Water main size?

[Tcfab]

I’m building a shop that is 500’ of the main road where my water meter is. The water meter is 3/4”, my length of pipe is going to be about 500’~550’. There is only going to be a single bathroom in the shop with 3 hose bib’s for the occasional washing down the floor for cleaning. I was told 1” water line would be more then enough from the local supply house, but i’m questioning if I shouldn’t do 1.25 or even 1.5”? What’s your thoughts? Thanks

 

[Breplum]

You should state what the static water pressure is.

 

[Sponsor]

 

[John Gayewski]

Length of pipe is only one factor in determining pipe size. You need the elevation change and, as stated above the static pressure, since you've already listed the fixtures being served.

 

[Tcfab]

Length of pipe is only one factor in determining pipe size. You need the elevation change and, as stated above the static pressure, since you've already listed the fixtures being served.

Okay, I’ll try and get a pressure gauge on it. Very little if any elevation change, wouldn’t be more then 12”, pretty flat farm ground.

 

[Reach4]

Pipeline Pressure Loss Calculators (wsu.edu)

I put 600 ft, 10 gpm, 5 psi loss, it said use 1.3 inch or bigger.

A bathroom without a tub would take under 5 gpm. I chose 10 for some margin. Pressure washers don't take 5 gpm usually. But still, you might want more flow at some point.

On the other hand, bigger pipe does not cost that much more. I would use 160 psi polyethylene. Do not pull the pipe tight, but rather snake it in the trench for thermal contraction reasons. I am not a pro.

While you are not in Menard's area, this shows that 500 and 600 ft rolls 0f 1.25 are available.
Is your supply house suggesting using barbs with SIDR pipe, or compression fittings that are popular with water service it seems? Different size pipe for that. For barbs, there is a standard inside diameter for the pipe.

1-1/4" SIDR 9 200 PSI Excel Potable Water Poly Pipe at Menards®