Replacing all drain pipes

[amconnor]

Hello everyone,
As this is my first post I just want to say that I have really appreciate everything I have learned cruising through the various forums on this site and I look forward to being a part of the community here. I write today because I need your help.

My wife and I just purchased a new to us home that was made in the 1950s. After living in it for a while we quickly learned that we were having a lot of plumbing issues. Unfortunately, upon further inspection, we have discovered that almost all of the galvanized and cast-iron pipe that was used throughout the house is almost rotten through to. We have made the decision to update everything with PVC out to where our pipe enters into our septic.

Much of our pipe is buried underneath of our concrete slab in our basement. While I would love to pay someone to do this, I simply can't afford to right now. My knowledge of plumbing is limited but I'm a quick learner and am not foreign to DIY projects. I would like some help formulating a plan of attack here.

What is the best way to open up a large amount of concrete floor (60-70 square feet)? I live close to tool rental companies and have looked into jackhammers and concrete grinders. Would one of these be better than the other?

Thanks for sharing your wisdom,

Andrew

 

[Reach4]

I am not a plumber. It is sometimes easier to run the drains out into the yard, and then around to the septic tank.

The line to the septic would usually be through the wall of the basement. Only when there is a large slope, are you able to gravity feed the septic tank from a basement floor drain. The lower basement drains usually feed into a pit with a suitable pump. The waste gets pumped up and joins the sewage.

The steps I am picturing that you would go through would be similar to what people do to put in overhead sewers.

So what height is the line to the septic tank?

 

[Sponsor]

 

[amconnor]

I have attached some pictures.

The run from my house to my septic is very short maybe 6 feet and my house is on a significant hill.

All of my plumbing runs to where the downstairs bathroom is and the wall between the washer and dryer and the bathroom is where it leaves the house.

 

[Reach4]

This is where the sewage leaves the house? If so, all lower sewage gets pumped up. On second thought, I guess that line turns down and goes under the basement slab. Right? Or does it turn outside before it gets down to the slab?

 

[amconnor]

This is where the sewage leaves the house? If so, all lower sewage gets pumped up.

No, i apologize for the confusion. It does a 90 there and goes down into the concrete then turns out towards the septic

 

[amconnor]

So does anyone have any suggestions on how to open up my floors? Would a jackhammer be a bad idea? Have heard about diamond grinders, but know nothing about them. Is this the machine I would use? https://www.homedepot.com/tool-truc...9kljovX-d_Vz59NSuevgZDo9PYj2NXhBoCsxMQAvD_BwE
Thanks

 

[Sylvan]

When I had to replace 8" cast iron in a building 36" under concrete I hired a company that used concrete grinders and let them worry about the rebar and paying for the wheels as they ate quite a few.

Jack hammering does not create neat openings so when I have to have my employes do the cutting we use a concrete grinder and then jack hammer between the neat grinder cuts

 

[Terry]

I hire someone with a wet saw and help him by moving things around, and handling the wet vac while he's creating concrete slurry. No dust that way and the lines that are cut are clean and easy to pour to.

The guy I hire has one that uses electricity. I would not use a gas model in a home.

 

[Reach4]

Should amconnor get somebody to map out the path of the existing pipes before entering the slab? Or should he only care about where he wants the new pipes, and leave the old stuff in place... and cut through it when encountered?

 

[Terry]

Should amconnor get somebody to map out the path of the existing pipes before entering the slab? Or should he only care about where he wants the new pipes, and leave the old stuff in place... and cut through it when encountered?

If he is replacing all of the pipes, then the cuts only need to be where the new stuff is going in.

 

[WorthFlorida]

Do not use a jackhammer, you do not know if there is rebar, though doubtful, and that kind of vibration near an exterior wall may cause cracks in the the walls and send cracks further through the floor. The rental store will have a concrete saw, as Terry suggested, and usually will cut through rebar or wire mesh. This would be a good job by getting help from your buddy's. It's a lot of digging, hauling concrete away and then carrying 60 or 80 lbs bags of premix to this level, then mixing and pouring. Do not go by what you see from the TV shows. They make it look like its a half hour job but there is an army of guys behind the camera waiting to finish the work. Just the cutting part can take a half a day, another day digging, a day or two laying pipe and then waiting for an inspection. How it is laid out you could be without a sewage connection for a day or two. The wife won't like that.

Depending on how far or how much of the drain system you need to replace, don't forget venting. If you are reusing the galvanized pipe for venting, when you cut the pipe at the p trap location you could have a lot of weight above from the iron pipe that is fairly heavy and it could drop some. It just something you have to watch.

It looks like you have a typical raised ranch built by the millions starting from the 1950's, and typically the plumbing was hung from this lower floor ceiling, then along the exterior walls to the exit point. Not being able to see the whole picture, your budget and skill set, it's hard to say the best way to go. If it was my home I would gut the entire lower level, hang the pipes above and later cover them in soffits if you want to have a finished off room. It will eliminate a lot of concrete work. Plumbing needs for the lower level you probably can still use the existing sump to pump up.

I'm trying not to discourage you, just to let you know its a lot of work, more planning than you may realize plus you still need to go to work, etc. It's not a weekend type job.

 

[Tuttles Revenge]

When I go to look at a remodel my rule of thumb for drain replacement is that 50's cast iron is fine.. All horizontal galvanized is trash. Vertical galvanized is sometimes OK but generally undersized. Most cast vents and galvanized vents are fine. There are exceptions. A camera inspection of your drains might save you a ton of work.

If your drains are shot and you must break up the concrete and you don't really care too much about the look of the floor surface because it doesn't matter or its getting covered by tile/laminate/etc then jackhammering is not bad for 70-100sq/ft. 50's concrete floors probably have little to no reinforcement and you can cut that with a sawzall or angle grinder. The slab would have been poured inside of the foundation so its not really connected and won't cause cracking to the foundation.. Everything in the house is going to vibrate so watch any paintings or vases on shelves. Absolute easiest is to hire a saw cutter to cut and remove the slab or save some cash jack the pieces out as Sylvan suggested. You may even get lucky and find that the slab is only a couple inches thick. I always run a 10" roto hammer bit thru the slab in at least 3 spots to guage its average thickness, at least once close to the perimeter in case of thicker pour at that point.

Repairing/repouring a jackhammered slab to finish it nicer.. Snap a chalk line and clear paint over it on the average jagged edge getting rid of 80% or more of the valleys. Then take a diamond saw in a worm drive saw with a helper keeping it wet. Cut down maybe an inch and bust that off with a hammer and chisel. The repour will be easier to get the concrete to flow into those edges.