I’m working on a brick home built in the 1950’s. The walls are plaster on cinder block with brick on the outside. The kitchen cabinets are going to be replaced soon and I would like to take the opportunity to update the drain plumbing. Currently the home has 1″ galvanized plumbing in the kitchen. I have already replaced all but the kitchen drain section with ABS. From the trap the galvanized piping runs at an angle to a void in the wall where it T’s up to the roof vent and down for the drain. Near the bottom of the wall the cabinet is cut out to allow the drain line to go around the foundation and into the basement. I have come up with three options to update the plumbing. 1. Replace the drain and vent lines with 1.5″ ABS exactly as they are installed now. 2. Cap off the T and run a new drain line straight down under the sink through the floor. Under the floor tie in the new drain and use the old line for a vent. (This may be considered a broken vent). 3. Run a new drain line through the floor up to a sanitary T. Run a new vent line from the top of the T over to the existing void in the wall. I want to make sure the drain is as efficient as possible and doesn’t make the cabinet installation too difficult. Due to the type of construction it’s not possible to hide the drain line in the wall. Your opinions are appreciated! I tried posting this under a seperate section of the website but only got one response, hopefully you guys will have some good ideas for me. I’ll try to post some pics tonight or tommorow. |
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My only experience with galvanized pipe has led me to the firm conclusion that it should be eliminated in every instance. I looked for my posts from the spring which included photos of the insides of a 50 year old tub drain and vent constructed of 2" galvanized - it was completely clogged with rust particles flaking of from inside the pipe - but could not find them. I attached a photo showing typical cinditions I found. Ultimately, I took out all the GP down to the cast iron stack and removed the galvanized pipe used as a vent for the same reason.
My conclusion: Passage of anything - fluids, solids and air - is severely reduced over time within a galvanized pipe, and it needs to be completely replaced with ABS. As long as you're in the middle of renovations with walls and cabinets open, replace it all now and save yourself trouble down the road when it's finally completely blocked but the walls are sealed. The expense of replacing GP with ABS is minimal, and the extra time required now is not much of a consideration in light of the overall project.
Good luck.
Hey! How did you get a picture of the pipe I just pulled out of my 104 year old house? Galvanized pipe is just bad. I found spots in the vent that were eaten away by an older plaster patch job....that's not a mistake, it's rustic
Wow thanks for the pics. This section is the last bit of pipe I have to replace. I already took care of a nasty tub drain and vent last year.
Do you guys think I should change the design or keep it the same?
OK here's a shot of what is going on downstairs. As of right now I'm thinking about running the drain line up through the floor below the sink cabinet, then I'll T off the line and run over to the vent line in the wall. I think that'll reduce the amount of cutting in the new cabinets.
It's a little difficult to tell what you've got there, but if anything is going to be visible, I would definitely clean things up simply for the aesthetics.
If the sink will be mounted as part of a cabinet which will enclose the drain/supply pipes than you only need to clean things up to make them work and comply with code, as well as to make sure no little critters manage to find their way into living spaces through unintended openings left in walls/floors, etc.
And, make sure your old shut off valves on your supply pipes work properly. Now's the time to replace them if they're stuck open or if they drip once you turn the handle.
Looks like a clear lava flow coming out of that cut in the wall to the left - what is that stuff? Is that the old galvanized vent pipe you mentioned earlier visible in the background of that cut?Griff
Griff-
Thanks so much for the advice. Yes the existing galvanized line runs back into the wall to a T where it runs up to the roof vent and down for the drain. It kicks back out of the wall at an angle to clear the foundation. I was trying to get rid of the part that kicks out because it means cutting into the adjoining cabinet.
Do you think running the new drain line up through the floor directly below the sink and then over for the vent would be the best way to handle it? Unfortunately I can't move the vent line. I'll attach a larger photo.
I can't picture all that is going on, but I can tell you one thing I learned about old pipes is that if you cap them off on the bottom end, but they stay open somewhere else, you will get condensate buildup in the pipe, which will probably eventually rust through and leak all over.So if you cap off some pipe on the bottom end, be sure the top is capped off too. If you are using the pipe for a vent, don't have some tail end going off somewhere.
I think after what everyone has said it's best to remove all of the galvanized piping. After looking at the piping again I realized that I ran 2" ABS instead of the 1.5" ABS I noted earlier. So I'm replacing the 1.5" galvanized with 2" ABS to the sink. I think I'll run a 1.5" vent through the roof since the hole is already drilled for it.
I'm not a plumber so I'd take any advice I give you with a grain of salt. But, my general understanding is that every drain requires a vent (or, at least, direct access to a common vent) in close proximity to the drain. How far from the drain the vent can be is unknown to me, but my guess would be that the longer the distance the more likelihood there will be a problem.
Am I correct in understanding that you are not replacing the galvanized vent that's shown in the photo but are planning to vent somewhere else? I think you could safely drain straight into the floor and "T" off that drain through the wall to the galvanized pipe's replacement (if that's what you're planning to do) in order to avoid entering the wall "T" into the vent and then having the drain come back out as per the photo.
If you're planning on draining straight into the floor but connecting to a vent some distance away from the sink (especially from some point under the floor), then things might become problematic. It's also beyond my competence to give you advice at that point, especially without seeing your plans.
If you think you need advice, trying sketching out a diagram with notes regarding distances, pipe size and slope per foot, scan that in and attach it as an exhibit to your post. Hopefully one of the plumbing guys will answer you question. They were very helpful to me, and very generous with great advice, over the summer when I was working on that galvanized tub drain mess in my mother-in-law's house.
Good luck.Griff
Thanks a lot Griff, your help is appreciated. I think you're correct about running under the floor and connecting to the vent, it's a bad idea. Right now I'm down to replacing the line as is except using a 2" drain and 1.5" vent all in ABS or running down through the floor as you described.
I'll see if I can draw up a plan for each one to graphically describe what's happening.
If it helps, the current issue of Fine Homebuilding has an article about a new method to vent a kitchen island with a sink (Since it's completely open above the sink, there's no place to run a vent up to the roof).
Uses an "Air Gap" type of device to let air in to prevent a suction from developing, but is supposed to prevent sewer gasses from escaping.
Take a peek and see if that helps.Griff
Any plumbers online to offer advice to HO Sumday about his plumbing concerns?
How far away from a drain can the vent be located? Especially when the horizontal portion of the drain taking water away from the sink runs underneath the floor. Prior galvanized pipe had a short horizontal run to a "T" - down for drain, up for vent. Galvanized has to be replaced for all the obvious reasons.Griff
"Do you think running the new drain line up through the floor directly below the sink and then over for the vent would be the best way to handle it?"I'm not a plumber, but I think this is exactly what you want to do. The vent stays nice and close to the drain/trap and you are not cutting up the cabinets.Be sure the tee off of the drain pipe to go to the vent is after the trap.Rich BeckmanAnother day, another tool.
I guess the pipes were friendly. Horrible stuff, isn't it? I'm just glad to be rid of it.Griff
I agree about the galvanized....Get Mr. Sawzall and a metal cutting blade and cut it out....The vents seem like they would be ok, but everything else is trash...
I just cut a bunch of 50 yr old stuff out and replaced it...Had a vent that looked fine, and would have had to be hard rock mined out .. So I left it..