PEX or red vine candy?
The lower level of our house will have a concrete floor with in-floor heating, also referred to as radiant floor heating. After an unexpected wait of a couple of weeks, the crew finally came. It now looks like we have large red vine candy swirled all over the floor.
What we really have is called PEX. This is a very flexible plastic tubing that has been around since a German scientist created it in 1968. The full technical name is cross-linked polyethylene.
This article, titled PEX 101, tells how this pipe is starting to be used by DIYers for home plumbing now, but it has been used for radiant floor heating since the beginning.
A PEX sandwich
The floor layers at our house go like this:
- gravel was spread over the dirt and packed down
- foam insulation was put on top of the gravel
- a wire grid was positioned on top of the foam
- PEX tubing was swirled over the grid
- concrete will be poured, encasing the PEX tubing
What the swirls mean
The PEX is laid out according to the rooms and walls, avoiding toilets. The radiant heat is known to melt the wax rings on the toilets and that is not good.
They try to keep all the lengths of tubing equal.
The PEX pipes are obviously spaced with careful regularity. That spacing yielded a familiar pattern, as it was the same as the pattern of shadows I saw for 25 years in the ceiling of our previous home, which had radiant ceiling heating with copper pipes.
In this new home, we could have had controls for controlling the temperature in each room individually, but the installer said that is a huge expense (several thousand more dollars) for very little effect. He said everyone just ends up setting everything to the same temperature and leaving it.
So, although there are faucets to adjust water flow to each room, it will all be on the same thermostat. The faucet manifold will be in a wall, but for now, you can see it sticking up oddly.
Won’t the PEX get squished by the concrete?
The PEX will be filled with water prior to pouring the concrete, to make sure it maintains its tubular function. Once the concrete hardens, the PEX will be permanently encased and protected.
Setting the thermostat
The final tuning of the radiant heating, including thermostat settings, won’t be done until we move in. Since the move in date is no earlier than October, the weather should be just right for figuring it out. Someone from the radiant floor company will be coming to help with that.
What’s after PEX and concrete?
The concrete is supposed to be poured tomorrow, as I write this on a Sunday evening. Then, framing is supposed to begin on Tuesday! That 3-D effect should be inspiring.
In the background, Greg and I have been guided to many shops to make decisions about things like faucets, cupboards, and countertops. It is nice to know the builder is thinking ahead.
We have also been told that after framing, he will walk us through to decide about things like light switch placement. He says it is just much easier to decide when the shape of the rooms is there.
I am stuck between feeling it is taking forever and there is so much to decide in so little time.