We were supposed to use rye straw for our insulation. We had harvested it 2 years ago from my dad’s fields (organic rye straw), had bailed it and stored it in the house’s cellars waiting to install it. Like with every project where innovative or uncommon construction techniques are used, our plan for the insulation system fell apart when we realized that the stone walls were not completely waterproof. During heavy rainfalls, moisture was appearing on the inside of the house along certain walls. It wasn’t like water was dripping but in a few places, it was seeping through the 50-cm thick stone wall and wet spots could be seen in several areas inside the house. Although rye straw is less prone to mold than wheat straw, it is still not 100{86faa949d09500cfb2fb8be01edc8582822a5980221f039bd4bbebd1d0646763} resistant against moisture and mould. After a lot of research and much worrying, we finally settled on replacing the straw with cork. Loose cork is a very good insulating material and unaffected by moisture. The challenge was that it is generally expensive and comes from Spain, Portugal or even further away. So we did more research and were very excited when we found a small business in Southern France (4 hours away from where we are) that recycles wine bottle corks and turns them into loose cork for insulation. Because there is a lot of volume in our house (20 cm of insulation all around), we practically booked the company’s supply for the next 6-month. Wine bottle corks are usually made of good quality white cork. There is a little bit of a wine smell but once tucked away between the stone and brick walls, the smell can’t be detected. Here are a few pics of the first delivery of cork and installation inside the walls.
After a lot of researching, thinking and worrying, we finally settled on an insulation system and wall structure which we hope will last, be risk-free and provide us with the insulation and temperature management ratings we were aiming for.
The solution we’ve opted for are hollow bricks typically used to build inside walls. To give more mass to the bricks (for better heat retention and management of temperature swings inside the house), we decided to fill them with a mixture of red clay-based soil (which we went to get 15kms away, on one of my brothers’ property), sand and lime-based cement. The mixture needs to be rather liquid so it properly fills all cavities of the bricks. Once dried, the bricks are slightly heavier but can be handled without one worrying about the soil pouring out of them.
Finally, the larch siding is being installed on the garage. There isn’t much surface to cover but because of the slate roof, it takes time to cut the planks so that they fit nice and tight along the slates.
As we are building the brick walls all around the inside of the house, we are installing at the same time the piping for the heat exchange venting system. We decided to place the two main distribution panels, one for all exhaust pipes (hot spoilt air) and one for intake pipes (fresh clean air), in the lower cellar, underneath the house. They will be close to the heat exchange unit and to the arrival of the earth tube system.
