“I use CSST exclusively. On top of the time savings, I don’t have to purchase a $5,000 threader, which is required for steel pipe.”
— Kevin Wagner
WAGNER’S STORY
Pennsylvania builders Pusey and Raffensberger hired Kevin Wagner to rough in and install a dual fuel furnace using heat pumps and natural gas for a four-townhome development. He won the contract largely because of his affordable bid. Wagner’s bid was less expensive because he proposed to use CSST flex pipe for the gas line, which would allow him to complete the project faster than contractors using steel.
[IMAGE: This townhouse–which looks like a single-family home–has an elevator and other accessibility features.] “I use flex pipes on smaller projects such as this one because it cuts down on labor time,” Wagner says. “This project took about two-and-a-half hours to do everything, including the final touch ups and putting the manifold in. If I used black steel pipe, I would have had to thread the pipe, which probably would have taken me 4 to 6 hours.”
“Overall, it costs less in materials to use black iron pipe and thread it, but when you factor the labor in, flex pipe is much cheaper since CSST is so much faster to install in short runs. However, if you’re doing a long run, maybe a 100-foot straight length, flex pipe doesn’t make financial sense since black iron pipe is pretty quick on straight runs.”
PROJECT DETAILS
“I ran about 60 feet of the ¾” CSST for the main line, and probably close to 60 feet of ½” line for the furnace, fireplace, and water heater lines,” Wagner says.
“I put a manifold in the basement down by the HVAC unit so the homeowners could add lines if they remodel, but it doesn’t really matter where you put the manifold. You don’t even have to use a manifold. Instead, you can just put in t-fittings. You might save some time, but it’s less handy in the long run than the manifold, which has extra spaces for future retrofits. You can also turn the main gas line off right there.”
“Flex pipes come with all sorts of accessories, including the manifold and other fittings. Each manufacturer has a slightly different manifold, but they all have about four or five ports of ½” outlets, with one ¾” outlet for the main. Most are made of black iron.”
“Materials probably cost about twice as much for the CSST as for the black pipe. For this project, they cost about $350. Flex pipe costs about $1.70 a foot, fittings are about $7 to $12 depending on the size, and the manifold costs about $27.”
INSTALLATION TIPS
“You have to pay attention when you install flex pipe because the pipe has a memory when you uncoil it,” Wagner says. “If you get a loop in it, you can’t just untwist it to get it straight. It’s not like an electrical wire where if there’s a little twist in it, you can still make it look good.”
“CSST is flexible, but it is also sort of thin, so it can kink. You’re not supposed to make a sharp 90-degree turn with it. If you do need to make a 90-degree turn, use a fitting.”
“You have to treat it somewhat like water pipe. You have to protect it wherever it goes through studs and where nails can get to it. But the manufacturer gives you all kinds of stud protective plates.”
“You also have to make all the other tradesmen aware of the flex pipe because it is more vulnerable than steel,” says builder Dave Pusey. “It is possible to put a leak in the CSST pipe with a drywall screw or shoot a nail through it if it’s not protected properly, which you don’t have to worry about with conventional cast iron pipe.”
WHEN TO USE FLEX PIPE
“If you only have straight runs in the basement, it probably wouldn’t be economical, but flex pipe is a real time saver if you’re also roughing gas pipe into the second and higher floors,” Wagner says. “If you had to get gas piping up to the third floor of an apartment for a washer and dryer, for example, the time savings would be huge. Once you start going up a wall, across a floor, up another wall, and across another floor, with black pipe you would have all those joints that you’re trying to fish hook a pipe through. That’s where you’re saving your time with CSST.”
Yellow, flexible gas pipe is run from the main with ¾ inch line through a manifold, and then to the water heater and fireplace with ½ inch lines. The furnace is fueled almost directly from the manifold with a few inches of fittings. “Another place where it would be a big time saver would be on a remodel job,” says Pusey. “If somebody wants a gas fireplace over in a certain part of the house, flex pipe is going to be so much easier to install because once you get a hold of the end of it, it’s almost like you’re fishing wire. That makes CSST the least invasive way to install a natural gas line, which homeowners like because it’s very economical and clean.”
CERTIFICATION
“Most manufacturers require certification to install their flex pipe product,” Wagner says. “The supplier gives you a book and tells you about the product, and then they give you a test that’s essentially open book. The entire process takes about an hour. It’s an easy certification.”
