Re: mortar flange ?
Posted by Charlie Mcguire on February 23, 2003 at 14:16:03:
In response to Re: mortar flange ?
: I'm doing some basement rework in 35 yr old house. I took up the basement toilet to find what appears to be
: mortar globbed around the top of the waste pipe instead
: of a flange. Toilet was anchored into the mortar with big wood screws. Of course where the screws were anchored is pretty gungy and loose. The rest of the mortar is hard. The mortar is also dripped/dried on the inside of the waste pipe. It seems pretty ad-hoc.

: I want to put a tile floor down in this area.

: How can I fix this up right (more detail is better for
: me who is not a plumbing guru :))

: Thanks.

Update: After more investigation, here is what I found. The drain is cast iron. From the basement floor to a depth of about 6 inches appears to be black plastic (ABS?). Both are the same diameter pipe (about 3-7/8). There is about 1/8 gap where the two materials meet. There is heavy aggreg mortar surrounding the ABS (1" either side). Concrete lead lag inserts were embedded in the mortar but deteriorated. The toilet with wax ring was simply set on top of the mortar and anchored with lag screws.

There had been moisture underneath and the screws rusted and the mortar aggregate surface is deteriorated in places.

I chipped out the loose mortar. At the hardware store I found a PVC closet flange with stainless steel outer ring. With cleaning the ABS surface and a little coaxing, this should fit tightly into
the inside dia of the ABS pipe. Should this be glued, caulked in place?

Can you experts tell me if this is the right way to go? If so, what would be the best way to repair the mortar surface and anchor the flange? My initial thought was to drill holes and use lead anchors with lag bolts again - though I would put generous amounts of silicone caulk on the underside of the flange to inhibit any moisture penetration. Can this heavy aggregate mortar be drilled ?

Thanks again.

Replies to this post
There are none.