cutting hole for toilet pipe

[econguy]

hi

i'm doing some remodeling work, and my plumber just cut a hole for the toilet flange. right now, i only have 3/4" OSB subfloor, plus 1/2" plywood underlayment. i plan on putting down ditra and tile. the flange won't be installed until the end, right now the pipe is just a long stub-out that will be cut down.

the hole he cut is a little too big, in that the perimeter of the flange will be supported, but the screws won't have anything to bite into.

i have access from the basement. can i cut a patch of plywood, and screw it to the bottom of the OSB? i figured he could use some longer flange screws to screw into the patch.

thanks

[jadnashua]

Yes...he should know better, though.

[iminaquagmire]

I had a similar situation in where the top layer was cut to the size of the flange and the bottom layer a little smaller. I put expanding foam in around the pipe and trimmed it flush with the first layer. Then I put hydraulic cement in flush with the tile, then drilled that and put masonry anchors and stainless screws in to hold the flange in place.

[Cookie]

This is what happened to me, the hole was cut out too big and the toilet screws doesn't bite into anything.

If I could go back, I would insist that part of the floor be redone until, it fits right. He fixed mine by laying 1/25 inch Louann board over it that fits nice but, the toilet leaks because the screws dangle right through the board. I can see it from the access panel. The louann board is now warping and the toilet rocks, and it leaks and leaks and leaks.

I simply gave up.

[Dunbar Plumbing]

Take pictures.....this we gotta see.