Flange dilemma

[Kevz]

I am debating now if I should have a plumber come in and do a lead connection new cast iron flange to my cast iron pipe.. Or if I should use one of the compression seal flanges and screw into the subfloor.

Wouldn't mind saving a few bucks.

Any reason not to use these? The floor will be tile laid on cement board, the subfloor under that is 2 layers of ply for a total of 1 1/8". I could also add additional backing under the floor very easy for more wood to screw into.

My only question is about the size of the hole. The subfloor right now is cut out around the pipe with some space. On one side there is probably almost 3/4" gap between the pipe and the plywood, is that too much? I guess I could always add backing from the underside and fill the gap and screw into it all?

Any advice would be appreciated, going back and forth over this.

Thanks

 

[Plumber1]

flange

There are ways, but I believe only one right way to do this job.
I can trust a cast iron flange and a lead joint.
Your connection is rock solid to the drain.
I've see em all and I think it's Mickey Mouse to trust wood screws around a toilet connection.
If you haven't yet, break off the old flange and re-lead a new deeper flange on to that toilet stub. With thicker floor , you will need a deeper flange.
It will make a much better job.
It would be money well spent.

 

[Sponsor]

 

[bigrebnc1861]

I do commerical plumbing for a living, and if we use cast iron pipe we use no hub bands, and the compression pvc closet flange and the do work like a charm. In a residental setting it should work nicely for you.

 

[Kevz]

If I can easily, I think I would like to give the compression flange a chance. This bathroom will not even be used often, extra half bath off a laundry room.

Only question is how much space is there from the outside edge of the stack and where the screws go into the subfloor? I might need to add some blocking from the underside if the hole is cut too big right now.

Also, I am assuming you would want the cast iron pipe to be flush or under the finished floor? Looks like I would need to chip away some of the cast iron pipe. No more than 1/4" on 1 side of it.. Is that hard or risky?

Thanks

 

[Jadnashua]

Cast iron is brittle, so yes, you could end up taking a chunk out. My unprofessional opinion. Saws are a big pain as they don't cut the stuff well, although a sawzall will do it. A grinder would work, too, but depending on how much, could be quite slow. One of the pros will have some ideas, but knowing how much thatneeds to be taken off will affect their thoughts, too. A picture?

 

[Gary Swart]

Recip saws are not too good for this. A grinder would work, BUT they can hurt you big time. They tend to bind in the kurf and they are so powerful you can end with a broken wrist before you know what happened. I'd strongly recommend hiring a plumber to do this job. Not only will it be done right, you'll still be in one piece. I could show you a couple of scars on my wrist from just such and adventure! I was lucky and had no broken bones.

 

[Kevz]

Cast iron is brittle, so yes, you could end up taking a chunk out. My unprofessional opinion. Saws are a big pain as they don't cut the stuff well, although a sawzall will do it. A grinder would work, too, but depending on how much, could be quite slow. One of the pros will have some ideas, but knowing how much thatneeds to be taken off will affect their thoughts, too. A picture?

Here is the picture of the pipe.. I will not have much at all to remove. That backerboard isn't installed yet. Once that is installed with thinset under it, and thinset under the tile I think I may only have a just a hair to take off on 1 side on a few of the high spots that you can see in the picture. Could probably grind them down fairly easy since they are points and only need to take them down a little bit.

My only concern was the opening for the pipe(can see in 2nd picture), thought it might be too large on the one side. That is a joist on the bottom part of the picture. I could from the underside use some backing so when I screw down even if I wasn't going into the subfloor there it would pull tight though, and just add some filler so it doesn't break. Assuming that would work and be just as good?

 

[Plumber1]

flange

You really have a run of the mill job.

I would use a 3' deep closet flange and lead and oakum.
Your pics. show very well that this is very easy to do.

Chew out enough of the joist so your flange will center on the stub.

Finish your floor job then set the flange on the hole.
Lead it on and cork the lead nice and tight.

It may not be but if there are some places too high, just NIP those ridges with a hammer from the inside of the stub. A little above the flange can be ok.
Check it by setting the bowl on the hole. You will know.......

If you do this, you will have done the right thing. No blocks or screws
And you will be more satisfied..........

 

[Lakee911]

If you're concerned about the gap on the edges, why not cut a 12"x12"piece of plywood that fits better over the pipe and motar and screw that down in place of the concrete backer board underneith the toilet. Then attach your flange of choice w/ stainless screws.

my three cents

Jason

 

[Kevz]

If you're concerned about the gap on the edges, why not cut a 12"x12"piece of plywood that fits better over the pipe and motar and screw that down in place of the concrete backer board underneith the toilet. Then attach your flange of choice w/ stainless screws.

my three cents

Jason

The backer board is only 1/4", which would be pointless for holding screws. If I don't lead it I don't see a reason adding wood from the underside to screw into which would pull it tight against the whole subfloor wouldn't work. Guess I just deice if I want to do that and install it or hire someone to do the lead. I don't really want to take that on myself.

 

[Kevz]

Ok, pretty sure I will be just using one and securing it to the subfloor. Went and picked up 2 different ones to see if either lined up better with what I thought was an oversized hole in the subfloor, turns out it looks like both would catch a pretty decent amount of the subfloor. Still will most likely beef it up a little from the undersize just to be extra safe.

Just wondering if there is an overwhelming consensus on which type is better. On the left goes outside the pipe with and has set screws to compress around it, the right just slips in the 4" pipe and is then screwed to the floor. Slipping inside the pipe seems less likely to ever leak, it also has more screw holes to secure it to the subfloor.

With either, what type/length of screws do you guys use with these?

Thanks so much for your help.

 

[Cal]

Use the one on the right,,they work great ! Secure it to the floor with some good exterior screws and GO !!