It started off as a garage. A place where the mice danced in dusty corners amongst years of accumulated lumber, hiking gear, and things that we couldn’t possibly give to charity but that didn’t seem worthy of being sent to the landfill either. It had potential though, partially because it provided a space adjacent to the garden and partially because it was a space that most people had in their lives – messy, undervalued, a place for junk.
After coming up with a rough plan of the space we required – in this case about 1/3 of the garage or about 100 square feet – we began gutting the place. We pulled off old fiberboard and the 1950s newspapers that backed it; we pulled out the old shoddy wiring; and we removed the giant green garage door that hung on a pair of substantial springs that could remove a head if you weren’t careful. We also removed half a five gallon pail of nails. This place was built to last.
After a few dusty days we were left with beautiful old fir studs and a gaping hole where the garage door once stood. We framed up the opening to accommodate a decent set of used sliding doors we got from a contractor friend (thanks Ghaiss!) and we installed a nice big, and energy efficient, window from the discard pile at a local window manufacturer. We began assembling the Larson trusses – an alternative to standard wall studs that decrease thermal bridging, while giving you a nice wide cavity for plenty of insulation. These trusses would serve as the framework for our light clay straw wall, and this it where our building started to take on its natural character.
Natural building is characterized by its use of locally available, non-industrially processed materials. These materials are often readily available, extremely affordable, and have a very low embodied energy. Cob (a mixture of sand, clay and straw), adobe (mud brick), strawbale, light clay straw, wattle and daub, to name a few are all variations of natural building. Each has its strengths and weaknesses, making some more suitable for certain regions and climates than others. Cob has lots of thermal mass but little insulation, while straw bales provide plenty of insulation but have little in the way of thermal mass. We chose light clay straw because it offers the best of both worlds – good insulation and good thermal mass, meaning that it not only keeps heat in bit it can also store heat in its mass, releasing it as it is needed.
Light clay straw (a.k.a. clay fiber or straw clay) is simply a mixture of clay slip (clay rich soil soaked in water to the consistency of cream) and straw. The straw is thoroughly coated with the slip and packed into formwork around the Larson trusses. These walls offer good insulation, they’re vapor-permeable (breathable), and they regulate moisture extremely well. These variables are important because many modern buildings, with their air-tight construction and manufactured building materials, have notoriously unhealthy air quality. Natural building materials avoid these problems, improving air instead of degrading it.
The work is rather laborious but only if you do it on your own. Get the community together and it provides a great opportunity for people to pick up a new skill, meet new people and feel a great sense of accomplishment. So that’s what we did.
Over a one-week period we had several work parties where about 20 people came out to learn the basics of clay straw construction. The great thing about building with natural materials is that with a little guidance, relatively unskilled people can be taught to build with natural materials and do a fine job at that. At the end of a hard days work, we fired up the cob oven, baked pizza, shared laughs and rejoiced at the progress we had made…together.
A 9 inch thick clay straw wall now divides the garage into two spaces – a shed on one side and what will soon become a wonderful little chill space next to the garden on the other. We’ve since insulated the side walls and ceiling with 100% recycled cellulose insulation found on Kijiji and we’ve used some salvaged drywall to sheath these walls. Drywall is not a “natural” material but it is certainly prevalent in most every North American home. Our reasoning for using it was to demonstrate how even drywall can be made healthier with the application of clay-based paints and plasters. This will be covered in an upcoming workshop.
Heating will be done using a wood stove and just last week, we installed a Rocket Mass Heater – a super efficient wood burning stove that makes use of a 5 tonne cob bench to store the heat. You can read all about this project in the Rocket Mass Heater post, also in this month’s newsletter.
We’ll pull everything together with an earthen floor and the walls will be covered with a combination of clay paints and plasters for the interior walls, and lime plasters on the exterior.
All in all, it has been a great opportunity to take a derelict space and turn it into something beautiful, using only natural and reclaimed building materials. Whether it’s a full house, part of a house, an old garage or a garden shed, natural building can be integrated into your life for the better. Working with natural materials connects us to a rich and almost forgotten history and it connects us with the earth. Natural building nourishes us completely and there’s no better time to get involved.