View Full Version : Need help installing toilet in basement.
01-17-2012, 10:17 PM
I have a 1972 built home that has cast iron drain pipes. there is already a rough in for a toilet. it is a cast iron hub on a 4" pipe. The hub measures around 5" across on the inside. the top edge of the hub is actually 1 1/2 inches below the concrete floor. I tried to use a Fernco multi-tite gasket (donut) and a piece of 4" schedule 40 PVC to give myself a pipe to put a flange onto. The gasket fit into the hub fine, and the gasket would fit onto the 4" pvc fine, but when the gasket was in the hub I could not get the pipe to go into the gasket. I beveled the edge of the pipe and used half a bottle of dishsoap to no avial. I then tried to put pipe in hub first and then drive the gasket into space between hub and pipe, but it only went down a short ways and stopped. I thought it would work so I glued flange to pipe and glued flange to concrete floor with some polyurthane construction adhesive (more on that later) Waited 24 hours and pryed on toilet flange to see how tight it was and I pulled flange up along with the pipe. So, glueing flange down and the way the fernco was half-assed installed didn't work. So, first question is what should I do?
The other problem is that this hub which has a 5 1/2 outside diameter is surrounded by a another pipe. It looks like when they were pouring the concrete for the floor they put a steel pipe over top of the flange to keep concrete off of it. So the problem this creates is there is no way to screw the toilet flange down. There's only a part of the very outside of flange ring that rests on conrete. So, second question is how should I flasten the flange down when I have nothing to screw it too?
01-18-2012, 12:54 AM
Petrie, let me start be saying that, yes this is a site to get help on DIY plumbing jobs, and to your credit, you have asked for help before getting into trouble. That said, sometimes the best advise we can give a DIY is to hire a plumber. This will not be a difficult job for him, he has to know how, and the tools to do set your flange right. That last thing you want is a makeshift job on a toilet drain that causes problems. Forget about the adhesive and other gluing PVC to cast iron, etc.. I do realize that you and I look to DIY as a means to save some money and there's nothing wrong with that. But, there are times to be frugal and there are time to pay the man. I do believe this is time to pay the man.
01-18-2012, 05:17 AM
Caulk a piece of 4" PVC into the hub using oakum and lead wool. Then fill the void around the PVC with concrete, let it set then install your flange and fasten it down.
Do a "permanent" job and have a plumber install a stub of cast iron pipe with a cast iron flange.
01-18-2012, 06:19 AM
What's not permanent about caulking in PVC? If the hub is only 1-1/2" below the floor he wouldn't have enough pipe to fasten a cast iron flange to.
PVC is plastic. It will indent when the lead wool is hammered down, assuming he can calk it good enough to compress it into a water tight mass. If he has room for a PVC flange, he has room for a 4x2 closet collar.
01-18-2012, 07:27 AM
The PVC flange would go into the pipe. The cast iron flange has to go over it. And I don't see your point about the lead wool indenting the pipe. Besides the oakum is what seals the joint. The main purpose of the lead wool or poured lead is to hold the oakum in place. I was under the impression that main purpose of this forum is to help the DIYs. I gave him a solution to his problem that he can handle and will last longer then you or I will. If all were going to do is tell him to hire a plumber there would be no need for this forum he could just open the phone book.
01-18-2012, 09:48 PM
Here's some photos of the hub. The bottom shoulder of the hub is 4 1/2 inches below the finished floor. So, I'd definetly need a piece of pipe with a flange on it, not just a flange. If I hired a plumber what would he most likely do? Would he put a cast iron stub in useing lead and oakum? How would he fasten the flange to the floor...does a cast iron flange need to be fastened to the floor or is it strong enough joint where it doesn't need to be? Somebody at work told me I should just fasten a piece of 3/4 plywood to the floor for the toilet to set on and I could screw the flange to that just like one would do if it was going on floor decking on the upstairs toilet. They suggested I could then trim around the plywood so it looked nice under the toilet... maybe trim it out.
I considered pouring concrete around the pipe to give me something to screw the flange to, but being as the hub is sourounded by a piece of 6" snap together stove pipe I'm not sure if I'd just end up with a concrete plug that wasn't bonded to the rest of the floor.
01-18-2012, 10:35 PM
Somebody at work told me I should just fasten a piece of 3/4 plywood to the floor for the toilet to set on and I could screw the flange to that just like one would do if it was going on floor decking on the upstairs toilet. They suggested I could then trim around the plywood so it looked nice under the toilet... maybe trim it out.
Yes the flange needs to be fastened to the floor. There are lots of methods for anchoring into concrete...
You probably shouldn't solicit any more advice from your friend at work though...
If you're going to fasten anything to the floor, it will be the flange itself, not a piece of wood...
What terrible advice.
01-18-2012, 11:07 PM
Lets say I can get the Fernco multi-tite (donut) into the flange with the 4" pvc pipe in it and everything looks good. can I then fill the hole with concrete flush to the floor and pipe and then put a flange on and screw it to the concrete with masonary screws? Is this an acceptable installation? I could probably undercut the concrete around the flange a little more so that the concrete I poured would be under part of the floor slab. part of the floor slab hangs a little over the hole already.
In the picture above where I have the writing around the hole the screws for the flange end up being right on the edge of the concrete. So, I can't ancor it to the concrete with screws. That's why I tried the Polyurthane construction adhesive.
01-19-2012, 05:04 PM
By far the strongest connection would be a poured lead joint. But, as you've found, getting the pipe and donut into a hub can be a challenge. If you go to the Fernco website, you'll find numerous donuts in incremental sizes. Not all CI hubs are created equal, so they make various donuts to fit - there is NO one-size-fits all. They're available in small incremental size variations so that you can actually insert the thing and provide the proper compression seal. Now, what you have may fit, but you may need a block of wood and a sledge to get it installed. If you measure the ID of the hub, you can look up what size donut you need. You may need to order it, but if it is different than what you have, that's why it doesn't want to go in.
01-19-2012, 07:09 PM
There are all sorts of ways to DIY this, but all of them are makeshift at best. You seem determined to save money by not hiring a professional and hack something that may work. You may or may not succeed. Good luck.
01-19-2012, 07:46 PM
In case anybody was wondering, Gary thinks this guy should hire a pro.