Lead, Oakum and PVC

[DerbyDad03]

I learned something new yesterday.

I never knew that you could use lead and oakum with PVC pipe. On Ask this Old House they were attaching a new PVC drain pipe to the existing cast iron where it went through the foundation. They cleaned out the old lead and oakum, inserted the PVC fitting, stuffed in the oakum and poured in the lead. They said they had to wait at least a half hour for the PVC to cool before continuing the work.

I assume the softening and then hardening of the PVC is what gives the lead the bite it needs to hold.

[philoÂÂ]

There are fittings made for exactly that purpose, I doubt it's even legal to use lead in plumbing anymore.

[trader4]

Given that it was shown on TOH, I bet you're wrong that it's not code compliant. I agree it sounds weird, but from what I've seen on that show, they never violate code or take a quick, unsound fix.

As to fittings made for that purpose, I can invison a female elbow, whatever, emerging at the level of a concrete floor, where the outlined app roach would work and where it would be a bitch to tear it all out and put in a Fernco. Not even sure that's better, because then you have a Fernco buried under concrete. The way they did it, if something leaks, you'll see it.

[Dan Espen]

This was a waste pipe and with the oakum, I don't think there is any water/lead contact.

[philoÂÂ]

Ok, looks like it's legit.

[Stormin Mormon]

Did the molten lead touch the plastic? Sounds unsafe, to me.

[DerbyDad03]

BTW...it was TOH as you stated, not ATOH, as I originally stated.

Almost what they were dealing with except the female fitting came out of the stone foundation up about 3' from the floor. Either way, it would have been a major PITA to get to use a Fernco in this situation.

Probably not. The reason why they were replacing the old cast iron drain was because it hung down from the ceiling in a an area of the basement that they are finishing. All of the new pipes will be hidden behind finished walls.

[DerbyDad03]

How would it not?

Why?

[Stormin Mormon]

If the oakum were set up as a dam. Hot lead, melt plastic. Light fire.

[HerHusband]

Code or not, I doubt many people have lead and oakum available these days, or the skill to use them. I know I wouldn't attempt something like that.

On TOH it looked like there was probably an inch of pipe behind the hub that was still sticking out of the concrete. If I was in that same situation, I would use a small angle grinder with a cutting wheel to cut off the hub. Then I would drill and/or chisel the concrete back enough that I could use a commonly available Fernco coupling on the iron pipe.

Of course, if you want the easy way of handling it, you could use a Fernco donut:

There's usually more than one way to get a job done...

Anthony Watson

[Ed Pawlowski]

No lead for the supply side, OK for the drains.

[gfretwell]

That surprises me. You can't even throw lead in a land fill in some states. The lead laws go far beyond what was posted about potable water pipe. When was the last time you saw leaded gas on the street? They are even trying to get it out of AvGas but changing anything on an airplane takes a lot of time. That is bureaucracy and myth , not science.

[DerbyDad03]

Watch the video here, starting around 19:30

There is no straight pipe exposed to attach a Fernco to. In addition (no pun intended) it's a rubble stone foundation. I doubt you could easily chisel the rock out to expose enough pipe for a Fernco.

That's what I used to upgrade the shower in my basement. The original "base" was the slab itself with a hole cut in it. A kitchen sink strainer was then dropped in the hole to prevent stuff from falling in. I jack hammered the floor, removed the cast iron back to the wye and use a Fernco donut to accept the PVC.

However, i don't know if Fernco makes a donut that is not also a reducer. You will note they lead in what appears to be a 4" pipe to keep the size consistent with the cast iron. I don't think you'd want to reduce the main drain down to anything less than 4". I don't know if you are even allowed to.

If Fernco makes a donut for that connection, I agree that that would work also.

Of course, getting it done right matters also.

[DerbyDad03]

That's how lead and oakum works. The oakum acts as a dam and gives the lead something to grab onto. If the lead didn't contact the PVC it wouldn't seal.

The lead is not hot enough to set the PVC on fire.

[trader4]

Certainly an interesting video. I wouldn't think lead would set the PVC on fire, but I would have thought it might melt it enough to damage it. But it obviously works.

[DerbyDad03]

Nit pickin', but I'm sure it does damage the PVC.

I'm sure that if you could see the PVC under the lead the exterior of the PVC would be "damaged". However, even if it damaged the interior surface a little by making it wavy, it would probably still be smoother than cast iron junctions, cast-to-PVC with a Fernco, etc.

The hint was that they had to wait a half hour before they could work with the PVC fitting. I'm guessing it was pretty soft for quite a while.

[Bill Gill]

Remember, this is a drain. There isn't enough pressure to blow out the pipe, even if it does lose a little strength.

Bill

[HerHusband]

It's hard to tell from the video, but it still looks like there's a little bit of pipe between the hub and wall. I didn't realize it was a stone foundation, but that probably means there's just mortar around the pipe which would be a lot easier to chisel out than concrete.

I don't know either, I have never needed to use one. All of the work I have done these days uses three inch PVC anyway, which slips inside 4" cast iron easily.

Anthony Watson