The Timber Frame

The support structure of the house is a traditional wood jointed timber frame.  This post and beam style of framing easily suits the in-fill strawbale walls and lends it’s simplistic beauty to the interior of the house.  Colin worked with Garrett McLeod, a Pender woodworker and friend to design the structure of the frame to fit the shape of the house that Colin designed.  Instead of the traditional barn shape with a peaked roof that appears in most timber frame designs, we wanted a single level design with more of a japanese tori style configuration, allowing for the gentle curve of the living roof in the front and the shed style roof of the back half.  Garrett’s website-  www.macleodtimberframing.ca/

The Douglas Fir beams for the frame came from Gary Bruce, a wood timber salvager from Vancouver Island.  He delivered our order on his flat bed truck right into the temporary tent of the work zone.  We used 6×6 posts and 6×8 beams, with the main center beam being a beefy 8×8.  The engineer we called on to approve the structure determined that we wouldn’t need to use any knee braces with these sizes, but we threw in a few corner ones anyways.

Garrett and Colin worked on shaping the joints from the end of August, 2008, until they began putting up the first posts in the beginning of October.  The skill and efficiency that Garrett brought to our project was highly admirable and appreciated.  He had just finished a timber frame course at The Island School of Building Arts, on Gabriola Island,  www.logandtimberschool.com/.  Colin used his own skills from the  joinery that he uses in his woodworking business as much as possible, although the mortise and tenon cuts were of a much larger scale!  The whole frame went up in 6 weeks, using only a hand-crank frame that Garrett built to hoist the horizontal beams into place and so keeping with a completely engine-free process.  We did use Colin’s pick-up trunk attached to a block and tackle to lift the north wall bent all in one go with a few helpful neighbors, just like an old fashioned barn raising.  We love the beauty and strength that the timber frame has given to our house.  With the bales wrapped completely on the outside, the timbers are completely revealed against the walls on the inside of the house.  The beautiful honey colours of the fir were enhanced and sealed with a natural wood finish called Land Ark, which contains beeswax, tong oil, linseed oil, citrus extract, and pine rosin.  Land Ark is made with only natural, non-altered ingredients from sustainable resources, without chemical processing, bleaching, or harmful additives.  We have also used it on the door and window trims, the baseboards, and the ceiling boards.  It actually feels great to get on my skin, and I love the smell of it as I have done much of the staining.  For more info on a great product-www.landarkwoodfinish.com

The art of timber framing has a long and wide spread history of building, and we are very proud to have been able to utilize such a naturally complete system of support using the simplicity of the integrity of the wood itself in the fantastic configurations of joinery.  Timber framing is another way of demonstrating that beauty and art can be a deeply integrated way of construction.  To honour  the trees’ offering to provide their wood for our shelter (even though it was reused), we gave our gratitude in a traditional ritual of nailing a young sapling to the finished frame.

Have Bales, Build Walls

Colin and I explored and learned about many alternative building materials, but strawbale construction was not one of them.  The closest we came to seeing them in use on the west coast was as a north wall in a hybrid house with a southern cob wall.  It made sense- cob being a poor insulator but with beefy, heat sink mass wall, and bales being great for insulation in places that receive little sun.  Strawbales have been reported to have an R value (insulation measurement) of anywhere between 30 and 60 (with code minimum being 25 here).  We also learned that such decisions should ultimately be made when the land is chosen and the building site has been  observed for weather patterns, with an open mind free from any construction type bias.  We first considered strawbales when we began asking around to people in our community, and found a few existing strawbale houses, and one friend in particular who has built with many different types of alternative materials.  Tracy soon became our walking resource.  (Yes, the same Tracy I mentioned in the natural plastering post.)

Our building site is perched on the top of a bedrock slope facing due south, but with a longer east/west side, so while we have full sun all year, we also need lots of insulation to capture the rays with as much passive solar practices as possible.  The rectangular shape of the space available between the outcrops of rock made the use of bales easy to apply.  The bales provide infill walls only, as we designed the timber frame structure to hold the weight of the roof, which extends out with a 2 and a half foot overhang on all sides to keep our rainy climate away from the walls.  All the strawbales came from Mitchell’s, a family owned farm on the Saanich Peninsula.  They had an excess of barley bales that year, and as we inquired about 700 bales needed for our house as well as for a workshop that our friends were building at the same time, they were happy to help with a reduced cost and extra arms loading them into the moving truck that we rented to move them over to the island.  We used the structure of our roof and timber frame as a place to stack all the bales together while we worked on a few things that needed to be in place before the bales went into the walls.

We constructed the toe-ups for the bales- a step of sorts that the bales sit on.  This is a path of 2×4 lumber on it’s side, bolted into the foundation, and filled with drain rock.  We heard of people using crushed glass (from recycling depot), or corks (lots of trips to the recycling depot!) or anything that provides fill with air gaps.  We also used these toe-ups as a course for our electrical wiring, running the wires inside the lumber then up to our electrical outlets that were posted at the required height up from the 2×4, and being essentially free standing from the bales.  We protected the wires from the drain rock with a small piece of rigid foam insulation.  We did this for a few reasons, the main reason being that the electrical inspector wanted to see the rough wiring before the bales potentially hid them from view, and we didn’t want to get partway through our wall stacking then have to wait for him to make his visit, which can be the case if wires are run between bales.  We also wanted to run the wires up the backs of the timber frame to the places that would need wiring up high.  We stapled strips of burlap all along the places where the bales would come up next to wood, and a strip of building paper on the outside of the burlap.  This was more for the plastering stage, but it was essential to do it before the bales went into place.   We then posted bamboo poles on one side of the toe-ups up to the height of the top beam.  This was to be a part of our exterior pining system.  After the bales were in, we placed bamboo poles on the other side then sewed them together with a giant needle and baling twine through the bales, inside to outside.  We also put in place all the window bucks, securing them to the timber frame and the toe-ups so that they would not shift with any settling of the bales.  This created more detailing of the bales around the framing, but we had heard stories of frames shifting out of square and plaster cracking, so we decided to go with the rigid framing to avoid potential problems.

Finally we started building the walls, and with lots of eager hands!  Many of our friends had asked to come and take part, so we invited anyone who wanted to help.  We had a rotation of 4 or 5 people everyday for the week that it took to fill in the walls.  Although it was now november, we had a beautifully dry and sunny week to work in.  We learned how to reshape the bales to fit smaller spaces, either with a small electric chainsaw, or by splitting them and retying them with that giant needle.  We used zip-ties to tie the bales together end to end through the baling twine, and the fact that the twine on the bales was so tight it was hard to slip a zip-tie under them was a good sign that these tightly baled bales would be good insulation and might not settle too much.

We were even able to incorporate the enthusiastic pleas of our little ones, giving them lots of jobs with the small bales we created for the small spaces, and with the continual cleanup of loose straw everywhere.  They mostly settled into playing on the constantly diminishing pile of bales, but it was with great satisfaction that I could say that our building materials double as a healthy play fort.  I was also grateful for our decision when I spotted flocks of chickadees foraging through the litter for seeds and nest building material.  I loved finding the occasional sprig of dried wild chamomile bundled up into our walls, adding an element of calm to the energy of the house.

The last job was trimming.    Colin used a grinder and gave every inch, inside and out, a careful haircut to get a smoother surface on which to plaster.  Then we did a bunch of stuffing- making little twists of straw and shoving them into any little cracks that are created between the bales or around the window framing.

I am really grateful for the process we went through that arrived at the decision to build with strawbales for this house.  It has been a satisfying experience all along, from the many people that walked in and smiled with memories of family barns in their childhoods, or the soft cushiony sound of the acoustics as we played music perched on bales as benches, or knowing that any excess will go onto my garden paths or as summer mulch.  It is a building material that fits beautifully into the harmony of natural world, and creates those wide, adoring window sills that frame such glorious views of the world we honour and respect. 

Natural Plaster

A large part of the strawbale construction of our house is the natural plaster system that closes in the bales while still allowing a flow of air to pass through, supporting a breathable wall system that is totally weather proof.  I am not going to pretend that I can write a whole how-to guide here on this post, but instead I hope to give a most complete account of what we did to our walls, and hope that it is helpful to anyone interested in taking on natural plastering, or it is interesting to anyone just curious.  There are many books, websites, people of knowledge, and workshops out there that can give accurate (and sometimes conflicting)  information, and we have taken these steps available to us for what makes sense for our situation.

We have been blessed to have with us in our community an experienced natural builder and good friend, Tracy Calvert.  She has been integral in directing our experience, and helping out with the attaining of supplies and tools.  She is especially experienced in the art of natural plaster and it’s many layers of applications.  Our first layer was covering the straw bales with  clay slip, which is essentially like splattering the straw with thick chocolate milk.  Messy.  We obtained the clay from a pottery studio on Mayne Island, it is the off cut pieces from the creations of the studio which were destined to be sent to the landfill.  Some studios take the effort to reconstitute these wastes back into usable clay, but it is an arduous task to reproduce good quality clay.  Many studios prefer to consider these bits unusable, and so having them picked up by natural plasterers is a positive move for everyone.  After soaking the clay, we mixed it up with a heavy duty paint mixer mounted on a drill, until it was thick and smooth.  My method for getting it on the walls was to splash it on with one hand, holding a bucket below to capture what didn’t stick while rubbing it into the fibre of the straw.  Whatever technique is used to get the slip on the wall is a good one, there really isn’t any wrong way.  I covered every visible straw bit of the house, inside and out, turning it a lovely shade of dark reddish-pink.  It then spent a whole winter like this.

Layer number two is a cob mixture of clay, sand and straw mixed up in batches by foot and pushed on the walls by hand.  We got local clay from a farm down the road who was excavating a pond, pit-run sand from a local quarry, and the shavings of straw from when we trimmed the bales to make the surface even.  A good test for determining the quality of the clay is to do a jar test- put some clay in a jar with water and shake it up, then let it settle.  This will show the ratio of silt to clay, and whether or not there may be too much silt in the clay.  Ideally, the less silt, the better.  We built a soaker pit from leftover bales draped with a solid tarp, and kept it filled with softened clay ready for using.  After spraying the walls to get the slip wet, we pushed on the layer of plaster, spreading it about a half inch thick.  We started in early spring with a birthday party for our 4 year old, inviting all his friends and their families- really, this layer isn’t very difficult to master and it’s lots of fun to do with friends.  I had home school plaster parties, ladies’ night plaster parties, and afternoons with a few friends and their kids playing nearby.  The inside and out was finally done by the fall.

I was able to get started on the third layer in April.  Tracy came for a morning and went over the variation of the cob mix- this time the ratio of clay to sand was 1:2, with one and a half buckets of finely sifted straw.  (I used a certain bucket for measuring, and went through a few mixes of experimenting with ratios before finally getting to the mix that cracked the least.)  The sand we used was a finer, washed sand.  This layer is applied with a trowel, and encompasses the task of sealing in the flaps of burlap that connect the bale walls to the timber frame.  (Since clay doesn’t stick to wood very well and shrinks when it dries, a strip of burlap was stapled to the backs of the places where straw meets wood, and so the clay doesn’t move away from the wood when it dries.)  The burlap has to be rightly stuck down, so we brushed it with more clay slip until it was nicely saturated, then we rubbed it in roughly with plaster before applying a smoothly troweled layer of plaster.

We also took the time in this layer to shape those beautiful big curves of our windows, sometimes building up the flares with extra plaster until the shape of the curve was formed to our liking.  This is also the layer into which any sculptural work can be done, which we all know is the best part of natural plaster and cob. Nana enjoyed contributing her artistic sculptural skills around the house.

I was much more careful about who I invited to help with this layer- I mostly took it on myself (although Taeven and Cedar both took on their own ways of plastering with the trowel so they could help out).  I had the help of a few friends who are artists (good hand-eye co-ordination) and who helped with the previous layer, so they had an idea of what the result was to be and they came many times to help, building up their experience of working with the plaster.  My own abilities changed so much with this layer as I worked around the house, that I have re-plastered much of the first area I started on, seeing flat spots on window curves and too much cracking in other places.

We also covered some of our interior walls with plaster.  In the mud room, we built a stud frame wall, then stapled expanded metal lath to the sides, filling in the middle with straw.  The plaster goes straight on the metal, in two layers to avoid any movement of the mesh beneath.

The final layer of plaster is yet to be applied, and will undoubtedly require a whole new lesson in natural plaster.  The outside will be a mix of lime, sand, and colour pigment, the inside coat uses finely powdered cayolin clay as its base.  We fine-tune the quality of our trowels with Japanese trowels.  There is more technique involved in applying the plaster to avoid lines showing up…  I am looking forwards to working with Tracy again to learn this new skill level of natural plastering.  The journey of using natural plaster on our walls has been long and enjoyable, I have massaged every inch of our house with friends, conversation, children, family, quiet musings, music, meditation, in the sun and the rain.  I have mixed every batch of plaster with the energy of my feet and legs, and with the soles of friends.

 

Our Strawbale Home

My husband, Colin, and I spent a few years previous to when we bought our land, checking out a variety of natural building projects- cob, stawbale, rammed earth, cordwood, houses, garden sheds, playhouses- in various states of construction, doing workshops and reading books about land development theories and off-grid possibilities.  I remember walking into peoples’ homes, finished or not, and wondering when I would be the one answering questions in clay dusted work clothes, passing on the vision of a beautiful and healthy living space.  A few weeks ago we hosted our house on the Pender Island Eco-Homes tour, and I was able to see myself in just that light as I greeted over a hundred people throughout the day.  It’s been 2 and a half years since we began the foundation, and 2 and a half years of living in a 23 foot trailer as a family of four in the mean time.  We have worked beside a huge array of friends and community neighbors of all ages, with many of our materials being locally sourced.

Buying into the land with us (and making the reality of the price affordable for us all!) is my mother Margaret, otherwise known as Nana.  Colin and I have always welcomed the idea of shared land buying and building- we researched and looked into the prospect of larger, intentional community style projects here on Pender before this piece of land presented itself in such a way that we could not ignore.  We asked around for anyone else who wanted to join in, but it seems to have worked out for us to get going with Nana and keep our doors open for future co-creators.  The whole design of the house involves two more small levels descending down the rock slope in front of the part we are currently building, which will be a level of bedrooms and a level with an open kitchen and living room for our growing family.  The section we started with is a 590 square foot suite for Nana with a 290 square foot shared art studio.  This strawbale house opens into a nice size mud room, with a door leading south to Nana’s kitchen, bedroom, and living room space all in an open format (the front section with the curved, living roof).  A door leading north from the mudroom goes into the art studio and utility room (back section of house with sloping metal roof).  There is a small storage loft above the mudroom that will serve as a bedroom for the kids while we are building the other half of the house in the future.  We chose to build the house in sections due to the fact that we are living in a 23 foot trailer, and Nana is paying rent down the street, and getting one section done faster so that we can move into it together is much more appealing than waiting even longer and stretching our finances further before getting something comfortable to live in.  Nana has been a great help with taking time with Taeven and Cedar, baking us bread and treats, making meals when we are working late, and adding her artistic touches when she can, as well as taking on any jobs she can help with.  She also manages to help plant, weed, or harvest in the garden.

Colin designed the floor plan himself with considerations of the passive solar capacities available through the south facing slope that we are building on.  He hired our friend Garrett (McLoed Timber Framing) to design and work with Colin on the traditional wood jointed frame.  We used beams salvaged from old bridge timbers by a company on Vancouver Island.  The bales were bought from a family owned farm in Saanich, and we are covering them with natural plaster- a foot mixed combination of clay, sand and straw which is then spread over the bales by hand, and then covered with another layer smoothed by a trowel.  A final coat of lime plaster will seal in the  whole wall system, keeping it breathable, dry and super insulating (Straw bales are reported to have an R value between 35 and 60!)  We have a hydronic in-floor heating system laid beneath an earthen floor, the final layer being yet to happen.  This past summer we had a fabulous work party to get all the soil up onto our living roof, and it is now planted with native succulents and other sedums that I have been propagating over the last 2 years.  I hope to be able to post our continuing developments as we work this winter, as well as describing in more detail of any of the steps we have already completed.

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