oddness in toilet mounting plate

[Frank Fodor]

Let's try this here, as the unmoderated home repair forum sites are pretty clueless, and mostly aren't even about home repair anymore.

We just had a wobbly toilet in a 1960s-era house. I think I last got under it a decade or two ago to reseal it with wax. I figured the mounting screws just needed tightening this time. But no, they were tight. So what the #$%^&?

I removed the toilet and found that the closet flange, which the toilet was securely anchored to, had split off from the lead (as in, not steel) tube that was wedged into the 4-inch drain. That tube was about 6-inches long, so once securely wedged in the drain, the attached flange didn't need to be screwed to the floor to be secure. Well, as long as it was attached, which it was no longer.


So, OK, this is a heavy steel flange that had been somehow (soldered?) connected to this lead tube. The tube walls were pretty thick. About an eight of an inch. The flange just broke clean off from the tube. Now unfortunately that left the lead tube stuck in the drain. I figured I could bend/pry it out, but it wouldn't budge. I ended up totally mangling the lead tube with a screwdriver, whacking it down the sides, and laboriously pulling chunks out. I'm guessing adhesive was used. Took more than an hour of mangling, but I finally got the full ID of my 4-inch pipe back. So I then installed a new PVC closet flange, and anchored that to the floor.


But really, a closet flange attached to a heavy lead pipe glued into the drain?? Has anyone seen a toilet mounted in that way? How might that pipe be more easily removed from the drain?

[Nestor]

Frank:

From what you're describing, you had a "lead bend", which are very common where I live. In a true lead bend installation, the lead will rise up through a brass floor ring which will be screwed to the floor. The plumber will then simply pound on the inside of that 4 inch lead pipe sticking up through the floor ring while heating it with a torch and in that way bend the lead over the brass floor ring. That floor ring will have slots in it for floor-to-bowl bolts. The other end of the lead bend is more complicated. A large brass ferrule will be installed in the hub of a 4 inch cast iron pipe with oakum (or nowadays PC4). Then, the other end of the lead bend will be soldered to that brass ferrule with a "wiped joint". That's where a plumber wearing a wet leather mitt melts solder onto the joint and then spreads the solder over the joint with that wet mitt so as not to burn his hands. Normally, they would connect the lead bend to the cast iron hub before pounding the lead down over the brass floor ring.

But, from what you're describing, you had a lead pipe "glued" or something into a cast iron pipe, and the top of that lead pipe was finished much the same way as a normal lead bend.

In any event, a more diplomatic way of dealing with that situation would have been to use an Oatey Twist & Set floor flange, shown below:


This kind of floor flange has a tapered plastic thread on the bottom of it. A rubber collar that screws on to it has a matching tapered thread so that as you screw the rubber collar further and further up the floor flange, it's diameter increases. And, of course, there's a liberal amount of grease on the threads so that tightening the thing up is actually easier than you probably imagine. So, basically, you just screw it up until you can just barely fit it into your lead or cast iron pipe, then press it down flat onto the floor, twist it kinda cockeyed so the rubber collar grabs the ID of the pipe and then continue turning to tighten the collar snug against the ID of the pipe until it's snug and one pair of slots for your floor-to-bowl bolts are in the right position to install the toilet.

These Twist & Set floor flanges are available in both 3" and 4" sizes. The 4 inch flanges cost about $25 and they're very popular with the plumbers where I live.

[HayZee518]

old house drains

real old house drains [circa 1950's] all used lead drains. a fitting called a DeSanko fitting is used to mate the lead with the slip joint hardware for waste lines. It is wipe-soldered onto the lead pipe. As far as the toilet waste line, closet flanges were made of metal, not primed and certainly not galvanized so any leakage would eat away at it. Eventually they fail as you witnessed. option one and the most expensive is to replace the entire waste line with 4" pvc to the stack, which is cast iron. the other option is to remove as much of the flange material as you can and purchase a flange adapter. this is a galvanized metal ring that hinges at one point. you place it under the lead and hammer the lead on top of it. the flange is screwed into the sub floor wood. the closet bolts come up at the nine o'clock and three o'clock position so you can fasten the toilet base to the flange. the wax ring with or without the reducing fitting provides the flange to pot seal.

[Frank Fodor]

These are useful comments. Thanks.

Nestor, the pipe coming up in the floor (slab) isn't lead. It seems to be something more solid, presumably cast iron. The lead tube (which was once attached to the closet flange) looks like it was just shoved into that 4-inch pipe, with a tight fit. As I said, it didn't want to come free on it's own, so I have to suspect adhesives.

I considered the Oatey Twist & Set, but it wasn't obvious to me that it would expand to the right diameter for a tight fit. In retrospect, I should have realized that it would. So I ended up just using a PVC closet flange that had a 3-inch length of 4-inch PVC tube underneath. Worked OK.

HayZee, that sounds like what I have. Indeed, the closet flange was pretty well corroded. But the cast iron drain pipe comes up flush to the floor, so it didn't really need to be replaced. I just needed to scrape the lead liner out of the inside so I had the original full 4-inch ID.

I am pretty surprised that such a predictably failure-prone method was used for this. OK, so the closet flange is going to corrode away. But then it leaves behind a nearly unextractable lead sleeve? Dumb and dumber.

Actually, toilets in general are pretty archaic engineering. The idea of using a big hunk of soft wax to make a seal is a concept that should have gone out with the Model Ts.

Because the flange and lead sleeve ended up being broken, the seal to the drain pipe was compromised, and it looks like I had water seeping along the slab under the floor tile to the wall a foot away. So the wallpaper at the base of that wall is moist and starting to rot away. Before I found this broken flange, I figured it had to be a leak in the ceiling, but I could never find it!

[Nestor]

If there is a next time, try the Twist & Set.

I have also used an ABS floor flange with a foot long (or so) piece of 3 inch ID ABS pipe cemented into it to repair a damaged lead bend. It works, but the Twist & Set works better in my view.

One of the advantages of the Twist & Set is that you can remove it. When I put an ABS floor flange onto a lead bend, I clean out the inside of the lead pipe and schmear silicone all over the ID of the lead pipe and the underside of the floor flange. That kinda glues them together, and it makes it hard to remove the ABS floor flange from the lead bend should you want to replace it with a Twist & Set.

Anyway, now you know how else this job coulda been done.

[HayZee518]

toilet flange

most of the time the vent stack is in a corner or slightly out from a corner. the bottom goes all the way down to the basement and waste line to the street. the opposite end goes up through the roof to vent out sewer gasses. at a first or second floor is a waste fitting called an eighth bend and a sanitary cast iron T. sometimes this fitting is a wye with the eighth bend and a 45 degree bend. the toilet flange is made up to the 45 bend with oakum and poured lead, the "caulked" into place. caulking means the soft lead is pounded into the joint with a bent chisel and a hammer. when waste water enters the joint, oakum expands, sealing the joint. because of the close proximity of the flange and bend, the joint is made up first then the whole assembly is inserted into the eighth bend AND leaded there.

[Frank Fodor]

If there is a next time, try the Twist & Set.
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Anyway, now you know how else this job coulda been done.

Point noted. Although I don't think the Twist & Set could have fit inside the lead tube. That tube left the ID of the pipe flange only about 3.75-inches in diameter. You can't do anything useful with that clearance. The largest part of the job, as I said, was extracting that lead. But once I removed the lead tube, Twist & Set might have been the right way to go.

Now, another advantage of the Twist & Set, I gather, is that once tightened down, it doesn't rock back and forth. So bolting it to the slab (I used expansion posts to do that for the PVC fixture I used) would not have been necessary, maybe? That would have made life a little simpler.

[Nestor]

I just happen to have a 4 inch Twist & Set in my grubby little hands, and the smallest diameter it unscrews to is 3.75 inches. At that point, the rubber collar is entirely over the tapered thread at the bottom of the floor flange. As you tighten it from there, it expands out to about 4 inches.

EVERY floor flange that isn't securely screwed or bolted to the floor will potentially result in a wobbly toilet, including the Twist & Set. However, may toilets have "front" holes that don't attach to the floor flange that will hold the toilet steady even if the floor flange isn't secured to the floor. That is, there will be 4 holes for mounting the toilet; two in front and two in back. If for some reason you can't fasten the floor flange to the floor, you can simply bolt the floor flange to the toilet bowl and rely on the front bolts to hold the toilet steady. Better to have the toilet secured to the floor in both front and back tho.

If there is a next time, use a Twist & Set. You don't necessarily have to use the bolt holes in the Twist & Set. If construction adhesive will stick to PVC, you can simply glue the Twist & Set in place by caulking around it with a construction adhesive. If you ever want to remove it, then you end up wrecking a cheap $10 Stanley wood chisel cutting the old Twist & Set out and caulking a new one in with construction adhesive. That'll be strong enough (after curing) to hold the toilet securely in place.

[Frank Fodor]

Yep. OK, let me stop banging my head against the wall. It looks at if the Twist & Set might have fit without removing the lead!!! I just looked at them in the store without measuring them, and assumed they were probably just under 4-inch, and wouldn't fit. Would have been smart to measure them.

Good point about bolting to the the floor. Now this toilet does happen to have a pair of anchor holes in the front, though the screws under those holes rusted out, leaving holes in the slab filled with screw shank. I thought hard about whether to try to drill those holes out and put expansion posts in there, but finally decided not to. Since the closet flange is now securely bolted, I don't really need those front screws anyway.

[Nestor]

Never ever never use ordinary steel in any plumbing application where it could get wet periodically; even wet from condensation forming on it. When it rusts, it's just going to create problems for you.

Either solid brass or stainless steel.

Nothing else will do.

If the floor flange is firmly secured, then you can normally do without those front toilet mounting bolts.

[Frank Fodor]

Never ever never use ordinary steel in any plumbing application where it could get wet periodically; even wet from condensation forming on it. When it rusts, it's just going to create problems for you.

Either solid brass or stainless steel.

Nothing else will do.

Well said. That's not just for the flange, but for those front anchor screws as well. When they rust out, there is no easy way to extract the remnants from their holes, and those holes, being directly under the mounting clearance holes in the toilet, are the only places you can put new ones in.