I just bought all the new water and gas pipes and will be getting a new sewer in a few days.

I'm using galv 3/4 and running the hot with a foam wrap around and putting it inside a PVC pipe to help keep the heat in. We really don't get freezing pipes here (Sacramento) so I'll leave the cold bare.

Here's the question: I know the gas need the extra expensive yellow tape to seal the threads, but what about the threads on the water pipes? Can I use just regular teflon tape or should I go buy some pipe dope?

Most of it will be under the foundation so I don't want to do it twice.

Thanks, KarlJay.

 

Pipe dope, no question about it. Make sure to install the whole system, cap, and pressure test before pouring on top of it. Otherwise, in a couple years you might find a problem when part of the slab falls into a sinkhole.

 

Yep, what Ford-six said, but why are you using galvanized? Copper or PEX are much better alternatives these days. Especially underground

 

I'm using gal because that's what was there, didn't know about PEX. I've already got it laid out, so probably too late to change over...

 

being in cali, there might be some sorta of wacky earthquake codes, might want to check into it before you start installing.

 

Consider PEX - I started using it in the house we are currently renovating, and love it. Approved for burial and under concrete. Consider this also - the pipe itself is cheap enough that where the pipe will be inaccessible after installation (such as under concrete), you can make two runs separated as far as possible but
starting and terminating near each other. Cap one, use the other. If for whatever reason the one in use is damaged, you have a backup.

Some people are starting to use it for shop air distribution, as it doesn't shatter like pvc, and is good up to 130 or 140 PSI, and a heck of a lot quicker, easier, and cheaper to run than copper. Just don't subject it to high heat!

I am running underground about 60 feet from house to garage for electrical service, and plan to drop 2 runs of 1/2" pex below the electrical. One for telephone, and one spare, There already is water to the garage, but if it gives trouble, I have a backup, and don't intend to dig it twice! Food for thought.....

Oh yeah, one drawback is pex can't be exposed to sunlight.

 

Gal for gas is a no-no, black iron. Some reaction between the gas/odorizor and the gal--but I tried to find something on this, and it seems a bit sketchy. However, it is commonly said not to use gal for gas, and code may come into this also.

Now, the plumber I used on our garage said:

--no joints in the concrete. Don't know how you get around it, but it makes sense in a way to me....

--he also said he never puts water pipes in the slab anymore. He would do it if I wanted, but said it's trouble waiting.

So, I used some 4" and 2" ABS in the slab to make a sleeve to bring my water in underground, then bring it up in the building.

Theoretically, it's all accessable, at least to inspect....

Gal for water? I have what must be at least 40, maybe 50 year old gal sprinkler pipes. Look like heck on the outside. Inside, they are clean, clear and full diameter. I know stuff builds up sometimes in gal, but I can't prove it from those pipes.

It might pay to recheck code on the gas and joint thing.....

Good luck on your project.

 

Problem with galvanized for gas is the galvanizing eventually flakes off and starts plugging things up in the gas valves and nozzles, etc. Copper for gas, or black iron. There is a plastic sheathed copper available for underground, where codes permit it.

 

California won't allow copper for gas. The gas here has H2S init and it attacks copper and will disolve it. Black Iron or plastic

 

i used PEX when i constructed a new bath in my house. That stuff is great. And at $26.00 for 100 feet, you can not beat the price. Easy to cut and install.

 

I should clear this up a bit, I'm using Galv for water and black pipe for the gas and ABS for the sewer.

Good news, this weekend I've figured out how to re-route the sewer, so I should be ready to pour in about 2 days.