Today we finish up installing the foam, staple down the PEX tubing for the radiant heat, and set up the manifold. Also, the plumbers rough in for the shower, toilet, and sink!

We left off part 8 with the gravel compacted and most of the foam installed. Today it is time to start finishing it up.

If you missed my other article on all the parts I bought for this install, you might check it out first at the link below. I go in depth about the layout plan, the different parts I bought, and why:

Installing the PEX tubing for the radiant heat

TIP: You don’t want the lines crossing over each other. What I ended up doing was starting at the far left side of the manifold and the far back side of the shop then working my way back towards the manifold.

To buy or not to buy the plastic staple tool

There is a tool for installing these plastic staples. I took a bit of a gamble and decided not to get one because they are kind of expensive and I am kind of a cheap a$$. Instead I just bought the staple strips, broke them apart and installed them by hand. I wore gloves but still by the end had callouses on both hands and was pretty well worn out. My hands hurt, knees hurt, arms hurt and I was very much over it by the time I finished.

I’ll leave it up to you if you want to buy the tool or do it by hand. If you have friends / family that will come help then you don’t need the tool. If you are doing it by yourself like me then it probably wouldn’t be a bad idea to buy it.

I was putting in staples about every 2ft with extras on the turns. I had originally ordered 800 staples which in theory was enough, but I ran out of them on the last loop and had to order more at the last minute. If in doubt, order extras. Luckily Amazon had them to me in the next day or so.

Finishing Foam prior to Plumbers

At this point I stopped laying tubes so I could start preparing for the plumbers to arrive. I needed to get the hole ready and form built so they could put their pipes in for the full bath.

The reason I am building an inner form and outer form is to keep the top of the footing exposed so the concrete slab would be securely connected to the footings.

I am not a builder, just a dude that wanted a shop. The builder told me I needed footings under where the bathroom will be per city code. Since they had done many projects in my city, I took their word for it. I didn’t quiz the inspector whether it was actually needed but everything I have done so far has passed inspections and I have had no troubles, so I’m happy.

Plumbing Installation

Though the shower, toilet, and sink will be on the outside wall, we ran all of the feed lines through the slab that way there were no water lines in the outside wall. This should help prevent them from freezing.

IMPORTANT: At this point I stopped with the pipes still visible to wait for city inspections before covering anything up.

Scheduled a rough in inspection by the city for the next day. It passed just fine, the inspector was here no more than 5 minutes. One thing to note though is that the inspector did not care about the radiant tubes for the heated floor and didn’t need or want to look at them. I suppose since it isn’t potable water or drainage that it doesn’t matter, beats me.

The black plastic thing over the shower pipe is called a ‘plastic tub box’ which is the only way I could find them on Google. This was one of those plumber kung-fu things where they had one with them on the truck. I had never heard of them before, but they make it so you have about a 12″ square where you can adjust your plumbing around to hit the drain on the shower pan. They are thin plastic so after the concrete is poured you just cut it open with a box cutter.

Finishing up the Hydronic Tubing

TIP: If you do heated floors in a bathroom do NOT use a wax ring on your toilet as it can melt. They sell all rubber ones like the one below.

How to pressure test the hydronic radiant floor heating tubes

Note – at this point it was about 1AM the night prior to the concrete showing up and I was freakin’ exhausted. I got the system down to where I couldn’t hear/feel any leaks and wasn’t showing any significant bubbles with my soapy water spray at the manifold. At this point I gave up and called it a night. By the morning the whole system had gone from 60 PSI to ~30PSI which I consider a pretty small leak. Had I more time, I would have chased it down but since the crew showed up at 7am I didn’t really have a choice. I knew it wasn’t in the tubes though since there were no joints anywhere except the manifold. Good enough for now.

Thanks for reading. Next up we cover the concrete pour!

Now YOU, go outside and work on something!