I’m just about ready to close the underwriting file on a sewer backup claim for a particular client. The insured owns a stratified residential property on the North Shore in a higher elevation zone. The home is a slightly older frame building constructed in the 1960’s and the insured rents out to tenants on a regular basis. Last year, during a few days of moderate rain, the sewer backed up into her main floor finished suite. The resultant damage caused over $80,000 in property damage. After the loss investigation, it was discovered that the backup was caused by a lack of home maintenance. The older home still had the original clay weeping tile system but because the drainage system was not properly maintained over the years, nearby tree roots were able to penetrate the pipes. Eventually, it clogged up and with the rain, caused difficulty for the water to drain into the city sewer resulting in back-flow into the home.
“If tree roots can penetrate past the drainage system, then it is probable to expect root penetration into the foundation.”
Most people don’t realize how serious this claim can be. On the face of it, it’s a simple water damage claim that is easily fixed by hiring a plumber to scope and clear the drainage system every few years. However, the claim reveals a greater concern – root penetration of the foundation. Weeping tiles are traditionally installed at the footing of the foundation. In newer construction, many cities have by-laws requiring a separate drainage system to be installed specifically for eavestrough drainage to prevent overflow and subsequent backup. Unfortunately, it is uneconomical for older homes to install such a system (which is why when the sewer backs up into your home, the easiest way to stop or slow the back-flow is to pull the down spouts out of the ground drain). Unfortunately, the clay pipes are heavily prone to root penetration. If tree roots can penetrate past the drainage system, then it is probable to expect root penetration into the foundation. Such penetration can cause cracks and when the water table is particularly high or when there is heavy rainfall, water will seep through the cracks and into the home. Over time, the moisture can cause hidden mould and provide internal access for insects (such as carpenter ants and termites) to enter your home. In extreme circumstances, cold weather can freeze the water in the cracks and slowly deteriorate the structural integrity of your home’s foundation.