New Toilet Flange, Stone Slab Floor

Discussion in 'Toilet Forum discussions' started by zmonk, Dec 10, 2012.

  1. zmonk

    zmonk New Member

    Messages:
    6
    Location:
    Hastings on Hudson, NY
    Hi. I'm hoping somebody has encountered this situation and may have a suggestion.

    The floor in our 2nd floor bath is a mashup. Most is 3/4" plywood, with some concrete sections around the borders. The toilet sits on a slab of some sort of stone -- slate or bluestone perhaps. It does flake. As you can see, the old flange has been removed from the drain pipe, which appears to be made of lead -- it's very soft. The pipe is not centered in the hole that has been cut in the stone, and it cannot be moved.

    The stone slab is about 3/4" thick, and cut on an angle that increases the interior diameter from top to bottom. In other words, if the diameter of the hole on top of the slab is 5 inches, it flares out to a larger interior diameter at the bottom of the slab. It appears to be resting on the floor joists, so there is air underneath it.

    A compression flange that fits around the exterior of the pipe does not appear to be an option. I could chip away enough of the slab so that it could fit around the pipe, but then it has nothing to sit on. My only option seems to be a pvc Sioux Chief flange with a metal reinforcement ring that fits the interior of the pipe and seals with a 3-ring rubber flange.

    I would like to fasten the flange to the stone slab at three points, taking into account the fact that at least one of the fastening points will be close to the edge of the stone, so I need to cut clean holes in the slab, without destroying it. Then I would use toggle bolts to tighten down the flange. (By the way, the floor will be finished with 1/4" backer board and 1/8" ceramic tiles, all secured with modified thinset.)

    Is there a tool that can give me a clean hole through the slab? If not, does anybody have an alternative solution? Thanks in advance.

    Howard

    Attached Files:

  2. BobL43

    BobL43 DIY Senior Member

    Messages:
    1,786
    Location:
    Long Island, NY
    Last edited: Dec 10, 2012
  3. cacher_chick

    cacher_chick Test, Don't Guess!

    Messages:
    3,236
    Location:
    Land of Cheese
    If you have a lead closet bend, NO ABS or PVC flange is going to seal to it. This needs to be done right, or you are going to have a leak. Without seeing what is there, it is impossible to say what needs to be done.
  4. zmonk

    zmonk New Member

    Messages:
    6
    Location:
    Hastings on Hudson, NY
    I guess the proper solution would be to extend the drain with some sort of collar and then lead caulk a new brass flange at floor level. Unfortunately, that's beyond my skill level. Here's the unit I plan to install

    http://www.siouxchief.com/Drainage/ResidentialDrainage/Closet-Flanges/Push-Tite.VZ8US

    The 3-rib gasket fits very snugly; the plastic down pipe can be trimmed to accomodate the bend. And, yes, the diamond tip hole saw looks like a winner. I found one at the local tool rental in 5/8". I'm just hoping the slab does not shatter drilling so close to the edge and that the plastic flange holds up under daily use. I have read posts on the web from others who have used non-metal flanges successfully . . .
  5. jadnashua

    jadnashua Retired Defense Industry Engineer xxx

    Messages:
    21,809
    Location:
    New England
    If you want to do this right, you need to tear more out than you're currently planning. CBU is not specified for use over cement (or stone) - it is designed to be screwed down to plywood. It MUST have a layer of thinset underneath it as well. The purpose of that thinset is not to anchor it, but to fill any imperfections and provide 100% support to the floor tile above. In addition, it provides a compatible surface for the mortar to hold the tile down.

    Way back when, places required a stone piece underneath the toilet to help ensure it didn't fall through the rotten wood if the silly thing leaked (and lead was more prone to that than modern equivalents).

    You have not indicated if you evaluated the floor for proper strength (deflection ratings) to determine if it could even support tile properly.

    With your mix of wood and concrete, old leaded pipes, and who knows what, you are at big risks for a successful remodel!

    None of the expansion toilet flanges are designed to work in a leaded pipe. The lead is highly unlikely to be nice and round, and getting a proper seal is very unlikely.

    If you don't want to be redoing this shortly, you need to rethink what's going on and how best to do it right.
  6. zmonk

    zmonk New Member

    Messages:
    6
    Location:
    Hastings on Hudson, NY
    Okay. First of all, thanks for the input. But this is not an expansion flange, just a passive triple gasket seal. Granted, it may not last forever (what does?), but I don't have a lot of options at this point. The floor had ceramic tiles previously, which I removed, so no issue there. The backerboard will be fixed to the floor materials with modified thinset and a combination of ribbed waferhead screws (as per manufacturer's instructions) in the plywood sections and coated tapcon screws in the concrete and stone sections. Which brings me to the point of this post.

    I was all set to spring for the 5/8" diamond tip hole saw, but decided to mark the drill locations in the stone first, so I could see how close to the edge of the opening the holes would come. Nothing I had was leaving a decent mark on the stone, so I decided to use a conventional drill bit, just to make a scratch. That's when I discovered that the slab is made of a very soft stone, easily drilled out and capable of holding a tapcon concrete screw securely. I figure I'll drill pilot holes (5/32" I believe) and sink four or five of them through the tile, thinset, and backerboard, deep into the stone slab. That ought to hold the flange tight and flush with the tiles for as long as the plastic and the gasket will last. And if it dies before I do, it'll be easy to replace.

    Any ideas as to what type of stone this might be? Dark blue/gray in color, very soft and powdery when you drill into it . . .
  7. Gary Swart

    Gary Swart In the Trades

    Messages:
    7,302
    Location:
    Yakima WA
    This is a DIY forum, but sometimes the best advice is to hire a professional. I believe this is one of those times. There is NO quick, easy fix for what you have, and there are skill required to do the job right that you do not possess. That's pretty blunt I know, but we all have our limitations. We just need to know when it's time to admit them.
  8. cacher_chick

    cacher_chick Test, Don't Guess!

    Messages:
    3,236
    Location:
    Land of Cheese
    One of the things you are overlooking is that this has to be an airtight seal or sewer gas is coming back into the house. The standard test requires the system to prove tight under a pressure of 5 psi or a 10 foot head of water.

    In the end you can do whatever you want, but it is beyond me why you would want to take a chance when you are planning to re-do the floor anyway. Tear it out, fix it right, and you will never have to think about it again.
  9. zmonk

    zmonk New Member

    Messages:
    6
    Location:
    Hastings on Hudson, NY
    Thank you Mr Swart. But can you be a little more specific? What is the reasoning behind your assessment of the situation?
  10. Terry

    Terry Administrator Staff Member

    Messages:
    14,770
    Location:
    Bothell, Washington
    Normally you would have enough lead to work with. You are kind of short there. Like someone broke off what was needed.
    Is there a way you can work from the lower floor, to remove the lead bend and install new pipe?

    The fitting you are thinking of is not designed for use in lead.
    Anything "can" be done. Not everything works well though.

    http://www.terrylove.com/forums/showthread.php?6980-should-I-replace-the-lead-bend
    Last edited: Dec 10, 2012
  11. zmonk

    zmonk New Member

    Messages:
    6
    Location:
    Hastings on Hudson, NY
    You're right, Terry. I removed the old brass flange because it was damaged on one side and flush on the stone slab. I need to add the backerboard, thinset, and tile. I might have been able to use a flange repair kit, extenders and/or an extra deep wax donut, but that's water under the bridge (or down the drain) at this point.

    I'd like to avoid working from the lower floor, if possible. I could probably remove the slab and work from the top down, but it appears from the link that I would have to cut out the lead bend and install a plastic one. There would be a bit of a learning curve involved. And I'd end up with a plastic toilet flange in the end regardless.

    Are you sure about the flange insert being not compatible with lead? It seems to fit pretty snug and secure in the old pipe.

    Thanks for your time and advice.
  12. meselffff

    meselffff New Member

    Messages:
    11
    Location:
    Wisconsin
    >> "Is there a tool that can give me a clean hole through the slab? "
    << You might try a 4" angle grinder with a concrete wheel on it. Stuffing wet rags against the nearby area and keeping them wet might be a good idea to prevent overheating, which can cause some stone products to crack when they're being cut or ground.

    OOPS! I should have focused on your question better. The angle grinder won't cut holes for the toggle bolts. Won't a carbide masonary drill bit cut the holes in the stone? Maybe a Dremel with a $15 straight 1/8" carbide bit if you have to. I usually place the toilet flange on top of the backer board, after making sure that the mortar is well filled around the edges of the hole under the backer board. It tends to give me a flange height just a tad lower than the tile when working with 1/4" tile and a 1/4" x 3/8" notched trowel. So I would think the flange might be at least level with the tile floor but hopefully not high if you're using 1/8" tile with the flange on top of the backer board and enough mortar, right? Flanges that protrude much above the tile floor tend to be problematic because it causes the toilet to rock, ruining the wax seal. So installing a flange on top of tile is probably not good policy. My quick cheater fix when I encountered a rocking toilet because the flange was too high was to replace the wax ring, clean the bottom edge of the toilet, and use sanded enhanced grout under edge of the toilet on top of wax paper so the toilet didn't get bonded to the floor. Then cut and tear away the excess wax paper after the mortar started to set. OK I cheated but at least I didn't cause the problem in the first place and I can't justify re-doing the flange and possibly the floor when this cheater fix seems to work so well. We all just have enough honest work without running up somebody's bill unnecessarily, right?
    Last edited: Dec 20, 2012
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