waste pipe not vertical = toilet flange not level

Home Forums Public Forums General Plumbing waste pipe not vertical = toilet flange not level

Viewing 3 reply threads
  • Author
    • #276978
      Avatar photocraig stout

        I am installing a toilet in my basement. I paid the builder for the “rough in”. It turns out that the waste pipe was not perfectly vertical when they poured the concrete. With the pipe cut flush with the vinyl floor, the back of the flange is up by 1/2 inch. This means the back of the toilet is up by 1/2 inch. The builder suggested that I either shim the flange and toilet, or, chisel the concrete below the front of the flange until the back of the flange is lowered. Is this good advice?

        I can’t live with the back of the toilet up 1/2 inch. If I chisel the concrete, the toilet will sit level, but I have to imagine that I am affecting the seal on the front side of the flange. Any suggestions?

        John Winchester

        P.S. I am very surprised that I have not seen this problem listed on the web sites that I have checked. I can’t believe that every waste pipe was installed perfectly vertical. The “toilet installation” articles say that the flange should be flush with the floor. They don’t say what to do when it’s not.

      • #295170
        Avatar photoDUNBAR

          Sounds like the builder wants you to pay for his mistake.

          I would demand he come back and fix it before you pay a plumber and send him the bill. That is ridiculous to have a pipe that far out of level.

          The correct way to fix that problem is to bust up the floor and turn a LEVEL pipe out of floor and then proceed to set flange.

          Nothing worse that people installing plumbing wrong for others to find.

        • #295171
          Avatar photonicktheplumber

            I agree with Dunbar that your builder $%&#ed up and should fix it. I’m not sure how your builder works, but in my area it is usually a plumbing subcontractor who lays out the pipe runs. When I lay out the under-slab DVW pipe, I make sure the runs are as they should be according to the plans and that the risers and stub-outs are vertical. I assume your problem is really due to non-vertical risers and not due to some unlevel concrete placement.

            For what it’s worth, I have had to fix the kind of problem you describe, i.e. a non-vertical riser and skewed toilet flange (not originally placed by me…I don’t make that kind of mistake). The way to fix that mistake is to cut the riser below the slab (an internal pipe cutter works well) and then to insert a new flange that rests properly on the slab. It’s a relatively simple job for someone equiped with the right tools, but it might be an expensive and pain-in-the-ass task for a DIYer.


          • #295172
            Avatar photojohnwwin

              Nick and Dunbar… thanks for the info. I’m racing to get this done prior to the arrival of house guests, so, I’m not sure that fighting with my builder is the best option.

              I’m not sure how cutting the pipe below the slab will change the angle of the flange. The flange that I have now slips into, and is glued to the 4 inch pipe…it will remain perpendicular to the non-vertical pipe. I’m guessing that there are different flange setups that I should look into. In my mind, there should be a flange available with an angle offset…I haven’t found anything like that…just lateral offsets.
              John Winchester

          Viewing 3 reply threads
          • You must be logged in to reply to this topic.

          Pin It on Pinterest

          Share This