Sharing our wooden yurt building experience and more.
We were very excited the week they put in our foundation for our 840 sq. ft house. It finally went from concept to reality. These photos are from over the course of a week from Sept 6th – 15th, 2014. Sept 15th being the day the actual foundation was poured. Being this was the only time we’ve ever built, we started off by not realizing what went into a foundation. We thought it was strictly concrete. We had no idea about the form they had to build. Since ours is a very particular shape they had to customize it quite a bit. No square house for us. Unfortunately we found out too late that they lay a layer of plastic vapor barrier between the foundation and the gravel. As well as PVC pipe around our copper piping. As this was the first thing to go in and we were unprepared, there was nothing we could do. So our no plastic criteria was out the window on day one, so to speak. We knew we would have to make some compromises and we had to be ok with that. We eventually found out that for this part of the building, unless we were willing to put the project on hold to attempt to talk the county into accepting greener materials, it wasn’t going to happen. Code doesn’t allow for anything other than what we used for our situation. We picked the greenest things we were offered. Folks in CA went through the same thing and it took them 6 months! There was no guarantee it would happen for us and we didn’t even know anything about it at the time. We couldn’t afford to put anything on hold as we were racing against time to put in the septic before the Pacific Northwest winter rainy season.
This post is about how a slab on grade foundation gets put in and how the plumbing is put into it. We thought a truck full of concrete just gets “dumped” into the form. But no, it’s more complicated than that. We didn’t even know that it is a separate company that supplies the concrete. They show up first and then the truck transfers the concrete to another truck that has a long crane like thing with a hose on it. The hose is used by the foundation workers to very easily fill the areas with pinpoint precision. (As opposed to dumping a boat load on the whole slab.) Then they work like a well oiled three person machine (as in our case) to fill in small areas at a time while one fills, the others rake it smooth. Then other tools and machines are used to finish it to a very smooth surface until it has set. They were able to walk on it even before the end of the day. They had us hose it off as it was hot that day and you want it to set slowly as the slower the better, harder and more stable it is. Hot weather makes it set faster. We originally planned on adding up to 15% fly ash to the concrete but it became too complicated to get the fly ash onto the island. The fly ash is left over from coal plants and by adding it you use less cement and makes the slab stronger. A large portion of green house gases is from making cement.
We used this type of foundation because we had a high water table on our land. Now the house will sit above the ground to prevent potential problems. We had to wrestle with knowing the cement industry is part of the green house gas problem.
Zellerhoff Construction on Vashon Island – Excavation and gravel
Sound View Construction from Port Orchard -Foundation form and slab on grade
Olsen Concrete Pumping on Vashon Island – Concrete
Gravel (Vashon), XPS insulation (Canada), Plastic vapor barrier (origins unknown), Rebar (Made in USA), Portland Cement (USA)