Shower head volume and pressure for new build
kyrral
| Posted in Construction Techniques on
I love a powerfull shower with lots of water and pressure. I will be building a small house (725 sq ft) near Lake Arrow Head (but not in it, I’m not that rich) and have an open blueprint for shower design. I think the water meter starts with a 3/4″ pipe. Should I use that dimension all the way to a 3/4″ shower valve or is it better to sleeve it down to 1/2″? I plan to have 2 shower heads, 1 to squirt directly onmy lower back (kinda like dropping in the hot pool at a gym). Thoughts?
Replies
pipe
From the meter to the house, use at least 1". If this is PVC you can afford 1.25 or 1.5 if it's a long run. At the house you can go down to 3/4", but only reduce to 1/2" only for each fixture. You can get away with putting 2 toilets on 1/2 because they can fill a little slower. If you are using PEX run 1/2' from the manifold to every fixture. (Each shower head is a fixture. Put each one on its own valve.)
There are several different points of view on this. Generally, if you are doing conventional copper-style branching plumbing you'd use 3/4 in any pipe feeding more than one room, then narrow down to 1/2 with feeds for a single room. This is, more or less, minimum code requirements, and it proves satisfactory in about 90% of cases.
More "modern" flex plastic setups with "home runs" from each fixture to a "manifold" may use 3/8" pipe. This is easier to run -- just like pulling wiring -- and the individual feeds assures that there's no change in pressure at one fixture when another is used. Another advantage is that hot water arrives much more rapidly to distant fixtures.
Bear in mind that a big disadvantage of oversized feeds is the slower delivery of hot water. It takes more than twice as long to get hot water from a 3/4 inch pipe vs a 1/2 inch one.
One note about showers: It's important to have a good-quality shower valve, one that has at least basic pressure-balancing, and possibly a thermostatic element to maintain constant temperature. The valve is not the place to cut corners.
Comments on shower head pressure
Good suggestions. Another person said the pressure regulator controlled the amount of water delivery Is this something the city owns or do I? Could I adjust it myself. I'm not even sure when it would be (at the meter or in the house somewhere)/ Thanks ahead.