Many homeowners worry -- rightly so -- about the dangers of fire and what it could do to their home and prized possessions. But water damage can be just as devastating and now there are concerns that thousands of homes in Ontario and possibly other parts of Canada could be outfitted with defective toilet water supply lines.

The water supply line attaches to the underside of a toilet and insurance companies says they have been dealing with an increasing number of floods due to the plastic nut on these lines failing.

Dan Bernardo of Winmar Restoration Services says "sometimes the hose will be completely snapped off with water spraying everywhere. Sometimes it will just be cracked with water spraying out the side."

Often these hoses break on toilets on the top floors of homes which can lead to three floors of flood damage.

That's what happened to Linda Bradley of Markham, north of Toronto. She recently had her home flooded when the plastic nut on her upstairs toilet broke while she was at work. She came home to water pouring out the sides of her home.

"It was devastating. I knew I didn't leave anything on, yet when I came in water was pouring from the ceiling. It was like I was walking through a production of singing in the rain," she said. 

The toilet supply lines causing problems may have been manufactured offshore and are not CSA approved.

Giffin Koerth of Toronto, is a forensics firm investigating the rise in these cases for the insurance industry. They provided this helpful information to CTV News.

"The failures typically occur between one and five years after installation. The plastic of these nuts tends to be a low grade polyacetal material and often show significant porosity and evidence of generally poor injection moulding practices.

In some cases the plastic nuts may also have been over tightened. The best way to determine if you have one of the questionable hoses is to check the hose for the CSA stamp. The stamps are very small and often you will need a magnifying glass to see them. There should also be a manufacturer's mark on the hoses.

Unfortunately, even the CSA stamp can be fraudulent so this is no guarantee you do not have one of the questionable hoses. When replacing flexible toilet connector hoses, purchase a hose produced by a major North American brand which bears the CSA label. Your local building supply store or plumbing outlet should be able to help you find the right hose. Then have a licensed plumber install the hose.

It is important that the installation steps listed by the manufacturer be followed to prevent over tightening of the plastic nut. For an added margin of safety buy a hose which incorporates a high flow rate stop valve. These valves are intended to close if the hose or nut fails and the flow through the hose is very rapid."

If you have concerns that you may have these defective hoses in your home, check for the CSA symbol or have them replaced. CSA approved hoses cost as little as $5 at your local home improvement store. You can replace them yourself or have a plumber do it for you.

As for Bradley -- she can't believe such an inexpensive plastic nut caused her so much trouble.

"It really is a shame especially when you think your home is built to code and than you have a devastating flood. I will be out of my home for six to eight weeks. Everyone should be aware of this potential problem."

Key Points:

  • Home insurers are using forensic engineers to investigate the large damage claims resulting from cracked plastic nuts
  • There are a number of lawsuits before the courts as a result of these faulty nuts. Insurers are suing homebuilders, plumbers, suppliers or distributors of certain hoses
  • Some home owners have also reported significant damage after the hoses themselves simply split open
  • Buying a new hose certified by the Canadian Standards Association (CSA) is one way to try to avoid potential damage
  • When going away on holidays shut off the main water source to your home to avoid any chance of flooding while you're away