oliver2-44 9,756 #1 Posted January 27, 2023 (edited) While I seem to recall some long running bathroom remodel threads, I've been working to put this one off as long as I could. But leaks in the 40 year old copper piping has finally pulled me into it. This summer I had my 3rd hot water copper piping leak under the slab, you know, that warm spot through the concrete floor that gives them away. Fortunately I've found ways to reroute them verses cut concrete, but it was extra hot in the July attic for this last reroute. So this winter, while its cool in the attic, I'm working on running PEX for the upstairs bath and part of the down stairs that's in the garage/master bath wall below. The upstairs has a sink in the bath, and a sink in bedrooms on either side of the bathroom. Thankfully the back of all three sinks are accessible from this one closet. This closet is about 14 ft between 2 floors from the garage where I have access to pull in new lines. I'm not a copper expert, but this hot water line fitting below sure had a lot of corrosion going on! From the closet I need to run about 8 ft between the floors to the upstairs tub. Now you see it! Now you don't My wife has wanted to replace this "outdated" fiberglass sea shell design tub/shower for quite a few years with a "modern" tub and ceramic tile surround. I can't complain as she's really not one to always want the latest design or trend. But....I've resisted. But to access the shower and toilet piping the fiberglass meet Mr. Sawzall yesterday! Because I'm not exactly sure how things run branch off between the floors where I cant see, I've been working my way back from sinks and turning water off, cut-cap, see what still has water, and repeat, repeat. I won't get much done for the next few days as we have the grandkids! One on the interesting things about my past 3 leaks is they all have been hot water lines, and the all have been under the concrete below where they all header to the main hot water line and branch back into the stab. I wonder if the plumbers maybe kinked them making the bends from vertical to horizontal before the slab was poured. I've also seen where plumbers use a rebar stake to anchor these lines before the pour, and wonder if some dissimilar metal electrolysis corrosion could be going on. Thankfully the header where they all branch off is behind the utility room sink, so I now have a removable panel in the back of that sink cabinet. Anyone have any similar experience or knowledge on leaks in old copper? Edited January 27, 2023 by oliver2-44 3 Share this post Link to post Share on other sites
8ntruck 7,014 #2 Posted January 27, 2023 I'll agree with galvanic corrosion. Share this post Link to post Share on other sites
Jeff-C175 7,202 #3 Posted January 27, 2023 (edited) 2 hours ago, oliver2-44 said: similar experience or knowledge on leaks in old copper? The tee you pictured was leaking from a bad solder joint. When it's a tiny weep, eventually the minerals in the water solidify and seal it up... mostly... It still leaks, but never enough to really see a drip. I've seen lots of these. Not galvanic, rather plain old bad workmanship. None of the ones I've repaired were near concrete or dissimilar metals. I dissected a few decades ago and could plainly see where they were not properly soldered. Most likely not properly cleaned before assembly. It sounds like the contractor had an apprentice on the job. Edited January 27, 2023 by Jeff-C175 2 Share this post Link to post Share on other sites
ri702bill 8,327 #4 Posted January 27, 2023 Well water, I take it ?? Share this post Link to post Share on other sites
953 nut 55,281 #5 Posted January 27, 2023 That green stuff on the "T" is the result of a lazy plumber not cleaning off the excess flux after soldering. Flux is an acid and will corrode the copper. I think you are correct about the galvanic corrosion. I noticed a damp spot along a wall in one house I owned, not wet, just damp. It turned out to be galvanic corrosion on a copper line that was in contact with a drywall screw in the wall. The screw wasn't penetrating he pipe, it was just making contact. I had to cut a hole in the drywall, remove the screw, drain the water from the pipe and solder over the leak. 2 Share this post Link to post Share on other sites
Racinbob 11,082 #6 Posted January 27, 2023 Exposed copper piping installed by a skilled craftsman is a work of art. Unfortunately issues like yours are just one of many reasons Pex has become the better choice. Being so easy to install and being so much cheaper than copper is just frosting. This is the second house I completely replaced everything with pex. The first was a hideous mix of copper, iron, pvc and cpvc. This house was all cpvc with 47 zillion fittings. I did everything I could to minimize fittings and still I had over 200 crimps. Failure rate? A whopping 1. And that was because I forgot to crimp it. Fortunately both houses had pretty easy access to the plumbing unlike homes on a slab like most are in Florida. I try not to think about how I'd replumb our Florida home. I don't want to have nightmares. 1 Share this post Link to post Share on other sites
WHX?? 48,824 #7 Posted January 27, 2023 47 minutes ago, Racinbob said: Exposed copper piping installed by a skilled craftsman is a work of art. The Plunge @JCM comes to mind. 1 1 Share this post Link to post Share on other sites
peter lena 8,632 #8 Posted January 27, 2023 @oliver2-44 In addition to what you have done , we regularly use a squeegee to clean off shower walls , like every time you use it , also use a boat cleaner spray to wipe down and keep slick , 303 CLEANING SPRAY / FIBERGLASS boats , is what you want . it sheds water constantly . when you are dealing with a regular issue , set up a simple response to it . only if you want to , pete 1 Share this post Link to post Share on other sites
Darb1964 1,042 #9 Posted January 27, 2023 That copper fitting looks like a few that I have had in my house for the heating system with antifreeze in them. I thought it was the antifreeze that caused it. I see treated lumber under it not sure if that could have a reaction. I'm not a plumber, only know enough to get in trouble but I have done a lot in my home, most of it decades ago and know major problems. Concrete can be hard on copper, I had a friend that built a new house probably thirty years ago now that put heating lines in the basement concrete floor. He had big problems with it leaking and just capped it off, not sure on workmanship. Plastic seems to be the way to go now, less costly and faster. 2 Share this post Link to post Share on other sites
oliver2-44 9,756 #10 Posted January 27, 2023 1 hour ago, Racinbob said: Fortunately both houses had pretty easy access to the plumbing unlike homes on a slab like most are in Florida. I try not to think about how I'd replumb our Florida home. I don't want to have nightmares. Yes, with my house slab on grade plus an upstairs I'm working slowly trying to think and rethink about what goes where every time I open up a new spot in the floor or back of a cabinet. Unfornatualy the plumber that did this house had no rime or reason....actually I think he forgot to put a few things in slab. Most of downstairs comes up through slab, but one of the two master bathroom sinks and the master tub is piped from upstairs. The other master bathroom sink and shower are piped through slab like I would expect. Before I started I cut out the back wall of each sink cabinet and made it a replaceable panel. Then I used my little temperature gun and individually ran hot, then cold water at each sink/device and marked piping and gradually drew a partial piping drawing. Unfornatualy my drawing is only 60% complete as there must be some T's behind toilets (and who know where else) as I haven cut any holes in sheetrock except for the one upstairs closet. 3 hours ago, ri702bill said: Well water, I take it ?? Yes well water with a high lime/mineral content. We have a water softener which all water goes through. I wonder if its a good or hard thing on the copper, but I can say my hot water heater tanks have lasted a long time. @Pullstart in Texas their Hot Water Heaters as they don't get water hot enough to boil. We use Boilers at steam plants to make electricity! 2 1 Share this post Link to post Share on other sites
Pullstart 62,905 #11 Posted January 27, 2023 9 hours ago, Jeff-C175 said: Most likely not properly cleaned before assembly. Absolutely! As a bonus, the excess flux may have not been cleaned up after making the sweat joint. That’s just as big a no-no, but those look as if they weren’t cleaned well in the first place. 1 Share this post Link to post Share on other sites
lynnmor 7,307 #12 Posted January 27, 2023 1 hour ago, oliver2-44 said: Yes well water with a high lime/mineral content. We have a water softener which all water goes through. I wonder if its a good or hard thing on the copper, but I can say my hot water heater tanks have lasted a long time. Have the treated water tested to see if it is acidic. For me, here was never a buildup of minerals, the pipes just kept getting larger inside till there was daylight. My well water is highly acidic and copper plumbing and brass fixtures had the useful life of a Mayfly. I changed all of the plumbing to CPVC and that was a success. I change the anode rods in the water heaters every two years. 1 Share this post Link to post Share on other sites
Racinbob 11,082 #13 Posted January 27, 2023 12 minutes ago, lynnmor said: Have the treated water tested to see if it is acidic. For me, here was never a buildup of minerals, the pipes just kept getting larger inside till there was daylight. My well water is highly acidic and copper plumbing and brass fixtures had the useful life of a Mayfly. I changed all of the plumbing to CPVC and that was a success. I change the anode rods in the water heaters every two years. We were eating up anode rods like candy. Switched to a powered rod and that solved it. Share this post Link to post Share on other sites
Jeff-C175 7,202 #14 Posted January 27, 2023 2 hours ago, oliver2-44 said: I wonder if its a good or hard thing on the copper Softened water is generally harder on copper. It agressively 'pulls' the copper ions from the pipe over time. 48 minutes ago, Racinbob said: a powered rod and that solved it Yes! and it also can mitigate the hot water 'stink' that often occurs with heated well water. Share this post Link to post Share on other sites
oliver2-44 9,756 #15 Posted January 27, 2023 (edited) 3 hours ago, lynnmor said: Have the treated water tested to see if it is acidic. For me, here was never a buildup of minerals, the pipes just kept getting larger inside till there was daylight. My well water is highly acidic and copper plumbing and brass fixtures had the useful life of a Mayfly. I changed all of the plumbing to CPVC and that was a success. I change the anode rods in the water heaters every two years. Our water is not acidic, more on the alkaline side in the lime stone hill country. I have it tested every couple of years to adjust my softener Edited January 27, 2023 by oliver2-44 Share this post Link to post Share on other sites
oliver2-44 9,756 #16 Posted April 28, 2023 Well a few weeks ago this project grew. Had our 4th under slab copper leak. it was the hot water to the Master bath tub. All of the leaks have been in the hot water copper, and seem to be in the bends where they come from horizontal under the slab to vertical above the slab Initially I was only re-piping the upstairs since I was replacing the tub. These are water lines in the truss space between the upstairs and down stairs Being a retrofit, there wasan't a good way to use clamps to secure the pex, so I uses expanding foam to several places This hole is in the middle of the upstairs bathroom flood and takes water down to the master bath sink. Lots of measuring to hit the correct spot be come down to the back wall of the master bath sink cabinet. Black duct tape was to temporarily hold it in place closed back up Fortunately this floor was going to be redone with laminate anywhere. Not my neatest/prettiest piping job, but retrofitting and sneaking it between floors an down walls was a challenge Everything except the main tie to the incoming cold water and tie to the hot water heater is done. All the new piping is in service being fed from a temporary hot and cold water feed. I have to remove some floor decking in a storage room to make the final connections. Share this post Link to post Share on other sites