We’ve discussed the many plumbing quirks and pitfalls of older homes in Toronto on this blog before. We’ve discussed how, even though these houses come with a great deal of character and history, they might not always manage your modern plumbing needs properly. Plumbing in Toronto has changed and your house needs to change with it.

One such feature that we’d like to discuss, which you will find in many old Toronto houses, is a building trap. It sounds much more ominous than it actually is, but it can still wreak some pretty bad havoc on your own, albeit indirectly. But before we jump into talking about why a building trap is problematic, it’s perhaps best to give some context.

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What Is a Building Trap?

To give some context, let’s start by talking about the main drain line in your older Toronto home.

Many older houses in Toronto have a main drain and sewer made of clay. This might not seem like such an issue, until you consider that clay is pretty susceptible to the elements (drop a clay pot and it’s liable to break – not a quality you’d exactly encourage in a building material). Add to that the fact that those pipes are original, which means they are most likely very old. Not a great foundation for your plumbing, right?

Because vitrified clay pipe is heavy, they used to make them in short pieces, so that the plumber could lift them and easily work with them. The problem here is that numerous pieces mean numerous joints, and every joint is a potential weak spot. Joints can easily be shifted, collapsed or have roots penetrate their small cracks.  

At that time, plumbers used to install what’s called a “building trap”, which was a 4” U-shape pipe on the main drain line. The purpose of this trap was to prevent dangerous sewer gases entering the house. The bottom of the U-shape would inevitably trap a bit of liquid, disallowing any noxious gases from making their way from the city sewer into your precious home. It was all very well intentioned, but unfortunately, as we’ll see, caused some issues in the future.

What Harm Are These Building Traps?

These clay traps are, unfortunately, the number one problem with underground drains. Just like the little u-shaped pipe under your kitchen sink, for example, this trap might become clogged over time and with prolonged usage. But unlike the u-shaped pipe under your kitchen sink, this trap is buried underground, making is difficult to get to and to clear. Even if you did reach it with a drain cleaning tool like a snake or hydro-jet, there would be no guarantees the machines could navigate the brittle clay or sharp turns.

As it becomes clogged with stuff, sewage will start backing up into your basement, introducing noxious gases and destructive waste. What was originally intended to help keep your home safe from this terrible sewage backup could very well be the thing that eventually causes it. That’s the plumbing version of poetic irony, for sure!

Another problem with these building traps is, as mentioned above, they are susceptible to root infestation and soil movement. As a tree’s roots crack and infiltrate a pipe, those roots clog the trap and catch even more passing debris. Again, this can cause awful sewage backup.

No only are these fixtures problematic, but they’re also unnecessary these days. Plumbing codes changed and currently plumbers install P-traps for pretty much every plumbing fixture inside the house. This makes that sole outside trap useless. The Code also states that double trapping is prohibited, since air can get caught between the two traps.

Removing Your Building Trap

Before the worst happens, get rid of that old building trap. If you are thinking about acquiring an old home in Toronto, or have recently bought an old home – or even if you’ve just gotten lucky so far with your old building trap – don’t hesitate to have the trap removed. It will only cause you headaches in the future, and the quicker you replace it, the better.

Mister Plumber, in addition to offering the best drain inspection services in the city, also offers building trap removal. With the removal, we also include the installation of a backwater valve and clean-outs for pipe maintenance. A downstream sewer clean-out is mandatory, because a snaking machine cannot go through the body of backwater valve. It is also very convenient for city workers who can check their side of sewer pipe.

You might be reticent to remove your building trap for fear of the cost, but you don’t have to fret too much. In addition to helping with replacing lead pipes in Toronto homes : trap removal, partial clay pipe replacement with PVC, and basement flood protection with a backwater valve, all receive a handsome rebate from the City of Toronto.

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The City understands the burden that these old plumbing techniques have caused homes and homeowners, are their rebate program is meant to ease all homeowners into the 21st Century – and into a better plumbing system. For the rebate process, Mister Plumber takes care of permits and provides all necessary information needed to apply for the rebate.

The building trap that was once installed to keep sewage backup out of your basement might be the very thing causing sewage backup now. And whereas in the olden days the basement usually wasn’t used for anything too important, nowadays we use it for all sorts of important tasks and purposes, including storage. Don’t let your basement be ruined by sewage backup, all because of an out-dated clay building trap.

Your home may be old, which is lovely, but it doesn’t mean your plumbing should be! Call Mister Plumber today, and our expert plumbers will help take out the old and usher in the new. Using up-to-date methods and materials, we’ll make sure your investment, and your family, stays as safe as possible.