Pex abrasion clips for radiant heat floor

prairieburner

Hello!

I'm getting ready to run a radiant heat floor system using heat spreaders attached to the subfloor.

I've read it is suggested to use pex abrasion clips to help prevent damage while feeding the tubing. My floor consists of doubled 2x8s (original 2x8s that are 1.75" wide sistered to new 2x8s that are 1.5" make the joists 3.25" wide). Clips are made for single joists. I was thinking of cutting 1.5" pvc 3.25" to line the drilled holes.

What are your thoughts on this idea?

Thank you!

hot_rod

You want that large hole for pulling the tube through. Then add the isolators when the tube is installed. Most of the tube has a PE coating over the EVOH oxygen barrier.

Sharp edges in steel studs or joists you would want protection at each hole, for sure.

A un-coiler help get the tube straight before you start pulling through holes. Get the coils warm if you can, it helps soften them and makes turning the ends easier.

Kaos

You can use two rabbit ear suspension clips, one on either side. Drill oversize hole and put the clip body inside the hole. You only really need the clips for holes where the pipe will move like along long straight runs. At the end where the pipe just turns, you can run straight through the joist without clips.

"PE coating over the EVOH oxygen barrier". This bit from above is very important, if your pipe does not have it it will squeak no matter how careful you run it.

With double joists, this is a lot of ugly drilling. Make sure you have good tools that won't break your wrist and good drill bits. Speedbore type tend to be the quickest but easily damaged by nails, so have extra. Carbide teeth hole saws are better for larger holes.

mattmia2

Stuffing a piece of foam pipe insulation through the hole is another option.

hot_rod

This bit and one of these drills. Buy a small file and keep the "spurs" on those bits sharp.

This bit works on TJI and dimensional lumber.

You can drill a 1-1/2" hole about anywhere but use a drill chart

I prefer a corded tool for a lot of heavy drilling. Probably rent one from a Box Store

Screenshot 2025-02-02 at 7.49.48 PM.png

Screenshot 2025-02-02 at 7.50.41 PM.png

Screenshot 2025-02-02 at 7.51.54 PM.png

Screenshot 2025-02-02 at 7.55.59 PM.png

mattmia2

https://forum.heatinghelp.com/discussion/comment/1839866#Comment_1839866

I love that style bit. I just used one to drill a hole in my rim joist for some conduit for a transfer switch today.

prairieburner

Thank you all for your replies!

I have tons of experience boring holes in joists and make sure to stay 2" from top/bottom and no more than 1/3 depth.

What is your opinion of drilling 2 smaller holes, instead of 1 large hole, for when supply and return need to share the same space?

psb75

I believe you are not supposed to bore below the center line of a joist. Two inches from the bottom is not good.