Installing shower head far from valve

[GatorKenD]

Hi all - I want to install my Moen 2590 shower valve on the back wall of my shower and my shower head on the front wall of the shower (7' away). There's no tub spout; this is a shower only.

I'm guessing that Moen's precise instructions regarding placement distances are related to backpressure between the tub spout and the shower head. But, thought it would best to ask here. Any problem with this arrangement?

One more: The install instructions make reference to "shower only." I assume I'll just put a plug in the tub port of the 4-port valve. I'm not missing anything, am I?

Thanks,
Ken

 

[Pmaru77]

I don't see anything wrong with that. Just plug the bottom outlet for the tub. Then it's just a simple valve. But I'm no expert.

 

[Sponsor]

 

[Terry]

Tub/Shower Moen instructions
Position the valve body 32 inches from the floor of the tub basin. The shower arm should be placed 78 inches above the floor of the tub basin (recommended installation of the shower arm is with a flanged elbow fitting – not included – and attached to a wood brace). The tub spout is to be no less than 6 inches and no greater than 11 inches below the valve. If installing a threaded tub spout, connect to the valve with 1/2 inch pipe or 1/2 inch copper tubing with a threaded adapter. If installing a slip-fit tub spout, connect to the valve with only copper tubing – no threaded adapter is needed.

For a shower head only, this doesn't apply. You're fine.
You can port from the shower side or the tub side on the valve. The tub side has more output, but shower heads are restricted anyway.
The unused port gets capped.

 

[Pmaru77]

"The tub spout is to be no less than 6 inches and no greater than 11 inches below the valve." Why is there a restriction of no greater than 11" below the valve? You have me worried. I installed the valve higher to make showering easier. My tub spout is 20" below the valve. Installation instructions do not mention how low you can go. but says to go no closer than 8" and that is probably because of the covers and esthetics.

 

[MKS]

I vote , air gap between flood rim and tub spout, that you didn't have above.

 

[Terry]

There needs to be an air-gap of 1" between the spout and the overflow level of the tub.
This was in an existing home and there is a pretty good distance down to the spout. It's the friction loss to the tub spout that is the worry. If the water doesnt' flow quickly, it will back up and out the shower head.

 

[MKS]

Thanks

 

[GatorKenD]

Terry - thanks for jumping in there! I didn't know there was more volume on the tub port. I'll take advantage of that.

 

[Jadnashua]

Having over 7' of pipe from the valve to the shower head will mean it will take seconds to see any adjustment of the water temperature to reach the showerhead. It also will mean that there will be a long slug of stored water in the line to clear out when turning it on. The water won't fully drain out of the showerhead. FOr that reason, some people put in a tub spout even in a shower only situation (some call it then a toe tester) to get the water the right temp before diverting it to the showerhead, and if you lay your pipe with proper slope, it will drain when you finish your shower. Then, the hot water only has to warm up the dry pipe, not flush out all of the now room temperature (or colder, if it's running through say the attic) water. A longer run also means it could cool off more getting to the showerhead, so insulate the line. Because of that slight cooling, you may end up using a bit more hot water in the mix to get the outlet your desired temperature. SO, there are subtle reasons to not make that run longer than needed, but they're not game changers as long as you are aware of them.

FWIW, all shower heads made since about 1993, and many started even earlier (like 1987) are required to flow no more than 2.5gpm...either port on the valve can flow more than that, so the flow and pressure should be more than adequate. Using the tub outlet may be easy IF your valve can be inverted, otherwise, that adds yet another kink in the line, and will make draining it almost impossible. Wouldn't make a difference if you used the toe tester spout. That also gives you a convenient place to say fill a bucket if you want to mop something.

 

[GatorKenD]

Hi Jim - thanks for your feedback. Most (but not all!) are all things I considered. The rationale for the splitting the valve and the head is in this 7' x 4' shower (w/ no door), I didn't want to have to walk in to the point you'd get wet when turning the shower on. I suppose you could have a daily ritual of having turning the shower head to one side before turning the water on, but that seems like daily hassle as compared to being to reach in the entry opening and turning it on. "toe tester" would be an option, but I'm not keen o the look of tub spout in there. Below is a sketchup of the configuration I'm looking at.

Total amount of pipe between the valve and head will probably be closer to 11' by the time you go up and back down. I'm assuming the amount of time needed to have the hot water coming out of the valve and displace the standing water in a 1/2" pipe over that distance would be pretty quick; seconds? (should have paid more attention in physics... lets see, 1/2" cpvc... that's going to be about 22 ounces of water in the pipe... 35 psi... doh!)

While I did assume it'd take a few seconds to move the water to the head, I was thinking of it just in terms of initially turning the shower on. After reading your post, it did occur to me that one other subtle impact would be a temperature adjustment while you were showering would take a few seconds of patience to see if you got your desired result. (one thing mitigating that is I'm a total cheap skate and keep my hot water temp such that turning the shower valve on full-hot falls in the range of "slightly too hot" to "just right" depending on which family member you ask).

There will always be some water in the pipe between the valve and the shower head. Even if I slope the pipe down toward the head once it gets overhead, there will still be the ~40" rise. This shower will be use multiple times a day so I assume that's not issue, but let me know if I'm missing something.

I know this is subjective, but is this a goofy idea that just isn't done?

Thanks!

PS - what's the difference between guy doing plumbing in NH vs a guy doing plumbing in FL? A: The NH guy thinks running a pipe in the attic will maker the water too cold and FL guys thinks it'll make it too warm

 

[Jadnashua]

If you don't slope the entire floor in the shower, it will pool near the entrance. That can make the entry a little messy, but still doable.

I have a couple of tutorials in that section...you might want to read them on showers. There are lots of ways to do it right, but lots more to mess up. I also suggest you check with www.johnbridge.com for questions on tiling and building your shower, except the plumbing aspects.

 

[GatorKenD]

Hey Jim - I will slope the entire floor. That not being reflected in that drawing is a limitation of my skills in Sketchup. I'm going to use a Schluter pre-sloped pan and linear drain assembly for the first 48" from the drain and deck mud to carry that same 2% slope for the remaining 30-ish inches to the back wall. Finishing with the deck mud will allow me to slope at the entrance of the shower down to the rest of the pan. And, I have a thread started on John Bridge's forum for this same project (and some previous projects).

PS - clearly you're not going to let me "bait" you about your cold NH winters

 

[Jadnashua]

I lived in Kuwait for awhile, and they had water storage tanks on the roof. For over 6-months of the year, we used the water heater as a source of cold water, and water from the 'cold' as our hot. It was really messy when you ran through all of the water from the WH tank that sat in the a/c apartment! Transition seasons were tricky, but we could only turn the wh back on for a few months of the year.

 

[rjbphd]

Hope you installing MOENTROL with gravity re circ line and you'll be a happy person.

 

[Plumber69]

Tub/Shower Moen instructions
Position the valve body 32 inches from the floor of the tub basin. The shower arm should be placed 78 inches above the floor of the tub basin (recommended installation of the shower arm is with a flanged elbow fitting – not included – and attached to a wood brace). The tub spout is to be no less than 6 inches and no greater than 11 inches below the valve. If installing a threaded tub spout, connect to the valve with 1/2 inch pipe or 1/2 inch copper tubing with a threaded adapter. If installing a slip-fit tub spout, connect to the valve with only copper tubing – no threaded adapter is needed.

For a shower head only, this doesn't apply. You're fine.
You can port from the shower side or the tub side on the valve. The tub side has more output, but shower heads are restricted anyway.
The unused port gets capped.

I'm pretty sure delta changed there distance specs. I know this is moen

 

[TallDave68]

GatorKenD,

I know this post is nearing 8 years old but I thought it was worth a try to reply. I am looking at doing the same thing across a 9' ceiling. How did this work out for you?