Things are heating up!

Last week we tackled the in-floor heating system, hot and cold water lines, and insulation. These were the remaining tasks before pouring the floor.

We chose a hydronic system, also known as radiant, as the primary method for heating the building. Hot water will be pumped through miles of PEX tubing under the concrete floor, heating both the shop and the living space. We will eventually install a boiler and pump, but for now we are just concerned with the tubing under the slab.

In preparation, Sam and I installed a layer rigid foam to insulate the slab from the ground below. (The heating tubes will sit on the foam, under the slab.) First, we covered the gravel surface with a vapor barrier to keep ground moisture out of the building. We used a thick green plastic material called “The Perminator”. It came in a 15 ft wide roll that we had to cut and piece together. The wind kept picking up as we unfurled it, so we quickly threw rocks on top of it.

We taped all of the seams with a fancy waterproof tape. We also used the tape to seal the cut-out areas around the pipes.

Then we laid the foam on top of the vapor barrier. It was still windy when we did this, so we gathered more rocks and heavy objects to weigh the foam down.

We tried our best to cover every square inch to prevent heat from escaping into the ground. This involved cutting a lot of foam. I don’t recommend tackling a large foam project in the summer when it’s hot and dry. Not only is the foam slightly reflective, baking us from all sides, but it also creates a lot of static electricity. Sam and I were constantly getting shocked. I jumped every time I picked up scissors or a tape measure.

The foam kept expanding and shifting, so we kicked the boards together to close the gaps. We eventually tacked the boards together with duct tape.

Since we hired a contractor to install the in-floor heating system, we had a deadline to finish the foam. We worked into the night a few times, but it wasn’t too bad. We were rewarded with nice sunsets that complimented the sea of purple.

We finished just in time for the arrival of Terry, our contractor. We could have installed the PEX tubing ourselves, but it was worth the expense to get help from someone with experience. Plus, we were in need of a break and desperately needed to do laundry. The jokes about my basketball shorts and Sam’s jean shorts were getting old.

The orange PEX is flexible but very rigid and difficult to work with. Terry and his son made it look easy and finished in two short days.

Sam and I marked out where the walls and cabinets would be, so Terry knew what areas to skip over. Then, Terry mapped out his route and started unfurling the PEX.

He zigged….

And he zagged…

He created a giant maze in just hours, stapling the PEX to the foam as he went along.

He had a snazzy staple gun so he didn’t have to bend over. Plus, it’s difficult to puncture the foam with plastic staples by hand. We tried.

All of the PEX lines start and end in the mechanical room, where the boiler will be located. For the interim, Terry connected the lines to each other and pressurized them with air. This allows us to see a pressure drop if any of the tubing gets damaged when we pour concrete over it.

While Terry was working on his maze, Sam and I set up the hot and cold water lines. Those lines also start and stop in the mechanical room. They run to all of the sinks and showers. We insulated the hot water lines with black foam tubes that looked like pool toys.

I made a temporary manifold for the hot and cold water lines (after a reminder of what a manifold is).

Sam filled the lines with air to keep them pressurized, similar to Terry’s system.

Hopefully everything works! We won’t be able to access any of the tubes once the floor is poured.