Securing PEX in a Soffit

[Tyler Underwood]

Hi experts,

Well it looks like the guy who installed PEX for his basement bathroom supply lines before finishing the rest of the basement messed up. Unfortunately that guy is me. Three years ago, I finished the rest of my basement, holding on the bathroom to spread out the expense and give myself a break. Now that I'm finally getting to it, I discovered that my 1/2" PEX supply lines run further than 30' and the inspector is telling me I need to switch them out with 3/4". The problem is they run through a 20' soffit I can access at each end.

My questions are, can I secure the 3/4" lines to pre-existing drain pipes running the length of the soffit with cable ties to avoid having to cut up my soffit more than I would other wise have to? I have one ABS line and one PVC drain line that runs the full length from my mechanical room to my unfinished storage room, hung about 3" below the joists and I was thinking of placing the PEX in the gap between the ABS in the joints, zip tying the two PEX lines together and every few feet zip tying them to the ABS (would be easier than using clamps or hangers nailed into the joists). Would that be ok, or do I need to give up on finding an easy way out of this messy situation and just plan to cut up my soffit and replace the drywall after? If you have any suggestions, I'd love to hear them.

 

[Plumber69]

Why do you have to switch to 3/4

 

[Sponsor]

 

[wwhitney]

Now that I'm finally getting to it, I discovered that my 1/2" PEX supply lines run further than 30' and the inspector is telling me I need to switch them out with 3/4".

Sounds bogus, I suggest asking the inspector for a code reference on that.

Even if 1/2" is too small for the total run, it is certainly possible to leave the 20' of 1/2" inside the soffit and just switch to 3/4" on either side. That will get you a lot of the benefit of upsizing the whole run, and 100% should be adequate for a single standard bathroom.

If you can provide a bunch of data, there is a sizing calculation that can be done to determine the actual size required.

Cheers, Wayne

 

[Terry]

Could you place some 2" PVC or ABS in there and then push the PEX inside of that? Does the inspector care if the lines are bundled? Here that would be okay.

 

[Reach4]

Now that I'm finally getting to it, I discovered that my 1/2" PEX supply lines run further than 30' and the inspector is telling me I need to switch them out with 3/4".

1/2, 3/4, and 1 inch horizontal PEX are required to be supported every 32 inches. See https://www.uponorpro.com/~/media/Extranet/Files/manuals/plumbing/AQUAPEX%20Install_HB_10-05.aspx?sc_lang=en page 10.

Cutting through the drywall, screwing in screw-type Talons, patching the drywall, and repainting may be your easiest solution.

I was thinking of some kind of cradle frame that you would push across, but that sounds tedious to build and put in.

 

[Tyler Underwood]

Thanks for the ideas so far. I've got a few questions to ask the inspector now, but running the lines through PVC or ABS sounds like the way I'll go if he doesn't have a problem with it. Looks like it doesn't need to be secured as often (every 5.5'?) so might not have to cut into the drywall more than one or two spots.