Robert A.
New Member
I have 3/4" copper supply to the house with 1/2" branches to two bathrooms & the kitchen. A new shower fixture has 3/4" inlets. What kind of trouble, if any, would I be in for if I adapt the 1/2" supplies to this 3/4" fixture?
3/4" main supply, 1/2" pipe to bathroom, but fixture is 3/4"
- Thread starter Robert A.
- Start date
Users who are viewing this thread
It depends on how much output you need. The Hansgrohe I-Box has 3/4" inputs, but if you're just running a shower head and tub spout, then 1/2" is fine.
Sponsor
Paid Advertisement
Jadnashua
Retired Defense Industry Engineer xxx
1/2" copper in hot should not be asked to supply more than 4gpm. When you add in some cold to temper the hot, most 1/2" valves are limited to about 6gpm, but a 3/4" one typically can supply nearly twice as much if you need it when supplied by 3/4" lines.
I've seen this situation arise a few times where the fixture is larger than the stub out from the wall. In this case, it appears that the fixture is 3/4", but the stub out is only 1/2".
Which begs the question... Wouldn't it be prudent to just stub everything out to 3/4" in new construction for everything? You could always drop down to 1/2" or whatever after the stub out. This way you are sort of future proofing the construction so that if advances in fixtures in later years require a larger supply, such as in this case, then you would still be ok. What do you guys think about just doing rough-in for everything stubbed out to 3/4"?
Which begs the question... Wouldn't it be prudent to just stub everything out to 3/4" in new construction for everything? You could always drop down to 1/2" or whatever after the stub out. This way you are sort of future proofing the construction so that if advances in fixtures in later years require a larger supply, such as in this case, then you would still be ok. What do you guys think about just doing rough-in for everything stubbed out to 3/4"?
I am not a pro. I think that would not be a good idea for hot water stub-outs, particularly for a lavatory, because 3/4 is about double the volume for a given length. Thus you would wait twice as long for hot water, and you would put twice as much water down the drain before the hot arrives.
Jadnashua
Retired Defense Industry Engineer xxx
It could make sense on potential high volume points of use, but otherwise, it's probably an unnecessary expense, and as said above, it will take longer to purge the room temp water out of the hot line before you get hot there unless you have a recirculation system. A common recommendation would be to run 3/4" to the bathroom group, then branch off. Depending on the layout, it might make tapping the 3/4" line fairly simple if you needed higher volume.
Rdura
New Member
My plumber left me a 3/4 inch stub 0ut for the shower head. Am I correct in thinking most shower heads and arms are 1/2 inch, and therefore, I should be looking to purchase a 1/2 shower arm and a 1/2 female to 3/4 male brass fitting.
Jeff H Young
In the Trades
most shower heads and tub spouts? I'd say around 99.9 percent are 1/2" don't know exactly what you got going on but 3/4 is for higher flow.
Rdura
New Member
I think I goofed in thinking the threaded stub is 3/4, the outside diameter exceeded .75 so I incorrectly assumed it's 3/4.
Rdura
New Member
I have an external shower plumbed, the only thing missing is the shower arm and shower head. I will be using oiled bronze hansgrohe valve trim. My goal is to make the arm and head look old/weathered as my area is rustic, the architecture is rustic, and I don't want something shiny/interior-ish to stand out like a sore thumb. I'd rather have the shower not catch the eye - the arm/head will be the only visible component, as the valve trim and outdoor "pan" are obscured by four foot shrubs. I won't use a drain as there is plenty of room for the water to run off and it will benefit the foliage. I'm seeking suggestions for the arm/head. One thought is PVC, and paint it the same color as the structure's stucco wall. Another is brass, another is copper, which I think would patina nicely outdoors. Of course all of these are straight pipes, and I need an angle to direct the shower head flow. Would 3/4 copper with a 1/2 inch threaded fitting on each end work? On the shower head end of the pipe I could solder in a 45 degree fitting. As for the shower head, perhaps an inexpensive plastic one, painted the same color as the stucco? I can always replace it if it does not weather well outdoors.
Jeff H Young
In the Trades
why not buy a arm and flange color of choice
Rdura
New Member
A good opti0n ... it seems that some of oiled bronze or black items are pricey.
Jeff H Young
In the Trades
11.98 sounds reasonable . but you could paint something up maybe you want a more industrial look for out doors
