Water line to garage

[fairway605]

Going to run pex in a 4 inch pipe I buried under the slab of the breezeway and garage from the crawl space of the house. House plumbing is 1/2 in galvanized should I stay with 1/2 in or go with 3/4 pex , run will be about 40 feet hot and cold.

 

[sberry]

3/4 cold 1/2 hot.

 

[NUTTSGT]

Even though I have no experience with PEX, I'd vote for the PEX rather than the galvanized. The latter will have a joint every 10 feet and the PEX, just one at each end.

 

[Farmall450]

Pex all the way.

 

[mrobins297aaa]

3/4 for hot and cold, I'm sure someone will correct me if I'm wrong but I believe the inside diameter of 3/4" pex fittings is about 1/2"

 

[rburke65]

Not much cost difference so I'd run 3/4" for both.

 

[ard]

any thoughts about a hot water return, to allow a recirc system?

 

[Bob275]

Galvanized pipe for drinking water? I'd change it ALL to 3/4 pex...

 

[mrobins297aaa]

another idea is to run 1 cold water line and use a instant water heater in the garage to get hot water.
especially if your a long way from the hot water tank

 

[roc_on_the_rocks]

another idea is to run 1 cold water line and use a instant water heater in the garage to get hot water.
especially if your a long way from the hot water tank

That's a good idea I might use someday.

 

[coljar]

another idea is to run 1 cold water line and use a instant water heater in the garage to get hot water.
especially if your a long way from the hot water tank

That is what I done in my garage, but the instant hot water heater is fed from the house hot water line. My lines are in conduit from the house. The hot water line is 1/2" pex and the cold water line is 3/4" pex.

 

[mrobins297aaa]

That's a good idea I might use someday.

I'm just running my instant water heater off of a 20# barbq tank

 

[csp]

OP stated that pex is to be used on the run to the garage and that the existing in the house is galvanized.

 

[JonBoehman]

I run just at 200' of 3/4" pex from my house to the shop in one piece. The did both hot and cold in 3/4" with no issues. The pex tools are worth the money due to the simplicity, durability and proficiency of the pex systems

 

[James-W]

Another vote for just running one cold water line putting a water heater of some sort in the garage. Can be tankless or a regular tank type water heater. Either way would work OK, but I think for this application the tankless type would be best suited. That is, unless you use an awful lot of hot water in the garage.

 

[CNGsaves]

I like what Sberry Coljar have listed above . . . . 3/4 Pex cold & 1/2 Pex hot along with the Point-of-Use Hot Water Heater in garage.

Only variation that might change this . . . . HOUSE has oversize TANKLESS Heater that could provide endless hot water to the garage. THIS is my long-term ultimate solution. With this, I'd rethink and size lines as big as necessary to provide maximum flow at farthest spigot. Having endless hot water to wash vehicles on concrete slab outside garage is my long-term goal. No need for a Hotsy power washer when any old power washer becomes VERY nice when it's pouring out HOT water !!

 

[fairway605]

Thanks for the ideas, definitely things I didn't think of.

 

[OccupantRJ]

I went with a 3/4" cold water line to the shop and have a microwave next to the sink if I want a bit of hot water to add in the sink, or want to make a hot drink.

 

[yeldogt]

If you are just feeding a sink and single hose outlet -- 1/2 pex is fine for both. 40' is not all that long. I would only use 1/2 for the hot and try and get some insulation on it -- 3/4 holds a lot of water and you will wait for the hot on a line underground.

I have 1/2 in my garage w/o any issues (washing cars etc.) -- I do have a 3/4 line to my pool for max speed when I need to add water.

 

[Bretny]

another idea is to run 1 cold water line and use a instant water heater in the garage to get hot water.
especially if your a long way from the hot water tank

This!
Those point of use water heaters are cheap. 40ft of underground hot water pipe might take 5min to get any real heat in the water. It has to heat the pipe then what its touches first.

 

[like2wheel]

I'm sure 1/2" would have been plenty for my needs, but when I noticed how much thicker the wall was on 3/4" I went with that.

 

[dw1]

I ended up running 1" black poly- water line into my barn, from there I ran 1/2" Pex over into my bath room/shop sink. I have an "On Demand" water heater in my bathroom feeding my shower and wash tub, it works pretty good.

 

[James-W]

I ended up running 1" black poly- water line into my barn, from there I ran 1/2" Pex over into my bath room/shop sink. I have an "On Demand" water heater in my bathroom feeding my shower and wash tub, it works pretty good.

Running the 1 inch line is a good idea since you are branching off 2 lines each 1/2 inch for the hot and cold water.

 

[NUTTSGT]

another idea is to run 1 cold water line and use a instant water heater in the garage to get hot water.
especially if your a long way from the hot water tank

I had thought about suggesting that but the OP seemed maybe intent on running a dedicated hot water line to the garage.

I'm just running my instant water heater off of a 20# barbq tank

Mind posting what model you are using and how well it's working ? I have one water line to the garage and have considered this myself a few times.

 

[henrysgarage]

You could use an RV hot water heater, 110 and/ or propane.

 

[johnnyradiant]

Most taps are restricted below 3/8". To move hot water down a long run to a faucet takes awhile to flush out all the cold water. Upsizing to 3/4" only takes more water and longer to get the water to the tap. As tempting as it is I'd stay at 1/2" for the hot IF I was going to run two lines. If I were to run a recirc (not unless there was a residence above the shop) I'd run the hot and recirc lines as 3/4" with two ball valves on the recirc line - one for the stop and one as a valve to throttle back some of the flow. I would be more than likely to run one line to the shop and put in a little hot water tank or a little tankless unit.

 

[ard]

Most taps are restricted below 3/8". To move hot water down a long run to a faucet takes awhile to flush out all the cold water. Upsizing to 3/4" only takes more water and longer to get the water to the tap. As tempting as it is I'd stay at 1/2" for the hot IF I was going to run two lines. If I were to run a recirc (not unless there was a residence above the shop) I'd run the hot and recirc lines as 3/4" with two ball valves on the recirc line - one for the stop and one as a valve to throttle back some of the flow. I would be more than likely to run one line to the shop and put in a little hot water tank or a little tankless unit.

What about a hot supply at 3/4" and the recirc return at say 1/2"?

Agree with the assessments on need, but assuming you did do a recirc.....

 

[johnnyradiant]

What about a hot supply at 3/4" and the recirc return at say 1/2"?

Agree with the assessments on need, but assuming you did do a recirc.....

You could certainly do 1/2" return, it would be more than needed but I would likely do 3/4" because it is just that much less water chugging along the line. It comes from my experience with copper recirc lines. Though they may spec out to be size X they inevitably wear thin faster than if they had been sized X+1.

 

[The Cobbler]

I would do 3/4 cold and forget the hot. put a water heater in the shop . 40' is a long run (especially underground) to get hot water

 

[mrobins297aaa]

Mind posting what model you are using and how well it's working ? I have one water line to the garage and have considered this myself a few times.[/QUOTE]

It's a ecco temp FVI 12.
I've had it maybe 5 years, I bought it off ebay for maybe $250.
Like I said before I'm running it off of a 20# barbq tank.
I purchased one of those lp regulators from homedepot for a barbq and have been using that to connect between the tank and the water heater. Those regulators are good for about 75K BTU's and I think that is what the heater is.

One tank lasted me all summer this year, that being said I don't use it that much so it's relative.

I've been using it for washing my hands, washing the vehicles and even power washing the underside of my cars.
It has worked fine but it suffers from the same thing that all the cheaper point of use water heaters do, it won't come on if you have very little flow, so to get around this I usually have the temp set to around 90-100 deg and then just use the hot water tap only.

I don't use it in the winter so I drain it.

Make sure you put in some valves and hose bibs so you can isolate it and flush it out with vinegar every so often..........it's nice to have those hose bibs just below the heater for filling mop buckets with hot water and even hooking a hose up to a power washer.

 

[roc_on_the_rocks]

Mind posting what model you are using and how well it's working ? I have one water line to the garage and have considered this myself a few times.

It's a ECCO TEMP FVI 12.
I've had it maybe 5 years, I bought it off ebay for maybe $250.
Like I said before I'm running it off of a 20# barbq tank.
I purchased one of those lp regulators from homedepot for a barbq and have been using that to connect between the tank and the water heater. Those regulators are good for about 75K BTU's and I think that is what the heater is.

One tank lasted me all summer this year, that being said I don't use it that much so it's relative.

I've been using it for washing my hands, washing the vehicles and even power washing the underside of my cars.
It has worked fine but it suffers from the same thing that all the cheaper point of use water heaters do, it won't come on if you have very little flow, so to get around this I usually have the temp set to around 90-100 deg and then just use the hot water tap only.

I don't use it in the winter so I drain it.

Make sure you put in some valves and hose bibs so you can isolate it and flush it out with vinegar every so often..........it's nice to have those hose bibs just below the heater for filling mop buckets with hot water and even hooking a hose up to a power washer.

Just for my learning, wouldn't an electric heater make more sense than propane tank?

 

[NUTTSGT]

It's a ecco temp FVI 12.
I've had it maybe 5 years, I bought it off ebay for maybe $250.
Like I said before I'm running it off of a 20# barbq tank.
I purchased one of those lp regulators from homedepot for a barbq and have been using that to connect between the tank and the water heater. Those regulators are good for about 75K BTU's and I think that is what the heater is.

One tank lasted me all summer this year, that being said I don't use it that much so it's relative. ......

Thanks and that was something I wondered about, a vent for it.

 

[mrobins297aaa]

Thanks and that was something I wondered about, a vent for it.

the thru the wall vent was included with the heater.

 

[mrobins297aaa]

Just for my learning, wouldn't an electric heater make more sense than propane tank?

yes you could use electric heater the problem is to get the same 75000 BTU's you need over a 100 amp circuit just to run the heater...........those electric instant water heaters use a huge amount of electricity

 

[roc_on_the_rocks]

yes you could use electric heater the problem is to get the same 75000 BTU's you need over a 100 amp circuit just to run the heater...........those electric instant water heaters use a huge amount of electricity

Got it, thank you.

 

[ct03911]

I ran one 3/4 cold pex to my garage and have a 40gal electric hot water heater mounted up on the wall.
I wash a lot of cars and there is future apartment space over the garage so I went with good capacity.
FYI I dialed the water heater back to 120 degrees. I saw most pressure washers or hoses were rated to 120. Anyways, plenty of hot water for me and it’s available within 15 minutes it seems once I turn on the tank heater.

(Another pix rotated by GJ from an IPhone)

 

[amkluttz]

No need for a Hotsy power washer when any old power washer becomes VERY nice when it's pouring out HOT water !!

Just be careful with this. Most pressure washers, especially electric versions, are not rated for hot water. I believe the cold water is used to cool the pump.

 

[OccupantRJ]

I ran one 3/4 cold pex to my garage and have a 40gal electric hot water heater mounted up on the wall.
I wash a lot of cars and there is future apartment space over the garage so I went with good capacity.
FYI I dialed the water heater back to 120 degrees. I saw most pressure washers or hoses were rated to 120. Anyways, plenty of hot water for me and it’s available within 15 minutes it seems once I turn on the tank heater.

(Another pix rotated by GJ from an IPhone)

I found that if I take pictures I plan to post in landscape mode I don't end up with sideways pics.

 

[justinthurn]

be careful with hot water on any old power washer. I have ruined a few in my day. hot water eats the seals almost instantly. I ran 1" poly for the main from the house to the shop, then pex from there. on demand or tank water heater are both fine, just make sure you size them to what you will actually be running.

 

[The Cobbler]

be careful with hot water on any old power washer. I have ruined a few in my day. hot water eats the seals almost instantly. ....

pressure washers aren't meant to pump hot water, the hot units pressurize the cold water & pump it through the heater .