A building trap, also referred to as a sewer trap is part of a plumbing system which has been rendered obsolete dating as far back as the 1950’s. If your home was built before the 1950’s then it probably has had or still has a building trap. A building trap is located underground on your main sewer line usually just after it exits the foundation of your home towards city sewers. Building traps are made of clay which has long been discarded as a drainage material due to its vulnerability to failure. When building traps were installed in old Toronto homes, its function was to protect your home from sewer gas by constantly holding a portion of water in a the bottom of a U shaped bend of the pipe. By holding water in theory it would prevent gases from entering your home.
Today, every fixture in your home has its own trap. Your kitchen sink, your bath tub and your toilet all have their own individual traps designed to keep away sewer gas rendering a building trap redundant and useless.
Building traps serve no purpose in modern homes not only because today sewer gas protection is available at every fixture, but because it is very often the cause of most basement backups.
An old building trap is the weakest point of old drainage systems and usually the cause of basement sewage backups. If you want to prevent a basement backup then your first step is to remove your building trap.
There are many reasons that building traps fail the most common is a result of the U-shaped design. The U-shaped design of the trap collects sediment and debris eventually choking the drain and causing a backup. Mechanically clearing a trap using a snake or hydro-jet is not always possible due to the nature of the U bend of the trap as even modern equipment will not be able to negotiate the sharp bends.
The clay material which building traps are made of also contribute to their failure. Today clay drains are not an acceptable material for new drain installation for many reason. Cement joints used to connect clay pipes shift over years causing blockages, breakages and root penetration to occur.
Modern homes have underground drain systems made of seamless plastic pipe with a proper gradual slope that carries waste efficiently to city sewers.
Your building trap is located underground on your main sewer line usually just outside the foundation of your home. Despite the fact that it is buried beneath the soil there are some clues that may suggest that a building trap is present. Looking onto your front yard if you have a building trap there is usually a breather cap or mushroom cap will be present in the front of your house. This is not always a clear indicator as over the years the breather may have been removed, buried or paved over but the trap still remains.
A video inspection will confirm exactly what is happening with your underground drains and it is the best way to locate and confirm if you have a building trap. It is also the first step in the removal of a building trap.
Once the building trap has been identified and located using the camera and locating tool, Advanced Plumbing will carefully excavate and expose the trap. The next step is to remove the problematic trap and replace old clay pipe with modern plastic piping which is impervious to root penetration and is the standard in modern drains.