Considering a Future Plumbing Project.

Diggin It · Aug 18, 2018

When I moved in here and started the renovations, they had a small shower only, no tub. I put in a bigger shower stall and did a few other things. Getting to the point I may need to set and soak a bit, so I need to think about a tub. Got a lot of it thought out, but one thing is bugging me. I'm on county water and I get sufficient flow for most things, but not a whole lot. Part of it is their fault, part of it may be mine. I put a 3/4 PVC supply line from the entry point to the water heater where I split off between hot and cold. From there, it's all 1/2 PVC. Water meter and feed from there to the house are 5/8.

I'm trying to decide if I should change to 3/4 inside the house feeding the bathroom. Would there be any advantage/disadvantage with a 5/8 meter?

LS Tractor Owner · Aug 18, 2018

The difference between the 5/8 and 3/4 would be so minimal you would not notice it. What is the pressure at the meter? It should be around 50-60 PSI to be able to supply the house system. Another factor would be how far it has to travel from the meter to the house. The greater the distance, the greater the volume / pressure loss. Our water system here recommends a minimum of a 1" supply line from the meter to the house. I put in 1 1/2". The house is plumbed just like yours, 3/4" to WH split, 1/2" everywhere else. Never had any issues with pressure in the house, even if more than one tap is used at the same time. As a matter of fact, I had to have the water company turn the pressure down at the meter because I started blowing fittings. They initially had the pressure at 75. They turned it down to 60 at the meter, I have 54 at the house entrance after 200' of 1 1/2" line.

Sounds like the pressure coming into your house is low if your having issues.

EddieWalker · Aug 18, 2018

What is your water pressure? The sprinkler section at the box stores sells a meter that attaches to a water spicket that will tell you how much water pressure you have. You need to know this number before you can do anything else.

Odds are very small that you would be running multiple water lines while filling your tub. Dishwasher and laundry might be on, but neither of them use very much water and you shouldn't notice them. Sprinklers will affect your water pressure if you are watering the lawn the same time you are filling your tub.

But to just fill your tub, the water goes through a pair of valves for hot and cold that are much smaller then the half inch supply line, so making the supply line larger wont have any impact on what gets through those valves.

Diggin It · Aug 18, 2018

See, the part of it that is their problem is the pressure and supply. Main is only 4" and is a dead end line. It's not supposed to be, but it broke 5 or 6 years ago and they never fixed it; just shut the valve off at the end of the line between me and the break. Maybe some day.

The other problem is that I'm on top of a hill and their feed line comes up the hill, then back down. When they had a different break not too long ago, I lost water faster than the neighbors because it drained off my hill back towards the break.

If I remember right, the line from the meter to the house is 3/4" and it's something around 100'. I have one of those in-line pressure gauges and it usually shows around 50lbs until I open a faucet. Then it can drop to 30 lbs or less. If I flush before I go to make coffee, the sink faucet runs slow until the tank fills.

And yeah, the openings inside the faucets can be 3/8" or less.

Life in the country I guess, but at least I only pay for water and don't have a sewerage charge.

So, what I'm seeing is that there is no reason to switch to 3/4"?

thepumpguysc · Aug 18, 2018

You wanna talk about country livin?? I JUST had my WELL PUMP replaced.. its set at 30psi!! you wanna talk about a pressure drop when using the washer or toilet?? Don't even THINK about taking a shower w/ the washer or dishwasher running.. OR watering the garden..

buckeyefarmer · Aug 18, 2018

Most well pumps are 30-50 psi.

Diggin It · Aug 18, 2018

thepumpguysc said:
You wanna talk about country livin?? I JUST had my WELL PUMP replaced.. its set at 30psi!! you wanna talk about a pressure drop when using the washer or toilet?? Don't even THINK about taking a shower w/ the washer or dishwasher running.. OR watering the garden..

Well? You have a working well? You're better off than I was before the county water lines were laid. I was on a cistern that had to be filled by truck. If I forgot and let it run too low, I could be without until the truck could get here.

teejk · Aug 18, 2018

The standard around here (might be in the code) is 3/4 supply until you feed to a fixture. There is an exception I think for the toilet that can branch off a 1/2.

Gary Fowler · Aug 18, 2018

I guess I am lucky to be on a high pressure water system. I have 100-110 PSI on my outside water lines that don't have a pressure reducer on them. I had to put a pressure regulator at the house and my shop to reduce the pressure to 50 PSI for the commodes etc to handle the pressure. My meter is only 3/4 " and it handles the house and sprinkler system at the same time. It will run 11 sprinkler heads at the same time with plenty of flow for them to cover a 20 foot radius or more and still not starve the house. The sprinkler is supplied without a flow restrictor. My neighbor has about 300-400 feet of 3/4" feed line to his house and also runs a sprinkler system with no problem.

Your problem likely isn't the size of pipe, but just the low water pressure from the water company. I don't know if you could talk them into raising the pressure a bit or not.