Hello, from Turtle Mountain – and our Solar Powered, Rammed Earth house build. Time to reconnect.
Our family lost this wonderful house and the home we lived in for the past 25 years to a fire. 1 June. Yes, it was a big blow. But fortunately we have an amazingly generous community – and – we had the guesthouse to move into. Maggie always said about the new house we’re building that we wouldn’t move in until every detail was taken care of – “No skill saw running in the new place!” But she’s decided to pull back from that standard. We’re aiming to move in before winter so we can return the guesthouse to our potential guests.
All summer, it seems, we fussed with the Earthen (or sometimes called Clay) Floor. We wanted a floor that worked as a heat sink (absorbing warmth from the sun coming in our windows) but neither of us like tile or concrete under our feet. We went to see the earthen floor in a home of folks we know and fell in love. Little did we know that the path we were choosing would be so difficult to navigate.
We created samples with varying amounts of clay, sand, wood fiber (from planing our ceiling boards) and dried horse manure (yep, makes the mix silky smooth) – and of course water. We learned that the mix was best spread and troweled at a cake batter consistency. Our samples showed that the following mix was the easiest to trowel and did the least cracking as it dried. 3 parts sub-soil (which at the build site is about 70% sand and 30% clay), 1 part wood fiber and 1/2 part horse manure.
We did the sun room with this mix but found it cracked quite a bit as it dried. We called the Queen of earthen floors, Sukita, who suggested that the mix needed to be sandier. We imported builder’s sand and called in a flurry of family and friends for a day of lifting, mixing and spreading. Fortunately we have an old cement mixer that cooperated with the solar panels to do the hardest part. Dave and Jonah were on this outside work.
Here Robert (the only one ‘qualified’ to run the wheelbarrows) and Marcel make sure the soil mix is dumped and spread in what will be the kitchen. This final layer is about 1″ thick. It’s important that the sub layer (which is about 5 inches thick and holds the in-floor heat pipe) is tamped well and level so that the thickness of the wet mix we were putting on was easy to judge.
Wes and Cal troweled the mix to the point where Sven could add the finishing touch. The beauty of a soil mix is that, unlike concrete, it dries slowly, so there’s no panic doing the final trowel work.
All went well – temporarily. We got the floor done in what we estimated as record time and congratulated ourselves with refreshments and Maggie’s home cooking. Over the next few days, the floor dried and cracks appeared – some thin, some cavernous. It took a few days out of Maggie’s and my life and a week or so out of Sven’s but we got on our knees and filled those cracks with more of the same mix. It was tedious and defeating, because once the crack filler dried, the cracks reappeared – a lot thinner but still needing attention. Nothing we found on line or in Sukita’s book, prepared us for this.
Eventually we conquered, painting the floor about 4 times with linseed oil – which serves to darken and harden the earthen mix. The floor looks like a turtle shell and feels like cork. Perfect, but Sven was convinced there had to be a better way. The recurring quip was ‘Wait till I write MY book. This will be chapter 42.’ We knew that the water in the mix was the problem, so he experimented in the sun room, again, with a much drier mix, packing it in place. This worked better although the end result was not as smooth as we wanted in the main house.
Ever persevering, Sven wanted to try one more idea in the bathroom – drying the soil mix completely and mixing it with linseed oil. What resulted stunned us. No water in the mix and so no cracking! The look is more granular but feels smooth. It takes more oil to do it this way but cuts way down on the labour. Genius!
Thanks for paying attention to this. Let me know if you want a more technical breakdown of our research/experimentation.
And please feel free to come for a look and a visit. Text me at (204) 305-0528 or email firstname.lastname@example.org or message me on facebook – or just drop in. Maggie’s back in school but Sven and I are almost always at the build site.
If you want to help with siding the house and shop, we’d love the company.