90 year old leaking sewer pipe - replacement

JHZR2

Staff member
Messages
46,418
Location
New Jersey
Went down in the basement tonight to find a water spot on the floor. It hasn't rained, and we havent gotten water in our basement in years. I tracked it and got to this (pardon the dirt and bad parging): I know that this evening before we went out for dinner, my wife and I both used the bathroom, and the dishwasher was draining all at once. If there was ever water before, it was local and small, never dumped water that flowed to another point and made a puddle like it did this pm. I had seen these for a while now: There is already a patch of about 3 feet of 4" PVC connected by two donuts. It is a long way away from the crack where the leak is, and those little rust spots are along the length between the patch and this crack. So my intent is to just replace the whole entire length. There are no vertical pipes coming off it so the weight loading should be low. As a DoD employee, I am furloughed tomorrow, so rather than supporting our military, I'll be working on this, DIY. I have a sawzall, but no grinder or chain cutter for CI pipe. The pipe I want to cut out is probably 15-20'. My main issue is this: It goes through a poured concrete wall (accessible on both sides, just two 'rooms' in my basement), which will be tough to get out of there I guess. So my plan is this: 1) disconnect the existing patch 2) start cutting back manageable lengths of the pipe for removal 3) cut to about 1 foot on either side of where it goes 4) use sledge hammer to force pipe through wall 5) clean CI pipe on either end to be smooth and clean metal 6) cut and attach 4" PVC drain pipe to CI pipe with donuts, torque to spec. About right? Questions: - Will there be a lot of water in the drain pipe? I assume it is higher than the sewer pipe in the street, but how much of a mess should I expect? Any chance of the town sewer pushing water back up the pipe? Our drains are clear and work perfect. - Am I crazy to think that I'll be able to cut the pipe with my sawzall vs another tool? The pipe is a few inches off the ground and maybe an much from the wall. - For the final cuts at the ends where I'll use donuts, should I clean/sand/paint/prep the CI pipe prior to attaching? - My sewer pipe I think has an open exposed grate out in my driveway apron, where my pipe connects to the town sewer system. I'd think that this would help mitigate some sewer gas, though I never smell anything (sulfide gas is heavier than air I suppose). Since the pipe will be exposed, I'm sure sewer gas will diffuse in. What is the best way to clog it? Wet rag or plastic bag? Thank you so much for your advisement!!
 
Messages
3,511
Location
Cincinnati, OH
your sawzall will work well. use a good bi-metal blade. i like Lenox blades personally. its hard to say if you will have a mess. the sewer will not drain from the city, as your pipe will have to have fall going to the main if it has been draining. generally old cast pipes are halfway filled with goop so you will probably find some of that inside the pipe. your plan to patch sounds like a good one. you can buy 4" furn-co boots at most hardware stores. Good-Luck, as always be prepared to improvise!
 

wog

Messages
243
Location
massachusetts
Saws all will be fine, the pipe will prolly collapse. It looks. You may need support for other sections otherwise you could be chasing the whole length. Use grit blades or titanium goes thru like butter. If no one uses water all nite the pipe might be dry sort of. The mess won t be to bad.get some barrels to catch all. Make hole bigger if you have chipping gun makes easier to slide in full length of new pipe good luck!
 
Messages
13,449
Location
North Carolina
I would think about moving some air in there as your work. Once the pipe is opened who knows what gasses will escape. A large shop vac blowing into the room? Since its not a septic tank system probable not too much methane. I have used wet towels in the past. But if it stinks bad , you will be with it until you are done. You may need an inpact/air chisel to chisel out around the pipe.
 
Last edited:
Messages
2,630
Location
Deep in the heart of Jersey
I've worked with pipes for a few years so this is just a heads up. After you make your cuts, visually check the pipe leading to your sewer. It may need to be cleaned out to prevent future blockages.The time to do it is now.Cast pipe can be 50% or more blocked. So you might need to replace more pipe in your house then you planned on. As long as you can get to it easy, change it out now to save future headaches.,,
 
Messages
9,153
Location
Marshfield , MA
I had to repair the line outside length of "Orangeburg" a tar impregnated cardboard that was used pre- PVC. Anyway you may have some water. It wouldnt hurt to be prepared with a bucket. A sawzall is what a plumber would use. Cast iron is soft. I like the rubber rings with hose clamps and PVC end to end replacement. If you have to use the primer and the glue, rig a fan or do it outside. It is nasty stuff to get a whiff of.
 
Messages
3,511
Location
Cincinnati, OH
Originally Posted By: BigCahuna
I've worked with pipes for a few years so this is just a heads up. After you make your cuts, visually check the pipe leading to your sewer. It may need to be cleaned out to prevent future blockages.The time to do it is now.Cast pipe can be 50% or more blocked. So you might need to replace more pipe in your house then you planned on. As long as you can get to it easy, change it out now to save future headaches.,,
+1 ^ and you can use rags or plastic bags to stuff inside the old pipe to block the smell until you are ready to tie it back in.
 

JTK

Messages
13,635
Location
Buffalo, NY
On my last home I used my grinder to cut out a section of cast iron drain pipe. Went through like butter and left a nice straight cut. Unfortunately with extremely sharp edges that I cut my hand on. @#$! I then used some nice thick Fernco couplers to tie in the plastic. andyd, just the word orangeburg throws me into Tourette Syndrome fits. Love to give the engineer who came up with that a solid D-slap.
 
Last edited:
Messages
2,081
Location
California
+1 on the Lenox blades. Make sure you have several available. I like the 810R for cast iron, and there should be a titanium version available. If not, the regular 810R will suffice. Sometimes there's no sewer gas to speak of, other times it can be really nasty. Pvc may need more support than the cast iron has, so that it won't sag. Code book says every 4' for plastic. Oh, and it's likely that there will be a semi-liquid residue in there that's blacker than the pits of [censored]. It smells bad, and stains.
 
Messages
449
Location
Ohio
I did that exact job when I was in my 20s in a rented house. Forget the sawzall. A grinder is what you need. Plus get ready for some really nasty sludge. Latex gloves and some clorox with cleaner are in order.
 
Messages
2,239
Location
CA
If you have a way to positive-pressure the air in your basement, say with a decent fan at the entrance door, you can deal with the sewer gas without cramping your workspace. Just don't negative-pressure it. It doesn't take much at all; the other end of the pipe eventually reaches outside air pressure.
 

JHZR2

Staff member
Thread starter
Messages
46,418
Location
New Jersey
Originally Posted By: SVTCobra
I will go out on a limb - could you install a new pipe next to the old one and abandon the old one?
Not really. The rest of the piping on both ends looks perfect, and there is a small sideways wye that mates to our laundry sink.
 

JHZR2

Staff member
Thread starter
Messages
46,418
Location
New Jersey
Originally Posted By: spackard
If you have a way to positive-pressure the air in your basement, say with a decent fan at the entrance door, you can deal with the sewer gas without cramping your workspace. Just don't negative-pressure it. It doesn't take much at all; the other end of the pipe eventually reaches outside air pressure.
Yes definitely. I know where the fresh air box is at the street do I'll probably open it to minimize restriction. I'll still cover with a plastic bag or something too.
 
Messages
187
Location
PA
you've gotten very good advice so far. i replaced a short piece of cast iron drain pipe for my washing machine several years ago. Tried using a blade but was extremely slow. I rented a pipe cutting tool from Home Depot. Not sure the exact name but it involved a sharp chain-like material that wrapped around the pipe and you slowly crank pressure. It's a larger version of mini pipe cutters that you increase pressure, cut, increase pressure, cut...until it finally cuts through the pipe. It took about 5 minutes to make 2 cuts. You'll need at least 4 cuts. It didn't cost much at all to rent. It saved a lot of time. HOpe this helps. Good luck. PS - Think about how you plan to get the full length PVC pipe into place. You may have to chisel out more concrete.
 

JHZR2

Staff member
Thread starter
Messages
46,418
Location
New Jersey
Thanks. Yes going to hd tool rental is on the list for a little later for that cutter. I think in order to put in the wye for the sink I'll have to break it up a bit so it won't be a true full length run.
 
Messages
1,673
Location
new jersey
If I were you, I'd rent a Chain Snapper from HD. It's only $25.49 with tax for 4 hours. I know this because I literally just got done with doing my basement bathroom. I had to pull the old cast iron pipe from under concrete and install all new PVC. And then remodel the whole bathroom. The old cast iron piping had become clogged as they all do after awhile. My house is around 70-80 years old as well. I tried cutting it with a reciprocating saw, and a special blade from HD made for cutting cast iron. I made one cut with it and it took about 45 minutes. I attempted to make a second cut, but it took way too long in an uncomfortable position. So, I said the [censored] with it and rented a chain snapper. Literally cut the Cast Iron pipe in a matter of seconds. Needless to say, you need the right tool for the job! lol
 
Messages
5,532
Location
Canada
If I am buying a house I would take a dim view of Patched, old, cast iron pipe. Bite the bullet and replace the whole run, or at least all the horizontal pipe in that run. Smashing the pipe is often quicker and saves multipal cuts (and blades) Especially where the pipe goes through a wall. If you can, join at a coupling. You can chisel out the old CI, clean and calk in the new PVC/ABS Smooth, un patched pipe is less likely to accumulate gunk and cause a blockage. AND Looks better. Leave the Rubber bandages for the quick and Dirty fixes.
 
Last edited:
Top