We decided to go with a tiny house and use a post and beam foundation. Again, our whole lot is ledge so we really can’t dig a foundation of any kind. We really don’t need to. The ledge provides a solid base to build the house on.
Frost heaves are the biggest issue here, and a solid piece of rock won’t heave. The idea of the post and beam is that you put posts in the ground and then the beams go across the posts to provide the base of the structure. All that has to be dug is the holes for the posts. In this case 11 posts. Not all of the posts even get holes dug, in our case that depended on making the ground level. Gravel is laid down in each of the holes or spots, insulation over the gravel, and then concrete pads over the insulation. Each pad will be for a post.
Forgive me if I don’t completely know what I am talking about. I am not an expert in any way. I am simply sharing the information that we have that has lead us down the path we are on to build the way we have chosen to build. We do have a professional helping us build though. We got lucky to meet somebody who was willing to help us along the way.
First step of our post and beam “foundation” is to flatten out the area where the house is going to go. We brought the tractor in and cleared out the brush and the smaller stumps. Then pulled some of the rocks out of the way. This may sound like a really easy job, but it took a long time. Working through large rocks tangled in thick roots tangled in hard clay has taken most of our time so far. (I say “our” but my job has been to keep the kids away from the spot until it is time for one of their “special jobs”).
Next thing we did was to dig the holes. We have 11 posts for the base of the house and so we need 11 bases set up. Even after flattening the land the best we could, it was far from level. We could not make it level with any kind of ease. However, it was only gently sloping so the bases that were on the high side were dug in to the ground. Five of the bases were dug in for our house.
Once the gravel is down, the insulation squares sit on the gravel. This is 2” thick scoreboard insulation. I tried to figure out what the point of this insulation is but I just cannot figure it out. The bottom is on the gravel, which is pretty much out in the open and can freeze. The top is covered but the concrete pad which is pretty well exposed and will also be able to freeze. I haven’t had a chance to ask the pro, but if anyone can fill me in, I would appreciate it. As the squares get put in place, the 2’x2′ squares were adjusted so they would fit pretty closely into the ground.
After they were placed, we did a preliminary level check to see if they were even close to flat. It is easier to level as much as possible before a concrete pad is sitting on top.
Put the pad on top of the insulation, level it out, and we have ourselves a “foundation”.
The kids always want to help us. We do our best to encourage this especially because they may not always be so enthusiastic about helping. When you are building the most important part of the house and you need it to be perfect, what can the kids possibly do? We had them fill the gravel in around the foam board. I’m not convinced it even needed to be done, but it satisfied them for a short while. I told them what a great job they were doing and pointed out how nicely they were working together.