Irrigation stub out for future?

[Mikha'el]

As part of my complete tear out/rebuild I thought I'd be kind to a future owner and stub out a 1" line to the exterior for a future irrigation system.
But poking around at irrigation design sites, it looks like the contractor often just locates the incoming service out in the yard and taps in.

Is that the norm? If so I'll save myself the bother.

Thanks,
Michael

 

[Breplum]

For the front yard, yes the incoming service is typically where a tee would be located.
For the rear, definitely stub out. 3/4" is fairly normal, but depends on what kind of system is expected, and so, sized accordingly.

 

[Sponsor]

 

[Mikha'el]

For the front yard, yes the incoming service is typically where a tee would be located.
For the rear, definitely stub out. 3/4" is fairly normal, but depends on what kind of system is expected, and so, sized accordingly.

Thanks for the reply.

The spot I'd stub to is sort of on the wrong side of the house/driveway anyway.
Will probably just stub a 1" outside the utility service room - just in case - while I have it opened up.

 

[Reach4]

As part of my complete tear out/rebuild I thought I'd be kind to a future owner and stub out a 1" line to the exterior for a future irrigation system.

Remember that irrigation water should not go through a water softener. While planning, you might consider a softener or other water treatment -- even if it is just a cartridge filter.

 

[Mikha'el]

Remember that irrigation water should not go through a water softener. While planning, you might consider a softener or other water treatment -- even if it is just a cartridge filter.

Yes, irrigation & hose bibs will tee off ahead of the softener.

 

[WorthFlorida]

Where you decide to stub out for the 1" future irrigation feed, you want to tee off a 1" supply. If it is 3/4 inch in your utility room to stub out with 1", it is OK but just realized that you're not getting any more water than a 3/4" line can supply. Most irrigation valves start at 1" anyway. Running 1" pipe underground and then tee off to 3/4" or 1/2" for sprinklers will allow less water pressure lost on long runs.

Do try to tee off before the water enters the home. It is very common that the water line has to be run under the driveway. But for irrigation all you need is power for the controller which is usually easy to do and with WiFi controllers, its location is not so critical.

 

[wwhitney]

If it is 3/4 inch in your utility room to stub out with 1", it is OK but just realize that you're not getting any more water than a 3/4" line can supply.

That's not quite right, a short segment of 3/4" in a long run of 1" doesn't throttle your output as much as doing the whole run in 3/4" would. There's an approximate conversion factor from 3/4" to 1" pipe, i.e. each foot of 3/4" pipe in the run will be equivalent to X feet of 1" pipe. The empirical Hazen Williams formula say X = (d1/d2)^4.87, where d1 and d2 are the internal diameters (assuming the same type of pipe).

Cheers, Wayne

 

[Mikha'el]

That's not quite right, a short segment of 3/4" in a long run of 1" doesn't throttle your output as much as doing the whole run in 3/4" would. There's an approximate conversion factor from 3/4" to 1" pipe, i.e. each foot of 3/4" pipe in the run will be equivalent to X feet of 1" pipe. The empirical Hazen Williams formula say X = (d1/d2)^4.87, where d1 and d2 are the internal diameters (assuming the same type of pipe).

Stands to reason... but all that to say - there is no 3/4" involved, it's 1" copper all the way to the manifold, with a tee ahead of the softener bypass.

My current thought (and this one might stick) is to DIY a little 1" copper x PEX manifold and run 3/4" PEX to the hose bibs on the meter side of the driveway and 1" to the other side - for future irrigation for the backyard and/or small front side yard.

Thanks, gentlemen.

 

[wwhitney]

FWIW, the same analysis applies to 1" copper vs 1" PEX. I think for new copper runs, the smoothness factor is the same as PEX, so you can again just look at the ratio of inner diameters, to the 4.87 power.

Cheers, Wayne