DIY ceiling mounted rainfall shower head addition

[Ryan98270]

Hi all!

Hoping to get advice on how I should run this setup. Mostly getting confused on the valve choices.. The shower is currently opened to the studs and we wanted to take this opportunity to add a rainfall shower head in the ceiling. Its a shower only and currently plumbed for a single 45° shower from the wall. While adding this rainfall showerhead we were hoping to not lose water pressure, and having both at the same temperature would be a bonus, bus not at the expense of water pressure. 1/2 inch lines. Planning on moving the current light and installing it there, directly above the drain. Finish will be brushed nickel fwiw.

My plumber mentioned using Delta 1700 series? Not finding much on it

Any recommendations on valves, plumbing route, fixtures etc greatly appreciated. Im a newb, but you all helped me through my single to dual sink vanity project in this same bathroom.

 

[Ryan98270]

Hi all!

Hoping to get advice on how I should run this setup. Mostly getting confused on the valve choices.. The shower is currently opened to the studs and we wanted to take this opportunity to add a rainfall shower head in the ceiling. Its a shower only and currently plumbed for a single 45° shower from the wall. While adding this rainfall showerhead we were hoping to not lose water pressure, and having both at the same temperature would be a bonus, bus not at the expense of water pressure. 1/2 inch lines. Planning on moving the current light and installing it there, directly above the drain. Finish will be brushed nickel fwiw.

My plumber mentioned using Delta 1700 series? Not finding much on it

Any recommendations on valves, plumbing route, fixtures etc greatly appreciated. Im a newb, but you all helped me through my single to dual sink vanity project in this same bathroom.

Looking at delta r22000 with trim for 3 way use (A, B, A+B) and running pex up to the attic then over to rainfall location. Do I have to elbow it once in the attic or can I do a a couple alow radius bends with those plastic pex benders (to try to minimize pressure loss). Does the pex have to stay within the framing cavity or can I run it over a joist in the attic if needbe?

 

[Sponsor]

 

[Jadnashua]

If you want to run both heads at the same time, you will need to use the tub outlet of the valve. The shower outlet is flow restricted, and you will see a reduction - good for one, not for more. Using 1/2" pex is already a restriction over copper, so it will be close with two heads running. Shower heads work as designed when they can get the full or larger flow than they were designed for. A rain shower head usually doesn't get any acceleration and is just relying on gravity, so don't expect any real pressure from it. When the outlet can't easily flow the full amount on the inlet, it tries to accelerate through the jets...that's what creates the extra pressure...not enough volume, no acceleration, and the feel of less pressure. One of the biggest issues with multiple heads on at the same time is people are tempted to take a longer shower...that can deplete your water heater in a surprisingly short time.

Delta's R10000 rough-in valve will work with numerous trims. If you want to ensure the maximum volume on a Delta valve, choose their thermostatically controlled trim and cartridge. Costs a bit more, but their specs say it can flow more than the more common, single handle pressure balanced valve they sell that will fit into that same rough-in valve body. While a big box store may sell all the parts in one kit, at a pro shop, the rough-in valve is sold separately from the trim which contains the cartridge you need to make it all work.

 

[Ryan98270]

Thank you for the response. I found the R22000 rough in valve which appears to be integrated and have the ability to do what im looking for... I guess the rainshower doesnt need a lot of pressure, I ordered a showerhead designed to mimic rain, not a full body spray. I was hoping to confirm my plumbing plans were solid though... Ive drawn this up - the yellow at the top is indicating pex running through attic. I also planned on using a stainless pipe for the wall shower head, not pex... Do I need 90 deg elbows at all the bends or do I preserve pressure by using those slow radius bending guides they make for pex?

 

[Jadnashua]

Personally, I'd continue the copper up to the valve, but pex will probably work. Water flows faster through it, but it does have a smaller ID. Using copper also makes it easier to anchor your valve in place.

I'm a fan of avoiding extraneous parts. In this case, avoiding unnecessary extra fittings on the pex run(s). It's also cheaper. Use a bend support if you need a sharper bend, but it works just fine if you can accept a larger radius bend without. The hassle you might have with anything in the attic is freezing, and the line, especially with pex, may not drain when you shut the valve off. Think finger over the end of a straw. Plus, the tubing might end up outside of the insulation. Ideally, it will be run underneath and that will also protect it from any UV that might sneak in through any attic vents.

Expect a burst of potentially cold water when you turn on the rainshower head...and, it might drip for awhile after you shut the water off.

 

[Bannerman]

it might drip for a while after you shut the water off.

I've talked with people that were not at all pleased hearing water continue to drip for hours after the rainfall head was last used. To anticipate this and attempt to prevent it from occurring, you may wish to consider the following:

• Install a tub spout nearby to the shower stall floor. Not only will it be handy for obtaining water when cleaning the shower stall, but it will also allow water within the pipes feeding the showerhead(s) to drain back which will cause air to be drawn through the showerheads which will reduce the amount of water remaining to cause ongoing dripping from the heads.
• Instead of installing a level horizontal pipe in the ceiling, allow a slight slope backwards to assist the water within that horizontal section to drain back to the tub spout at the conclusion of each shower.
• Use the minimum length of drop pipe between the ceiling and the rainfall head. Even when there is drain back to a tub spout, a substantial quantity of water contained in that vertical drop pipe will continue to remain and flow into the rain head resulting in dripping. One method to reduce the drop pipe length will be to lower the ceiling above the shower stall. The lower ceiling section will be below the attic insulation so the pipe will not be exposed to cold attic temperatures.

With regard to pressure, the pressure at one shower head will be reduced by half if a second identical shower head is also operated at the same time. Both will be forced to share the pressure that had been available to only one. Since a rainfall head will likely have a higher flow requirement compared to a standard showerhead, in utilizing both at the same time, you may find neither may provide the flow and pressure you wish or anticipate.

To anticipate that possibility, you may wish to consider increasing the diameter of the hot and cold pipes feeding a shower control designed to supply multiple showerheads.

 

[Ryan98270]

Can I get some opinions on this soldered joint? It doesnt have a liquidy beed like my others, but its holding water for several hours now. Im just not confident in how it looks. I used tinning flux and a 1/2 inch solder. Am i fine to close the wall up if no issues for a couple days? If not, can I just do a touch up to it somehow? If so does turning the house water off empty the pipe on the floor above, or can it be touched up with water on?
Thank you!

 

[Ryan98270]

Also, I did use copper everywhere except the overhead faucet. I got away with using a single elbow joint in that entire run, and ill be sure to insulate the 2 feet of pex in the attic. Its already sitting below the blown insulation on top of the sheetrock. Thanks for all the suggestions

 

[Jadnashua]

FWIW, actual water pressure will change because of elevation changes (0.43#/foot) and friction during flow, but other than that, the actual pressure will be the same regardless. What makes shower head 'feel' good is when the restriction is large enough to introduce the Bernoulli effect...functionally, the water is backed up by a restriction, so it accelerates through the restriction trying to maintain the original volume flow. Because higher velocities in the pipe create more friction, at some point, the velocity will drop. The actual water pressure is the same, though. The only time the water accelerates is if there's enough volume that then creates that restriction. The pressure in say a soaker hose is the same as that going into a spray head...it's just that there's less restrictions, so the water doesn't accelerate through the openings like it would in a nozzle/jet.

A typical 1/2" shower valve will flow somewhere between 5-6gpm on average. A showerhead in the USA is limited to a maximum of 2.5gpm. So, with two going at the same time, you may not get the backup, and thus the acceleration through the jets, so the velocity of the water coming out may not go up, so it'd be more like it was just flowing through the pipe at the sink. A thermostatically controlled valve tends to flow at a higher rate than a conventional pressure balanced single handle valve. A rain head might be 2-3' higher up than one mounted on the wall, so yes, if you capped it and put a gauge on it, just that would read a slight pressure reduction. But, a rain head will have lots of outlets, so there will be no backup or restriction, and the water will just flow out like the pipe was not capped with a head at all...IOW, the velocity won't increase.

Once you get the concept of pressure and volume, it makes more sense. A fire hose will have the same pressure as that of a 1/4" line fed from the same source, but the fire hose will have lots more volume. In a multi-head shower, volume is required. that may mean larger pipes and valves all the way back to the source to function well. Now, raising the source pressure will change things at the outlet, too, but there are limits. One is if you exceed the design parameters of the pipe in question, you can create turbulence, noise, and literally wear the pipe out from the inside. Copper Institute says to not exceed 5fps with hot water in a copper pipe. That equates to 4gpm. Given that you normally mix some cold with your shower water, getting 5gpm with a 1/2" pipe is reasonable. A 3/4" pipe at the same velocity can source 8gpm (the r-squared factor in the opening area).