Water pressure
Koontz - Jen, the reader in southern California, wrote regarding concerns over the water pressure at her remodeling project because she wants to install multiple shower heads in her master bath shower. The sales person for the new shower valve recommends a 3/4" water supply line, the GC on the job informed Jen that her house has a 3/4" supply, but he expects to bring it down to 1/2" to supply the shower.
Jen readily admits that she doesn't know what changing the main water line would entail, and I'm guessing that if she asked her GC about doing this, his heretofore adaptability might be strained a bit. Changing out a main supply in a remodel is fairly complex, very expensive and hopefully, for this project, unneeded.
The main supply is first dependent on the supply size and pressure you receive from your municipality. If they come into your meter with a 3/4" line, changing your house supply to 1", or 1 1/4" as Jen mentioned, is no help.
You can think of the water main in your house like the blood lines in your body. The line starts somewhere (from the municipality) and here it is at it's largest diameter- (my analogy would be your heart). As the line moves through your house, it is sized down appropriate to the fixtures it is supplying. Maximum pressure is related to volume, so as the pipes narrow down, the volume is decreased, therefore the pressure reduces. This is unnoticeable to us in our homes when we are opening up one shower valve, but you put four shower valves in, turn them all on at once, and these sizing differences might create a dramatic difference in how much water flows from each shower head.
Here's a good experiment to see how those four valves might function on your existing system. Open up four separate water valves in the house (or put a 4-way splitter on an outside hose bib and open up all of them), and then check out the pressure. This will be comparable to the shower with all four valves opened up. You can also call your local water board and actually ask them what the pressure is at the main line and then call the manufacturer of your shower system and compare the ratings, but the first experiment is the "quick and dirty" option.
If the pressure is too low Jen, ask your Contractor to keep the 3/4" line all the way to the fixtures-he can do this without replacing the entire main line. He'll pull out the intersecting 1/2" off-shoots to the shower that now exist and run 3/4" pipe or flexible water line in it's place. You won't want to be running the dishwasher when you shower, but at least you can utilize the new system properly.
Jen readily admits that she doesn't know what changing the main water line would entail, and I'm guessing that if she asked her GC about doing this, his heretofore adaptability might be strained a bit. Changing out a main supply in a remodel is fairly complex, very expensive and hopefully, for this project, unneeded.
The main supply is first dependent on the supply size and pressure you receive from your municipality. If they come into your meter with a 3/4" line, changing your house supply to 1", or 1 1/4" as Jen mentioned, is no help.
You can think of the water main in your house like the blood lines in your body. The line starts somewhere (from the municipality) and here it is at it's largest diameter- (my analogy would be your heart). As the line moves through your house, it is sized down appropriate to the fixtures it is supplying. Maximum pressure is related to volume, so as the pipes narrow down, the volume is decreased, therefore the pressure reduces. This is unnoticeable to us in our homes when we are opening up one shower valve, but you put four shower valves in, turn them all on at once, and these sizing differences might create a dramatic difference in how much water flows from each shower head.
Here's a good experiment to see how those four valves might function on your existing system. Open up four separate water valves in the house (or put a 4-way splitter on an outside hose bib and open up all of them), and then check out the pressure. This will be comparable to the shower with all four valves opened up. You can also call your local water board and actually ask them what the pressure is at the main line and then call the manufacturer of your shower system and compare the ratings, but the first experiment is the "quick and dirty" option.
If the pressure is too low Jen, ask your Contractor to keep the 3/4" line all the way to the fixtures-he can do this without replacing the entire main line. He'll pull out the intersecting 1/2" off-shoots to the shower that now exist and run 3/4" pipe or flexible water line in it's place. You won't want to be running the dishwasher when you shower, but at least you can utilize the new system properly.
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