At the Cob house our priority has been getting the hearth in so we have a wood stove we can fire up on the coldest days and have hot lunches and keep ourselves warm! And once the hearth is in we will be that much closer to having a completed floor, another huge milestone.
The hearth is going to be mostly bluestone masonry floor with cast iron wood stove on top. Ryan obtained his cast iron wood stove for free from a friend who was replacing his. The stove is larger then necessary; perfect for cooking on but perhaps less efficient then a smaller stove would be as a source of heat. But it can easily be swapped out for another stove when Ryan is able to obtain another one more suited to the space.
In order to get to the point where we can install the wood stove we must first get the floor installed and ready. To do this we first created a basically level and smooth surface by taking out any rocks and rubble that had been temporarily filling the floor cavity, and laying down a layer of tamped gravel and then a thin layer of sand on top of that. Once there was nothing sharp sticking up that could poke a hole in our vapor barrier we lay down a sheet of heavy duty polyethylene plastic, a cheaper alternative to EPDM. EPDM stands for ethylene propylene diene monomer and is a type of rubber often used as pond liners or for living roofs. EPDM would probably be a bit overkill for a floor liner but Polyethylene is much more fragile and vulnerable to puncture. If you are doing a living roof and can afford it EPDM is definitely worth the extra money and will last longer and cause you less headaches. But for our floor we decided to go with the cheaper polyethylene. Once our polyethylene vapor barrier was down we covered it with another layer of sand to protect it from puncture from above. With vapor barrier sandwiched in a protective layer of sand we poured and tamped gravel to fill the rest of the space and bring it up almost to the level of the floor. Then it was time for some masonry work: stone laying time!
To be honest, I don’t like working with stone. I find it tedious and frustrating; It’s really hard to cut and manipulate stone the way you can with wood without it looking fake so you have to painstakingly find the stones that have a pretty good natural fit. But that is just me. Ryan, on the other hand, loves working with stone. After an afternoon of playing with stone configurations we may have our layout for the border of the hearth. Maybe… But we do at least have our first stone in!