Barn Design

It very quickly became obvious that the design of the Barn and the solar heating design are joined at the hip. I wanted to have solar heating so I needed to have curtain features in the design. The 60 degree south facing roof was the one of those features. As I looked on the internet for gambrel roof designs, I came across a beautiful set of barn plans from a company called BarnPlans.com (good name). They provided the plans for the whole barn and if I hadn’t already designed the rest of the barn, I probably would have used them. As it was, I only needed the plans to field-build 32’ trusses and the dormers. The trusses were built right on the second level floor and lifted into place with a winch. 

 Another feature that had to be built into the Barn construction was the under the floor heated sand mass. I picked the flattest piece of south facing ground that I could find on my property. When I surveyed it, even though it looked pretty flat, it was actually a 6 foot drop from the northwest corner to the southeast corner. That meant all of the dirt that was excavated out of the northwest corner was used to fill the southeast corner. So all of the material needed to fill the 2 foot stem wall of the footing would need to be brought in. This material was going to be my sand mass heat storage. I first lined the stem wall cavity with 2” extruded

polyethylene foam board to insulate to box. It must be extruded to have the capability of withstanding the weight of the fill material. The fill material is called sand but I only used a high quality coarse sand around the PEX pipes. The rest of the “sand” was actually road base gravel. It packed very well and is easier and cheaper to obtain. As they started to bring in the 200 tons of sand and gravel, I started to carefully place it in the insulated cavity. I first had to build a ramp into the cavity using the road base material. I used a very small bobcat skid loader to haul the gravel. After I created an adequate ramp, I would take the sand to the edge of the insulation and dump it carefully in layers until I had 12” of sand. That was enough to spread out the weight of the bobcat so that I could drive over the extruded polyethylene. I then wheel packed the gravel to create the base level of the sand mass. I laid out the lowest loops of PEX pipe and routed it over to a temporary wooden rack that would hold the PEX Lines in place until the cement floor was poured. I did, of course, mark each run but I should have written down a key as to where each line went since the marks on the rack were pretty hard to read by the time the floor was poured. Note also that the PEX lines were plugged, and one plug was tapped so a valve stem type fitting could be placed in each run. The PEX was pressured up to 50 psi or so of air so that it wouldn’t be crushed as I was working.