Could spray foam insulation around a drain pipe have caused a toilet to loosen?

Question

About 3 weeks ago, we had a problem with our toilet. The toilet is on the first floor. It was leaking. We called in a plumber who said that the wax seal was bad and he fixed it. After doing this, we had an insulation person come in and remove our old insulation in the ceiling of our basement. For the most part, he did not put any insulation back. However, in certain places he put foam insulation in including around the waste pipe of the toilet.

Yesterday, I discovered that the toilet was moving when I was sitting on it. I called the plumber and he came out today to fix the problem. He believes the problem with the toilet was caused when the foam insulation was put in. He explained that when the foam insulation is sprayed on, it expands. This expansion caused the problem. They also put up a generous amount of foam insulation around the waste pipe of the toilet. He fixed the toilet without charge.

Do you think the problem was caused by putting up the foam insulation?

Answer 1

The plumber probably did a poor job the first time. Hopefully he corrected it the second time.

There is not much holding down a typical toilet. The wax seal, and a couple of tiny bolts that are NOTHING compared to a 200 pound person heaving themselves down onto the toilet. For stability a toilet needs two things: 1) A solid, even floor on which to rest, 2) an adhesive or silicone seal around its bottom edge to prevent it from moving. My guess you had neither, which is why the wax ring failed in the first place, and the plumber probably did not fix the problem (uneven floor and no adhesive) the first time. What did he do differently the second time?

It's hard to imagine how expanding foam sprayed in the basement ceiling would cause the toilet to move. If it was sprayed between the waste pipe and ceiling, it would pull down on the waste pipe, which would be resisted by the toilet flange and pipe hangers. If the toilet flange was loose, and easily pulled down into or through the floor ..... that too would be the plumber's fault. If it was properly mounted to the floor, you would need some freakishly powerful expanding foam, that would have to blow apart your floor boards etc. You would know if that happened. If the foam was sprayed BENEATH the waste pipe it would just expand into the basement space.

Maybe foam found its way up through cracks in and around a well-mounted toilet flange, and pushed up on the toilet that way? Still ... if it's all properly done that should not move the toilet, and if it did .... it would be obvious. You'd see the plumes of foam sticking up through the floor and holding up the toilet. That's possible .... but I'd go with the more obvious explanation. You had a difficult job: A wax ring failed because of an uneven floor and maybe a poorly installed flange. The plumber didn't fix any of the underlying problems the first time. Why look further than that?