Lawsuit over B.C. condo owner's overflowed toilet highlights danger of flushing floss

VANCOUVER -- A legal dispute between neighbours at a B.C. condo building that began with an overflowed toilet highlights one of several reasons people should never flush dental floss.

The case was decided this week in the province's small claims court, which ordered condo owner Robin McLean to pay $1,270 for water damage caused to his downstairs neighbour Xiangfei Kong's home.

McLean's toilet overflowed on July 20, 2020, spilling water that ultimately left Kong with a hefty bill for ceiling repairs.

A plumber later found a blockage eight feet deep in McLean's drain made up of floss and toilet paper, according to an invoice presented to the Civil Resolution Tribunal.

The condo owner argued the blockage must have started before he purchased the unit about 18 months prior, and that he had no way of knowing it was there.

Part of his argument was that his son, who "only has six teeth and has never used dental floss," was living in the unit at the time, according to the tribunal's decision.

Tribunal member Leah Volkers was not convinced.

Volker noted that McLean's son wasn't a party in the dispute and that the father didn't provide any details about the living arrangements, including whether he lived in the condo as as well.

"On balance, and considering the available evidence, I find the most likely scenario is that the blockage occurred as a result of dental floss being flushed down the toilet by either Mr. McLean or his son," she wrote.

While no one submitted expert evidence on the danger of flushing floss, the tribunal determined that was "ordinary knowledge," and that doing so "falls below the standard of care of a reasonable toilet user."

Beyond causing run-of-the-mill toilet clogs, officials warn that floss can consolidate with other materials and contribute to serious issues with municipal sewer systems.

It's one of several items listed as "unflushable" on the website for Metro Vancouver, which spends more than $100,000 a year de-clogging regional pump stations.

Most floss is also made of nylon coated in wax, and is said to take decades to decompose while presenting a possible hazard to fish and other animals because of its tear-proof design.

Volkers found McLean liable for negligence, and ordered him to pay the cost of Kong's ceiling repair along with $4.83 in pre-judgment interest on the bill.