When I had gas work done (new range installed ) I had the gas company do it. I don’t think I’d do it any other way.

Thanks, that would make sense (it's combustible material and always best to be safe!) but we are on a propane tank, and our service company just services the tank (nothing inside). Otherwise, that would be a good way to go!

It appears from the photo that he has mixed galvanized fittings and black pipe.

I'm not up on the code for propane - but natural gas is always done in black pipe or CSST in my locality.

Also, what is the thread sealer being used? It's not caulk is it?

Teflon tape for gas is yellow. It's generally a thicker tape.

Whatever thread sealer was used must be approved for propane gas - you can't wing it.

A competent plumber can do gas piping. But make sure they are doing it right.

Appreciate your thoughts, Jake The Wonderdog. For mixing the pipes, I'm wondering if he just used what was on hand. I think the galvanized pipe was existing, and he probably just reused some of it, adding the black pipe where he needed it. He is doing this work himself because he says he knows what he's doing (says he's done this work for 30 years). The gray stuff around the joints looks like caulk and not tape because it's smeared on, but I'm not sure what kind of caulk it is. I'm sure he's going to say it's ok for propane, but I would rather not just take his word for it!

We were on propane also at the time...still had their guy do the gas work for us.

Mixing black pipe with galvanized fittings is not a good idea for gas. Galvanized pipe has a coating on it that can flake off and get into appliance valves, while black pipe does not have the coating. However, some of the older pipe I've found in houses was not painted black like you see in the stores today, so what he used may have been old gas pipe.

The goop/substance you see on the pipes is usually referred to as "pipe dope" or pipe sealer. Its both a lubricant and a sealant, and is required whenever you join galvanized pipes. Its needed because iron pipe has tapered pipe threads that must be tightened down very tightly until sealed. Tip of the day - its a PIA to get off clothing, so don't get it all over you.

If you want to be conservative about checking his work you could require him to shut off the gas coming in and install a pressure gauge and air fitting on the new pipe. Then he would pressurize the new gas pipe to 10-15 psi and watch the gauge for 10-15 minutes to ensure there are no leaks. In my experience this is what they would require if he pulled a permit and had it inspected. This is the type of gauge he would use. https://www.homedepot.com/p/HOME-FLEX-15-psi-Pressure-Test-Gauge-11-801-007/206997510

Bruce

Thanks, Bruce! We are actually sort of near you, on the other side of the river, in Montgomery County. Our house is 22 years old, so that galvanized pipe might be old gas pipe. I am pretty sure he just reused whatever pieces he could, and the new black pipes are his. So would you recommend using all black pipe, or is his mix of old gas pipe (if that's what it is) and new black pipe ok? Then pressure test? I'm guessing my husband is concerned enough that he would run to Home Depot and try to test it himself before he lays the flooring. Our contractor's answer is always, "I know what I'm doing, don't worry" (and he's actually a bit offended when we ask) but then little things like not bleeding the gas line before pulling the appliance give us pause.

When I do natural gas work, I test it with soap solution.

Mixing galvanized with black iron pipe isn't something you do with natural gas.... and I don't know for sure it was done here - the photos aren't definitive. The elbows look suspiciously like galvanized.

What was used at the joints may be fine - if it was "pipe dope" for gas use. It's clearly not Teflon tape for gas. If it was caulk or something else, it's not fine. I've used yellow Teflon tape and I've used "pipe dope" but it all needs to be something that won't dry out and crack 10 years later - so you can't wing it with DAP Tub and Tile. Again, the photos aren't really clear... it just looks suspicious to me.

Update:

We had a master gas plumber come out during off hours to take a look, just for peace of mind. He said the gas work is ok; apparently gas for a cooktop doesn't have a high psi (I think he said like 1-2 psi?) and if there was a leak, he said you would smell it. He inspected the piping and said it was old gas pipe (which looks galvanized), and we were fine. He thought it was fine to mix new black pipe with old gas pipe, as long as sealed correctly. He said our contractor used pipe dope, which is good.

We also had him look at the rough-in plumbing and he said while not the most elegant way of doing the pipe work, all the piping does work. He pointed out some sloppy solder work, and a few spots where our contractor burned PVC pipes that were close by. The plumber said since those PVC pipes were air and not water pipes, that it was ok, although obviously not ideal. We could always fix those later if we wanted since they are in the exposed area in the basement.

He pointed out a few areas that we should ensure our contractor does over the next few days (like strap down a few pipes) and how he should run the refrigerator ice line. It looks like our contractor plans on doing the water line for the fridge through the floor and having the shut off valve in the basement, instead of behind the refrigerator. The plumber said behind the refrigerator in a drywall shut off valve box (like in a laundry room) is typical, but it is also acceptable to place it in the basement. If he does it in the basement, we should make sure he uses flexible steel braided tubing, not copper pipe, so that if there are problems in the future, they can use the old tubing to fish new tubing. And to place it near the back of the refrigerator (it's huge - we have a Subzero) so that if the fridge ever gets moved, it doesn't run over the line.

A big thank you to everyone who has offered advice and pointed out what might be wrong, so that we can prevent future problems! And for those in the same position, if the experts here see red flags, it is definite worthwhile to hire someone to come out and check out those red flags!!

Sounds like its coming along.

When our plumber ran the ice maker water line up to the valve box he used a T-fitting into the cold line under the kitchen sink, ran the supply line down into the basement, across under the kitchen, and then back up to the ice maker valve box. This means we can shut off the ice maker water supply from under the kitchen sink, which is very convenient.

Bruce