for the planet.

Why Not Just Use No-VOC Paint?
By all appearances, the paint industry seems to be getting “greener.” So why not just choose a good no-VOC paint and use that? Turns out, there are quite a few reasons. Firstly, paints labelled as “Low-VOC” or “No-VOC” are far from being non-toxic. Secondly, the petrochemical paint industry has a huge environmental and carbon footprint.

The Dirty Secret About No-VOC Paintdisturbing paint facts
The impetus to reduce the quantities of volatile organic compounds (VOCs) from paints actually had nothing to do with human health concerns. VOC reductions were imposed on the paint industry because they contributed to smog, and only those VOCs that directly contribute to low-level ozone production are covered by these regulations. The US Environmental Protection Agency (EPA), the body that first imposed VOC restrictions, has this to say after testing a range of paints that qualify as low-VOC and finding surprisingly high concentrations of VOCs:

“EPA Reference Method 24 is probably not an adequate method for measuring the VOC content of low-VOC latex paints. …Current bulk analysis and emission test results showed that the VOC contents of low-VOC latex paints are well within the uncertainty range of Method 24, and the method is apparently not precise enough to accurately define the VOC content of those paints.” –Inside IAQ EPA/600/N-98/003

What If It’s Labelled as “Green”
There are some labelling programs that do ensure acrylic (commonly called “latex”) paints are less harmful to occupants. However, the most common labels do not. GreenGuard and Ecologo are the labels most commonly seen in paint stores. They are administered by Underwriters’ Laboratories (UL). Here’s what that standard has to say about its commitment to human health:

“1.14 While this practice lists specific chemicals and associated maximum allowable concentrations, as required by criteria indoor air procedures and specifications, it does not assess the human risk involved with use of the materials either as an installer and/or as an end user.” –UL 2821

green seal logoIf you want to trust a label, find paints certified by GreenSeal GS-11. This is the only standard I can find that actually excludes a wide range of toxic chemicals and has a direct concern for human health.

And Even If It’s Got a Good Green Label…

Despite the fact that they are called “water-based,” all acrylic paints are made from petrochemicals. Coatings consumption worldwide reached 80 billion pounds and $120 billion in value in 2013, according to “Global Paint & Coatings, 2013-2018,” by polymer and chemical market researchers Kusumgar, Nerlfi & Growney. That means that our use of petrochemical paint carries with it the same environmental impacts as any use of crude oil. Don’t like offshore drilling, oil sands, pipelines, greenhouse gas emissions, oil spills, etc? Every time we use acrylic paint, we contribute to all those impacts.

From raw material harvesting through production and end-of-life waste, the 80

From raw material harvesting through production and end-of-life waste, the 80 billion pounds of paints produced annually have a massive impact on the environment.

The embodied energy and embodied carbon emissions of acrylic paint are also very high. Using data from the Inventory of Carbon and Energy V2.0, the paint needed to coat the interior of a typical 2,000 square foot home (primer and two coats of finish) would use about 7,300 megajoules (MJ) of energy to produce, and emit 303 kg of carbon dioxides (or equivalents). That’s the energy in 1.5 barrels of crude oil or 61 gallons of gasoline required to paint every home, and somewhere in the neighbourhood of the same weight in CO2 emissions as the combined weights of the home’s inhabitants!

Now the Good News!
Don’t want to inhale toxic chemicals or contribute to oil spills and climate change? The good news is that there are plenty of accessible, affordable and practical paint options available that are non-toxic and low-impact. Most of the paint manufacturers listed here provide full disclosure of their ingredient lists, meaning that there are no hidden toxins. All have been recommended by people with chemical sensitivities.

Natural paints come in a number of different categories, based on the type of binder they use, and each type of paint has a range of different surfaces it may be used on:

Natural Oil Paints

  • Drying oils (linseed, sunflower, tung, etc) polymerize when exposed to air
  • Some natural oil paints are emulsified with water
  • Indoor & outdoor use
  • Used on almost any substrate

Although many people will have an initial negative reaction to the idea of “oil paints,” these bad associations are from very toxic petrochemical oil paints. Natural oil paints are a whole different breed. The emulsified oil paints are the most straightforward natural paints to use, and give results that are consistent with modern petrochemical paints. Washable, durable and tinted to any available colours, these paints can be used to replace conventional acrylic and alkyd paints with no change to expectations about application, coverage and durability. All the brands we’ve used are non-toxic and fully bio-degradable. Most can be obtained in just about any imaginable tint.

Auro Wall Paint, available in Canada from Tockay
Allback Linseed Oil Paint available in Canada from Living Rooms
AFM Safecoat Naturals available in Canada from Living Rooms
Kreidezeit Wall Paint, available in Canada from Tockay

Lime Paints

  • Calcium carbonate binder, often with additional natural binders
  • Indoor use (outdoor use for lime washes)
  • Most wall substrates, surface prep may be req’d

Lime paints have been used for thousands of years, and the modern versions are excellent products that can be used on most wall surfaces. Naturally anti-septic, these paints come in a variety of textures from quite smooth to quite grainy. They add a depth and beauty that is hard to explain but is immediately obvious upon seeing them. They are durable and do not wash away with water. They are an excellent choice for any wall that receives light to heavy contact, and are available in a wide range of colours.

Kreidezeit Lime Paint, available in Canada from Tockay
Auro Lime Paint, available in Canada from Tockay

Clay Paints

Non-toxic paints

Kreidezeit clay paint can be brushed or rolled onto wall surfaces primed with a casein primer

  • Natural clay binder, often with additional natural binders
  • Indoor use only
  • Most wall substrates, surface prep may be req’d

Clay paints are the champions of low-impact and low-toxicity. The fact that they are gorgeous to look at is an additional bonus! A variety of grain sizes and tints are available. They are durable (no dusting, will not brush off the wall) but are not washable. They can handle some direct wetting, but will wash off with scrubbing or constant abrasion. Good for use on any wall that does not receive direct wetting or a lot of touching/contact.

Kreidezeit Clay Paint, available in Canada from Tockay

Casein Paints

  • Milk or vegetable casein binder, often with additional natural binders
  • Indoor use only
  • Most wall substrates, wood

Casein paints can be made from vegetable or milk casein. Similar to the clay paints, they are capable of dealing with some wetting and abrasion, but shouldn’t be used in places where this will happen consistently. A wide variety of tints are available. They can be used on walls, and also on raw wood.

Homestead House Milk Paint, available from Homestead House
Kreidezeit Vegetable Casein Paint, available from Tockay

Mineral Paints

Non-toxic paint

Eco-House silicate dispersion paint can be used on interior and exterior mineral surfaces

  • Potassium or sodium silicate (“waterglass”)
  • Indoor & outdoor use
  • Mineral substrates only (plaster, brick, concrete, etc)

Silicate dispersion paints are unique in that they don’t coat a surface, they mineralize onto the mineral surface and become an integral part of the surface. This makes them extremely durable. We use them a lot as a finish for exterior plasters, where they have the Goretex-like effect of protecting walls from bulk water penetration, but maintain the permeability of the plaster. They can be used indoors or outdoors on any surface that is mineral-based, including clay & lime plasters, concrete, brick, stucco and stone. They come in a wide range of colours, and colour matching is available.

Eco-House Silicate Dispersion Paint, available in Canada from Perma-Tint

Non-toxic Clean-up
One of the unsung benefits of using any of these paints is that they are all biodegradable. Even the “cleanest” conventional paints have a petrochemical base that ends up in waterways or in soil during cleanup, with an aggregate of thousands of gallons entering the ecosystem annually. Natural paints clean easily and the wash water can safely go into septic systems or onto the ground.

So Many Viable Options
All of the paints listed here are products that we have used with excellent results. Each type of paint has specific uses and surfaces, meaning there is no surface in or on a home that cannot be treated with a natural paint. Costs tend to be slightly higher than mid-range conventional paints, and in line with higher-end conventional options. None of these paints are unaffordable, and the slight extra cost is a small price to pay to be surrounded by non-toxic surfaces that are not off-gassing into your home, and did not have a deep impact on the environment. A worthy investment for any home!

Want to Try These Paints?
Endeavour’s Eco-Paints workshop is a day long opportunity to learn all about natural paints, and to actually use all of the paints mentioned above.

The Art and Science of Natural Plaster DVD Now Available

The Art and Science of Natural Plaster is a 140-minute DVD created to help homeowners figure out how to use natural plasters on their own projects, created and narrated by Chris Magwood of Endeavour Centre. The
DVD is now available for purchase through PlasterScience.com in hard copy or online streaming formats.

Produced by Bart Glumineau, a graduate of Endeavour’s Sustainable New Construction program in 2013, and co-founder of PossibleMedia.org, creating original video content to share the stories of individuals and groups of people who are actively engaged in creating a better, more sustainable future.

The DVD covers base coat and finish coat mixes and applications that are suitable for a wide range of sustainable and conventional wall surfaces, from cob and straw bale to drywall. Chapters include:

  • Introduction to Plaster
  • Types of Plaster
  • Substrates and Substrate Preparation
  • Mixing
  • Tools and Trowels
  • Body Coat Application
  • Finish Coat Application
  • Paints, Washes and Sealants
  • Repair and Maintenance of Plasters

Much of the hands-on footage for the DVD was filmed at Endeavour’s 2014 project, a straw bale office building for the local teachers’ union.

We are excited to have some of our teaching and methodology presented in an accessible video format, and hope that the DVD inspires more people to take up natural plastering on new builds and renovation projects!

Thatch roof update

In 2009, we undertook the first permitted thatch roof in Ontario as part of the Camp Kawartha Environment Centre on the nature preserve grounds at Trent University. This roof sits atop a timber framed entryway for the building and greets all those arriving at this busy public building. The roof is nearing the end of its fifth winter, and a hike along the nature trails near the building gave us a chance to inspect the thatch under a blanket of snow and find that it is still water-tight and holding up very well.

Thatching is a roof system that has ancient origins and is still widely used in a modern context… just not in North America. Only a small handful of buildings on this continent have thatched roofs, and the skill set is extremely limited. This despite the fact that the material for thatching roofs is a widely available invasive reed known as phragmites (or elephant grass). An abundant supply of these reeds grows along many highway medians and ditches.

Thatched roofs exist in a wide range of climates world-wide, with the northern European roofs in countries like Denmark and Germany most closely representing Canadian conditions. In these places, thatching typically lasts 40-70 years, an impressive improvement over the commonly used 25 year asphalt shingles.

The actual process of thatching a roof is a bit more labour intensive than conventional shingling, though experienced crews in Europe move a rate that is not far off conventional practice here. For our project, the manual harvesting and preparation of the reeds was the most labour-intensive aspect. This would be quite easy to mechanize (as has been done elsewhere in the world), which would make thatching a much more viable proposition in this part of the world.

Given that the material for thatching grows annually, for free, along our highways, and that the environmental impact and working lifespan of this type of roof are far better than conventional options, it would be great to see more thatching happening in this part of the world.

Building bottle wall features

Many natural buildings feature bottles incorporated into walls. Bottle walls add colourful light and whimsy to a wall and open up all kinds of great design possibilities.

Here’s a little “how-to” guide to building your own bottle wall. It’s quite an easy process, and is applicable to interior walls and renovations as new buildings. Your own creativity is the only limit when it comes to using bottles in your building!

Rocket mass heaters with Andrew Brunning

I have lived almost my entire life in homes that have been heated with wood in one way or another. From a giant wood furnace in the basement of an old Ontario farmhouse to an elegant little pellet stove in a city home in Peterborough, I have enjoyed the process of burning wood to keep warm.

Rocket stove revolution

With this kind of background, it’s no wonder that I have followed closely the development of “rocket stoves” over the past decade. From their beginnings as a means to provide efficient cooking heat from minimal fuel in developing countries, the promise of rocket stoves has been intriguing for any wood burning enthusiast. However, the open “J-tube” style of most rocket stoves meant that the feed tube for the fire was open inside the home with all the attendant dangers. In addition, the wood used in J-tube stoves is small dimension, which is perfect for cooking where fuel is scarce but as a home heating device means constant attention and stoking is required. For these reasons, I have been hesitant to recommend rocket stoves as a home heating system, except for the strong-hearted devotees of the idea.

Rocket mass heaters – suitable for indoors!

However, the development of “rocket mass heaters” brings the rocket stove idea to the point where it is a feasible home heating device. This style of rocket stove blends the safety and efficiency of the masonry heater with the do-it-yourself approach of the rocket stove. I was privileged to be able to take a workshop on building rocket mass heaters with Andrew Brunning of Rocket Mass Heaters.

The design of the rocket mass heater, or batch box rocket stove, was developed by Peter van den Berg, and its genesis is explained in this article in Permies. The heater combines the simple construction and burn characteristics of a rocket stove with a full masonry burn box, as with a masonry heater or typical wood stove, which can have a closed door with or without glazing. One fill of the burn box equals several hours of burn time and many more hours of heat from the mass built around the stove.

How to build a rocket mass heater

The workshop with Andrew allowed the participants to help build the rocket mass heater, as well as the large mass bench that would be the recipient of the heat generated. The photo gallery below gives a good overview of the process:

Rocket mass heater workshop coming to Endeavour in 2015

I look forward to building one of these rocket mass heaters for myself. And Endeavour looks forward to bringing Andrew to the school in 2015 for a hands-on workshop!

How to build with earthbag

Earthbag building is one of Endeavour’s favourite building techniques. We’ve used it for foundations on many projects, and have built an entire buried root cellar with this material.

We’ve put together our experience with earth bag in a photo series. We hope it inspires you to consider this choice for your next building project!

Building with Hempcrete or Hemp-Lime

A group of lucky participants was treated to an excellent weekend workshop on building with hempcrete (or hemp-lime), led by UK architect and hempcrete pioneer, Tom Woolley. Tom is the author of Hemp Lime Construction and Low Impact Building, and has been involved in many hempcrete and sustainable building projects throughout the UK.

The weekend began with a classroom session, during which Tom covered the materials and techniques for successful hemp-lime building, and showing the group photos and details of a variety of building projects, including his charming hemp-lime cottage.

We then moved on to making some sample mixes to demonstrate the combination of materials. We were working with two different mix types, and made a sample of a third type of mix. For all three mixes, the weight ratios of materials were the same:

  • 1 kilogram of chopped hemp hurd (also known as shiv)
  • 1.5 kilogram of powdered binder (natural hydraulic lime or hydrated lime and metakaolin)
  • approximately 1.5 kilograms of water

The chopped hemp hurd or shiv needs to be fairly course (particle sizes ranging from 1/4 to 1 inch) and be relatively dust- and fiber-free. We were able to source Canadian-grown and processed hemp hurd from Plains Hemp in Manitoba.

Most UK-based hempcrete builders work with a natural hydraulic lime (NHL) as the basis for their binder. There is no North American source for NHL, so it tends to be expensive to import from Europe. We used an NHL 3.5 from St. Astier as one of our mix options. For a more locally-sourced version, we used a typical North American hydrated lime and a fired kaolin clay (called metakaolin) called Metapor. The NHL is a lime that chemically sets (hardens) through a reaction with the water content of the mix. North American hydrated lime does not set hydraulically (with water), but when mixed with a pozzolan like Metapor the two materials together have a hydraulic set.

The dry ingredients (hemp hurd and lime) are mixed together so that the powdered lime is covering all of the hemp, and then the water is introduced. Having done some work with hempcrete at Endeavour, we were surprised at how little water Tom uses in his mix. The final mix is just moist enough to lightly hold together when squeezed in a hand.

With some small scale mixes placed into test cones, we then moved on to installing hempcrete in some larger wall panels. These panels were built by Sarah Seitz for her PhD research work at Queen’s University, where she will perform tests to help determine the thermal insulation properties of hempcrete.

The panels simulate a typical double-stud construction, with a 2×4 frame on the “exterior” side of the panel and a 2×3 frame on the “interior” side.

As one group mixed batches of hempcrete in the mortar mixer, the others placed it into the forms and lightly tamped it into place. As the forms fill up, they are moved up the wall. The hempcrete retains its shape after less than 20 minutes in the forms. The filling and tamping continues right to the top of the wall. Once everybody was settled into their roles, it took less than 1.5 hours to fill a whole wall form.

In the end, we placed 40.25 cubic feet of hempcrete into the two walls. We used seven 40-lb bags of hemp hurd and seven bags of powdered ingredients to reach that quantity. With the small amount of water used in the mix, we’re anticipating a drying time for the 14-inch thick walls of about 2 weeks. This is much shorter than for the wetter mixes we have made in the past.

Cost-wise, we used $63 of hemp, $42 of hydrated lime and $21 of metakaolin, for a total material cost of $3.13 per cubic foot of insulation.

We will share Sarah’s thermal testing results when she has completed them. We are expecting to find their performance to be around R-2 to 2.5 per inch, meaning that our 14-inch wall would surpass current code requirements for thermal insulation.

This was a fun and informative workshop, and we’d like to thank Tom Woolley for sharing his deep knowledge of this subject with us!

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