Unfortunately the pex roll was unweildly and as the first zone was unrolled, the pex became extremely tangled. The 1000 ft. roll came in a box and did not have a plastic sleeve to hold it in place.
Several crimps in the pex were the result of the tangling. The workers helped me untangle this mess outside on the long 300′ driveway. It took almost 2 hours to get it straight, and the crimps were straightened with a heat gun. The pex turns clear and the crimp “magically” disappears, although the pex wall is a bit wrinkled from the heating and cooling process. Then we pulled it into the house in a long straight line as zones 2 and 3 were laid. The pex was attached to the rebar with inexpensive 6″ zip ties with the tails pointed down so they would be out of the way of the cement.
This gap was left in the middle of zones 1 and 2 because both loops were over the ideal 300′ design length and the area in the middle of the room should not need much warmth. The gap will be under the wall between the dining room and the family room areas so it should not affect overall comfort.
Zone 3 is the shortest zone, it is also the zone with the most solar thermal heat transfer, so the living room might be a bit too warm, but we placed more than 12″ between the rows in the north side of this zone. We used exactly the rest of the first 1000 ft. roll of pex. One full 1000′ roll completed three zones, more or less as the plan indicated.
I read that if the pex is distributed vertically, that it will not tangle, so I scouted around for something to substitute for the $300 de-winding tool that is available for pex. I found a $30 motorcycle stand on sale at Harbor Freight and we ended up exchanging the clamps for pieces of rebar taped to the sides to hold the roll on the stand. Unrolling required one person to lift the roll from the stand and shake it as the other pulled the length needed for the next loop. This roll was used for loops 4 and 5.
This is the most complicated layout, in the reverse spiral pattern.
The inspector mentioned that the pipe was a bit close to the toilet drains and there was a chance that the warmth from the radiant pipe would melt a wax ring at the floor where the toilets were installed. I was going to move the pex, but I ran out of time and it seemed too difficult and dangerous to try to move the installed pipe. So I did some online research and decided the design temperatures for both the water (120 degrees) and the floor (85 degrees) were below the melting point of the wax ring (130 degrees). Also there are Fernco rubber rings that we could use instead of wax. Some plumbers prefer them over wax rings although some think wax is stickier and will last longer than rubber.
The manifold pipes are left over from the home’s previous boiler. Not sure that it will work with the new system but it seems like it should and trying this will save some money by not replacing the copper pipe and valves.
The return pipes were straightened out a bit before the pour, but it is obvious that the piping to the manifold in this corner is quite close together, with both the feed and return pipes in a relatively small area. It should be warm in this area anyway!
The insulated connections on the left hold the 3/4 inch radiator pipes for the rear of the house, these pipes are routed in 4″ plastic pipe under the waffle boxes and insulation. The 1/2″ hot water return is just left of the radiator pipes. The hePex is routed through 3/4″ conduit elbows where it leaves the cement. The two connections on the right each have two zones of pipe connected to just one thermostat so they are essentially one heating zone. I think the job looks pretty good at this point.