Kitchen --> Replace Old Sink Drain Old House Plumbing Repairs: Replacing Sink Drain Plumbing Bringing It Up To Code With Very lousy sink drain pipes literally fall apart and are replaced with a new slip-joint fittings, P-trap and flexible coupling. valve is added for proper venting. New Sink Drain Pipes Bruce W. Maki, Editor One evening my neighbor told me about a plumbing problem he wasThe kitchen sink in their 110-year-old house wasHis wife was using a plunger on the sink drain when suddenly the drain pipe fell off, dumping dirty water all over the bottom of the cabinet and kitchen floor. [See Tools and Materials] comments below the article] The drain plumbing looked like this before The whole arrangement of drain piping was doneFor a start, flexible drain pipes just don't The section between the two red arrows had fallen off from the agitation of plunging the The kitchen sink was actually straddling

two separate base cabinets, so the drain to the left basin went through a hole in the cabinet partition. wasn't a problem... it's just a bit unusual. I began by taking apart the old drain The nut (lower arrow) was actually cracked, and barely held the trap together. applied a heavy layer of pipe thread compound to this Note that this entire S-trap was upside down. The nut is normally on the top piece... but I'm not sure This part of the trap had been merely inserted into the end of the 1½" galvanized steelSince the steel pipe had been cut off, and was not threaded, the slip-joint nut didn't actually engage Surprisingly, this connection didn't leak, even when the drain was backed up. The proper approach is to use a flexible rubber coupling, commonly called a "Fernco". I used a small fine file to remove the burrs and rough spots on the end of the steel pipe. to take chances with the rubber coupler leaking.

On this fitting below the sink tailpiece (arrow), pipe had been installed WITHOUT a Or perhaps the nut had become cracked and was thrown away by an unwitting homeowner. Surprisingly, this connection didn't leak badly... even when the sink wasBut water had been seeping out somewhere, leaving these brown stains. After I removed the white plastic pipes I tried to remove the metal nut (red arrow) on the bottom of the sink basket. I placed a basket wrench in the drain (from above) and had the homeowner hold the wrench to keep theThen I used a large pair of Channel-Lock pliers to remove this metal nut. corrosion on the threads made it very difficult to Despite our efforts, the basket rotated a bit. When the sink basket moves it almost always leaks. had to remove the sink basket on both basins. Of course one of the the large ring-nuts broke, so we had to buy another. After the baskets had been removed, I

cleaned up the sink. Note spots around the rim of hole. alcohol wouldn't remove these spots, though I could scrape them off with a screwdriver. I figured these spots were hard water deposits, so IWeight Loss Support Groups Memphis applied some calcium and rust remover with aCheap Bed Comforters Bedspreads stiff bristle brush, and then rinsed thoroughly withShower Head Will Not Stop LeakingThis removed all of the spots. Once the sink had been cleaned up, I installed the baskets. Instead of using plumber's putty, I used clear silicone between the underside of the basket and the sink. sink baskets in an earlier article. If I tried to attach anything to the basket while the silicone was soft I would probably

squeeze out the caulking, creating a mess and possibly After the silicone around the basket rim had cured for an hour, I installed the tailpiece. I used a dab of TFE pipe thread compound on the metal threads and used pliers to tighten the metal nut. This is a sink drain kit, which we got at Home Depot. This set of pipes connects the two basins together and directs the drain water towards the trap. After I installed the drain kit, I had two pipe ends (arrows) that needed to be joined together.I also needed a trap and an air admittance valve between these two pipes. Since the end of the steel drain pipe was rather rough, I applied a thin layer of pipe thread compound and spread it around. I was hoping that the pipe dope would harden and form a tight seal that would prevent leaks. It must've worked because four years later it still doesn't leak. I slipped the flexible coupling (a.k.a. "Fernco") over the end of the pipe.

Then I tightened the screw on the band The instructions say to tighten the band clamp screw to 50 inch-pounds of torque. This is an air admittance valve, which we bought at Home Depot for about $24. part added to the cost of the repair, it also improved the flow of the sink drain. This air valve came in two parts, which need to be screwed together hand tight only. Note: There needs to be an inch or two of room above the air valve, in case the top section needs to be removed for maintenance or replacement. The other important drain component is a tee fitting. several types of tee fittings available. I used a sanitary tee fitting (seen in the picture below) which has a curvature to help direct drain water down into the vertical pipe. With all the necessary pipe and fittings in my hands, I laid out the drain line connection from the pipe below the sink to the old steel pipe that poked up through the floor.

Laying Out PVC Pipe Fittings For A Kitchen Sink Drain: When figuring out the layout of plumbing systems, I always do a "dry fit" without glue before committing to First I assembled the P-trap (1 and 2) and installed them on the vertical drain pipe (below the sink) making sure I had at least one inch Then I established the height of the sanitary tee fitting (3) which gave me the length of the first section of 1½" pipe Next I determined the distance of the slip-joint adapter (4) from the tee fitting, giving me the length of the short lateralI could have made piece P2 a couple of inches longer... and just cut fitting #2 a bit shorter. The air vent (the blue-striped part above #5) needed to be at least 4 inches above the water level of the trap, so I cut pipe P3I placed the air vent connector hub (5) on top of this pipe to make sure everything would fit below the sink Warning About Dry-Fitting PVC Pipe And Fittings:

When dry fitting PVC pipe and fittings, the pipe won't slide into the fitting's hub all the way. But when PVC cement is applied the liquid acts like a lubricant and then the pipe can easily slide all the way in. that the glued-together assembly of pipe and fittings will be a little shorter than the length of the dry-fit assembly. It seems that during dry fitting the pipe will enter the hub about 2/3 to 3/4 of the actual overlap amount. You can force the pipe in farther but it will be difficult to remove. I simply compensate by making the dry-fit section of pipe a little bit longer than the desired final length. With this size of pipe I'd estimate that I add a quarter-inch per to verify that the trap can be assembled and taken apart. It's possible to glue up the drain pipe and then be unable to get the slip-joint fittings into place because supply pipes or cabinet walls are in the way (though most sink base cabinets