1/2" Supply Line

I was in a home today and noticed it was running a 1/2" copper supply line right from the meter it did have a 3/4" main from the street. It ran to the water heater both in and out as a 1/2" line and to all fixtures. This house was built in 1944 and is only 720 sq ft single story with a basement and has one bath and a kitchen and laundry hookup. The house had galvinized piping in some areas which was original to the home but my concern is it a problem to run a 1/2" supply line from the meter to the hot water tank then to the fixtures I dont recall seeing this before I thought you needed a 3/4" supply to the hot water bot in and out then 1/2" supply branched off and ran to fixtures. This is in Ohio and my concern is did a homeowner take it upon himself to size the line 1/2" or is this a possible code violation that needs to be checked out.

Since it’s a 3/4" supply and not a 1" I believe the 1/2" pipe is fine since you want the branch lines to be smaller than the supply.

Harry probably removed the old galvanized pipe, saw it was only 1/4" ID, and figured he’d upgrade to 1/2". :|.)

In my area, in 1940’s homes, I typically I see:
1" service,
3/4" supply,
1/2" to fixtures.

If there is any galvanized pipe still active that would be my concern.

720 sf!!!

I don’t think they will be running out of water in that house!

Code violation?! I don’t think there is an AHJ in Dayton that was working in 1944 that you could ask.

How about sticking to the HI Standards of Practice and test for functional flow and drainage and leave it at that?

What size feeder tubes are at plumbing fixtures in all houses? 3/8"?
I don’t think you have to worry about 1/2 copper.

Also for some added information, a seller is not required to “upgrade” anything in a house being sold. They are only required to repair it if it is broken or disclose that it is busted.

It is done that way so that water systems have balanced hot and cold water pressure.

This means that the water supply which is cold goes solo to the hot water heater tank and from the water heater tank, you have hot and cold piping next to each other on their way to supply fixtures.

The exception is the tankless system which needs only a cold supply.:slight_smile:

Minimum is 3/4" today, but I wouldn’t call it out on that small home unless there was a problem with functional flow.

Char had a store years ago and the only pipe between the home and store was a one inch .
I put phone, Intercome, and tv cable, and a 1/4 plastic water pipe in it .
In the store I put in a 10 gallon Bladder storage tank .
We ran that for years and never was short of water .
Had a wash room and toilet two sinks and small water heater .
If I had run short of water I would have put in a second Bladder tank

Call out the galvanized pipe. Test for functional flow. If there’s not enough pressure, call it out. If there is enough pressure, then 1/2" would seem to be sufficient for the size of the home.