Hello,

I was planning on using PEX pipe from bath fauct to tub spout but delta says just to use copper. I am planning on using drop ear that will be supported for spout section. Anyone know reason why they advise not to use PEX in this section? As far as diameter would 3/4 be better than 1/2 inch pex at this location if i decide to use it?

Thanks!!

 

I'm certain they do not want you to use PEX from the drop ear to the tub spot but you could probably use it between the faucet and drop ear. Copper would help give more support to the drop ear fitting and tub spout which is probably why they recommend it.

The tub spout either screws onto a male pipe thread which is sweated onto the end of the copper pipe or it slides over the pipe and has a set screw to hold it in place. In both cases the strength of the copper pipe is needed to support the tub spout. If you used PEX the tub spout would always be somewhat movable and not rigid.

 

There is a very good reason not to use PEX or CPVC coming out of the valve and down to the spout: The ID of either of those is quite smaller than the ID of 1/2" copper, or 1/2" sch. 40 brass or galv. nipples. The smaller diameter increases the backpressure such that you will tend to get dribbling out of the shower head even while running the tub spout.

This symptom gets reported on a regular basis on the various plumbing forums, and the answer is as I described. IT IS THE REASON that all the manufacturers specify to NOT use the plastic for that connection.

 

Is it OK to use 1/2" PEX from faucet to shower head ?
Just wondering, if I had 3/4" PEX would it be ok to use it from faucet to spout?

Thanks.