So I've been working on finished our basement, and am in process of putting the finishing touches on our bathroom. I have what I think is a 4 inch pvc drain for my toilet, and was hoping to install a 4 inch pvc inside flange on this drain pipe. The drain was cut off flush to the floor (none sticking out) and I recently tiled the floor of the bathroom. I purchased one 4 inch inside toilet flange at a big box store, and noticed the flange is slightly too small for the inside of the drain pipe. I thought, hmm, must be something wrong with this toilet flange, so I went to a competing big box store and purchased a different brand, 4 inch inside toilet flange, and the diameter of that flange as well wasn't tight inside the drain pipe. So, my my first question:

1. How is this drain pipe slightly larger than 4 inches, and what do I need to do to get this closet flange to fit tightly?

I was hoping to just seal the flange to the pipe with Oatey and not have to drill holes through my concrete or tile (just bolt toilet to flange), but I have feeling whatever the solution is, I'll have to drill holes to secure the flange to the floor. Does anyone have any good direction for me?

If I need to drill holes, I have a variable speed drill.

2. What type of bit and bolts do I need, and are there good procedures for drilling through slate without cracking it?

Is it 4" pipe? Is it pvc or is it abs black pipe? If it is black pipe, use the compression flange with the 3 allen screws. No drilling.

The closet ring that fits inside pipe is a specialty item that not all Big Box Stores carry it. Go back and be more careful which one you select.

Don't worry, if you have PVC and ring is ABS, and vice versa. They sell glue that glues these two plastics together.

Even if you glue that ring inside the pipe, you still have to drill into the floor to secure it with at least four screws. Use Hammer drill and concrete drill bits. Bolts should be brass or stainless steel.

Quote:

---

2. What type of bit and bolts do I need, and are there good procedures for drilling through slate without cracking it?

---

There are several methods of attaching the flange. You may use Tapcons,(see image) or use a 1/4" masonry bit to drill the slate floorand use plastic inserts with wood screws t5o secure the flange. Good luck and thank you for rating my answer. Tom