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We just completed the radiant heat installation (or the part that we are capable of, at least). Later, trained professionals will be coming in to to install the manifold and fill the pipes with water. We’re pretty proud of what we accomplished ourselves here though. And actually, it wasn’t as difficult as we expected.

First, we screwed these specialty clips in the underside of the second level floor with 1″ screws. The shorter screws ensure that they don’t pop up through the sublfoor.  We spaced them every 16 inches in rows that are 6 inches apart from each other. We did not put clips (and therefore no pipe) in areas that are not meant to be heated such as under cabinets. By the end of the second day 1,208 clips had been screwed into place.

Once all the clips were in place, we began pulling the Pex pipe through the floor joists. We dangled one end of the pipe near the future location of the manifold and pulled loops of pipe off the spool. Each loop could not be any longer than 300 feet total in length (including the length it takes to return to the manifold). This is because we are doing a low temperature system to conserve energy and cost. Longer runs of pipe allow the water to cool and will cause inconsistent heating and possibly stress the boiler. So we started looping our pipe back and forth and clipping it into place, keeping an eye on the footage printed on the pipe. When we’d get down to a predetermined number of feet that it would take us to return the pipe to the manifold, we’d run the pipe back. Then we cut the pipe and taped it to its other end. We repeated this process 8 times. We found that spinning the spool helps prevent kinks better than flipping it. This was a valuable thing to learn because we actually had to start a loop over one time because we tried to force the pipe and caused it to kink.

Once we had successfully clipped pipe (2,124 feet of Pex pipe, to be exact) under every inch of floor we wanted to heat, we were ready to pressure test the system. There is always a chance that someplace along the length of pipe there is a manufacturer’s defect or damage caused during installation. And you certainly don’t want to discover a pin hole when the pipe is filled with gallons of water under pressure. Instead, air is used. With a special tool that stretches the pipe, Scott installed fittings and connected all the loops together. Then we filled the pipe with 100 pounds of air pressure using the air compressor. We left the pipe pressurized overnight and checked it the next morning, hoping that it had held. Much to our dismay, it had not! It had lost 10 pounds of pressure in the course of a few hours. We hoped that it was one of the temporary fittings that was losing air. Sure enough, after spreading soapy water over the fittings, we found that one of them was leaking. Thank goodness! Sow we replaced the fitting and re-pressurized the system, this time with success!

After drywall is completed, the radiant heat company will install the manifolds and boiler. Once we get to that point, we’ll explain more about the cool (or hot) features of radiant heat. For now, it’s back to work. On to electrical…