PEX sizing - new hose bibs

[Mikha'el]

(also posted in irrigation forum)

G'day all,

Existing plumbing is all in-slab copper - 1" incoming service, 1/2" tee ahead of softener loop feeding two hose bibs. I'll be running PEX to new hose bibs at each corner, from a 1" manifold of some sort.

Any suggestions on PEX sizing, individual homeruns vs. trunk/branch, etc? We're on city water, no idea on the pressure.
The old 1/2" copper has been adequate for our use, though could probably use an upgrade for future irrigation.

Thanks for the help,
Michael

 

[Reach4]

Existing plumbing is all in-slab copper - 1" incoming service, 1/2" tee ahead of softener loop feeding two hose bibs. I'll be running PEX to new hose bibs at each corner, from a 1" manifold of some sort.

Any suggestions on PEX sizing, individual homeruns vs. trunk/branch, etc? We're on city water, no idea on the pressure.
The old 1/2" copper has been adequate for our use, though could probably use an upgrade for future irrigation.

3/4 or 1 inch to the softener and water heater. Maybe 1 inch into the tee which feeds the WH, and then down to 3/4.

Split off the lines to the hose bibs before the softener. Run that line into the tee with 1 inch. Consider a whole house cartridge water filter after the tee to the hose bibs. You may want to consider a soft water line to near the driveway for car cleaning if you ever do that in the driveway. Do not water plants with softened water.

Home-run vs branch? Branch is usually easier. 1/2 inch hot home run (or nearly home run) from the WH for a bathroom is better, because it takes less time for hot to arrive thru 1/2 than thru 3/4. Probably the same for a kitchen. 3/4 is good for cold If you will consider putting in a hot water recirculation system, to give quick hot, now is the time to think about that. Running a return line is better than systems that use the cold as a return line.

I would prefer PEX-A with expansion F1960 fittings, although the F1960 cost more than the ones you use compression rings or stainless clamps on.

 

[Sponsor]

 

[Mikha'el]

3/4 or 1 inch to the softener and water heater. Maybe 1 inch into the tee which feeds the WH, and then down to 3/4.

Split off the lines to the hose bibs before the softener. Run that line into the tee with 1 inch. Consider a whole house cartridge water filter after the tee to the hose bibs. You may want to consider a soft water line to near the driveway for car cleaning if you ever do that in the driveway. Do not water plants with softened water.

Home-run vs branch? Branch is usually easier. 1/2 inch hot home run (or nearly home run) from the WH for a bathroom is better, because it takes less time for hot to arrive thru 1/2 than thru 3/4. Probably the same for a kitchen. 3/4 is good for cold If you will consider putting in a hot water recirculation system, to give quick hot, now is the time to think about that. Running a return line is better than systems that use the cold as a return line.

I would prefer PEX-A with expansion F1960 fittings, although the F1960 cost more than the ones you use compression rings or stainless clamps on.

Thanks for the reply - sorry, I was only asking about sizing the runs to the hose bibs - for best flow/pressure.
Everything else is 1/2" home runs off a manifold, very short runs. The softener is already on a 1" bypass.

 

[Reach4]

Thanks for the reply - sorry, I was only asking about sizing the runs to the hose bibs - for best flow/pressure.

Best flow? Best is a pretty absolute word. That means 3/4, and would require special attention to the spigot.

Best practices? Normal for a house spigot is 1/2. Consider a frostless kind, which is historically not common in southern Texas, but may have suddenly become more popular.

 

[Mikha'el]

Best flow? Best is a pretty absolute word. That means 3/4, and would require special attention to the spigot.

Best practices? Normal for a house spigot is 1/2. Consider a frostless kind, which is historically not common in southern Texas, but may have suddenly become more popular.

Ha, let's replace "best" with "adequately normal..."
I was originally planning 1/2" home runs to the hose bibs off a 1" manifold, but then my usual over-think kicked in.

I didn't have any problem with frozen hose bibs, though I did cover (rockwool and a paper cup!)
There will be a shut-off valve so could drain them - for the next 30-year storm.

 

[Jeff H Young]

All things to concider that reach 4 brought up. a couple hose bibs might be ok in 1/2 a little porch to wash off and no yard to speak of. but in texas everything is big right? not knowing if its a tiny lot plus your mentioning irrigation? you might be coming off main with 1 inch you will have to evaluate but 3/4 minimum if you picking up sprinklers.
My house built in 02 2600 sq ft 2 story Pex A with home runs in attic so everything goes all the way to attic and then back down the wait for hot is horrible in my opinion running water for a few minutes or more isnt good . Im always amazed how few people install circ systems , Im alittle reluctant to add a circ system because I dont trust the pex for that plus its already done but if was repiping id be very interested. all these years ive wondered how much the operating costs are I think its pretty low but cant say

 

[Mikha'el]

All things to concider that reach 4 brought up. a couple hose bibs might be ok in 1/2 a little porch to wash off and no yard to speak of. but in texas everything is big right? not knowing if its a tiny lot plus your mentioning irrigation? you might be coming off main with 1 inch you will have to evaluate but 3/4 minimum if you picking up sprinklers.

Small lot in the 'burbs. We have some property out in the Hill Country, will likely build there after this place is done.
New owners can put in irrigation if they like, I'm ok with a hose timer and dragging out the sprinklers for now.

The way it's laid out now, all the bathrooms, laundry, kitchen are close to the manifold.

 

[Reach4]

All things to concider that reach 4 brought up. a couple hose bibs might be ok in 1/2 a little porch to wash off and no yard to speak of. but in texas everything is big right? not knowing if its a tiny lot plus your mentioning irrigation? you might be coming off main with 1 inch you will have to evaluate but 3/4 minimum if you picking up sprinklers.

Good points. There is no real disadvantages to going with 3/4 inch pex. You will probably have leftover pex anyway. I am now agreeing that 3/4 is the way to go for you.