*
After reading the “sweating cooper lines thread” and observing some plumbing knowledge/experience I figured I’d try kicking this one around. I have just finished plumbing my new house and would like any feedback on the best ways to test supply(copper) and DWV(pvc) for leaks before drywall. I have been advised on pressurizing the copper for a 24 hour period and monitoring the guage, along with filling the pvc until it comes out of the roof. Any other thoughts ?
Discussion Forum
Discussion Forum
Up Next
Video Shorts
Featured Story
Skim-coating with joint compound covers texture, renews old drywall and plaster, and leaves smooth surfaces ready to paint.
Highlights
"I have learned so much thanks to the searchable articles on the FHB website. I can confidently say that I expect to be a life-long subscriber." - M.K.
Replies
*
Dan,
When I did my remodel I put an air pressure gauge on the supply line, and filled with 100 psi of compressed air. I figured that was better than filling with H2o in case I did have a leak. I also used the method of filling the vent full of water and looking for leaks, unfortunately the plug that I used to block the toilet flange popped out when the vent was full of water.
When the inspector asked why the crawl space was so wet, I told him the story. He laughed and told me that had happened on a multi-story condo that he had inspected once.
*If you have a catastrophic failure with 100 PSI of air, you can have missiles flying around. It is much safer to wet test a supply system, if need be to 1.25 times working/design pressure. This is common in industrial piping.
*Dan:The methods you describe are the way plumbers around here do it for new house construction. No, I didn't add any value, except to say that you have all the info you need unless you are unsure how to perform the tests and need some info in that area.
*Sure Matt, let it fly, any info is good info.
*To test the supply lines all you need is a pressure guage, an air valve (as used on a well water pressure tank), a brass "T", a bicycle tire pump, and some soapy water in an old Windex bottle. If the lines are going to leak, they will do it at 10 or 15 pounds of pressure and it will show up quickly. If the lines will not hold pressure, check each joint with the soapy water. The bubbles will tell the tale. Don't forget to "bridge" the hot and cold water lines at the water heater location.
*As a DIY, I'd suggest you go the air route in the copper piping. Not only does the water make a mess if there is a leak, but then you have to drain the whole system, use the Wonder Bead trick, etc. If you were really sure you have no leaks (i.e. you didn't on the last few houses you plumbed), then it is easier to just open the supply valve and pressurize with water.Mark's point about the stored energy in 100 psi air is true, but it more true in large diameter piping and especially true in brittle (plastic) piping rather then in metal which deforms in failure.The test in DWV piping (not ABS, the black stuff?) can be done with test plug and 5 psi air or by filling the standpipe with water. Same cavaets as above. -David
*Around here air test is allowed on supply lines in freezing weather, must hold 100 psi until inspector shows up. 100 psi of air is what we use all the time in our compressor hose systems. Air supply systems I have plumbed for shops run at 200 psi ( two stage compressor ). Why would I worry about testing at half the pressure I normally work with? I am not saying air pressure is not dangerous, it is just a tool we use with caution.Also around here the DWV is wet tested only to the top of the highest bathtub. The vents above this level are not tested.Frank DuVal
*A couple months ago, I had an inspector tell me to remove the 100 psi guage and install a 15 psi one. The reasoning he gave was that a small leak would register on a 15lb guage a lot sooner than a leak would w/ a 100lb. one. That was on a gas line.Also, around here all DWV piping is ABS (or iron) - not PVC. But that's probably just his word for "plastic pipe".Geo.
*All DWV around here (chicago)is either copper, cast iron or pvc (white) sch40 astm 260psi @ 73 degrees Fhttp://www.bristolpipe.com/Product_Details/PVC_DWV_details.html
*I learned my plumbing in Denver in the 1980's. ABS and PVC were almost even in popularity. The ABS is more flexible and the PVC is stiffer/stronger. I preferred the ABS because no primer needed and the fumes seem less toxic (MEK vs. tetrahydrofuran in the PVC glue). A really good plumber I knew preferred PVC because he felt it was stronger and neater looking, and the glue less ugly when dripped on the subfloor. (That was before red hot blue glue, what I call "Superfund site in a can.") Both kinds of plastic DWV are good, but ABS seems to have grown a popularity lead here in S. California. Oh yeah, the ABS is less inclined to UV embrittlement in stacks due to the black carbon pigment they add in manufacture. I also hear that plastic DWV is now allowed under slabs in Colorado, which was not the case in 1984 there - you had to use iron. That always irked me because shifting soil cracks the iron while ABS can flex some to accommodate the movement. Is this code change true everywhere?Bill
*I'm speaking as a pure amateur here but I see and hear plumbers around here talking about testing their plastic with smoke bombs instead of water. (Less mess if there is a leak.) I know you can pick em up at the supply house.
*Around here the inspector will want to have water in the DWV when he shows up for top-out. 6 ft. or so in the vents will suffice. Took me three tries in my two story to keep the plug from popping out of the 1st floor closet flange. Big mess. But seeing how much pressure is exerted leaves me feeling pretty confident that it won't ever leak. 100 psi on your copper will definitely show up any pinholes. I had one, and when the house was quiet you could actually hear it hissing.
*IMHO, 24 hours for a test is good enough for the pros, but I would leave DIY pluming joints exposed with water turned on for at least a week.Don't ask me how I know...
*
After reading the "sweating cooper lines thread" and observing some plumbing knowledge/experience I figured I'd try kicking this one around. I have just finished plumbing my new house and would like any feedback on the best ways to test supply(copper) and DWV(pvc) for leaks before drywall. I have been advised on pressurizing the copper for a 24 hour period and monitoring the guage, along with filling the pvc until it comes out of the roof. Any other thoughts ?