Why Can T You Use Pex For Tub Spout Drop

If you use pex for the tub spout when you turn on the water to the tub water will back up through the shower head due to the reduced inner diameter of the pex it s called stacking.

Why can t you use pex for tub spout drop.

In areas that are concealed like under a kitchen sink or vanity cabinet you can eliminate a joint by running pex supply directly to the shutoff valve. 2 reasons i learned. With a built in diverter you could use a pex drop eared ninety degree female adapter and a nipple but that is more trouble than it is worth. Copper is the only professional installation material.

Original poster 4 points 3 years ago. A lot of manufacturers are very specific about this and i ve seen it hundreds of times. Long story short it is unacceptable. Copper would help give more support to the drop ear fitting and tub spout which is probably why they recommend it.

How did this project turn out. The interior diameter of pex is actually a fraction smaller than copper this forces water to come out of the shower at the same time as the tub spout. 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. You can connect a compression type shutoff valve to the one half inch copper stub out and then connect your fixture.