When you think of a sewer clog, you might envision excessive amounts of waste blocking the pipe. Nonflushable wipes, nappies and serviettes can certainly prevent water from reaching its final destination.

However, one of the biggest contributors to sewer clogs has nothing to do with what you pour down your drain or flush down your toilet. Rather, your primary source for backed-up pipes may be shading your window right now: your trees.

Tree roots thrive in moist, nutrient-rich environments, and naturally, your plumbing seems like the perfect place for those small shoots to explore. But if left unchecked, those roots can worm their way into the hairline cracks of your pipes and grow large enough to block your drain. In some cases, tree roots can wrap around your pipelines and cause them to collapse completely.

If you want to avoid expensive plumbing repairs in the future, use the following techniques to keep roots under control.

1. Plant Trees and Shrubs in Appropriate Locations

Although root systems vary from tree to tree, the average root system extends out at about 1.5 times the height of the tree. Consequently, you'll need to account for the tree's root system and the location of your sewer line as you plan your landscape.

Ideally, you'll want to plant larger trees far away from any pipes. But if you need to plant a few trees and shrubs nearby, look for slow-growing species that have a small root ball. Some appropriate trees could include Amur maple, Japanese maple, flowering dogwood, ginkgo, crab apple and sourwood.

2. Install a Physical Root Barrier

As you plant, you can insert physical barriers that redirect roots away from your plumbing. Depending on your budget and your needs, you can select from a variety of materials and styles.

• Solid barriers.  These corrosion-resistant barriers rely on fibreglass or plastic to create an impermeable wall. But keep in mind that they may keep the water from draining properly, and roots can still grow around the barriers if you choose the wrong size.
• Permeable barriers. These mesh screens allow water and small roots to pass through, but they prevent larger roots from pushing into your plumbing. Permeable barriers, like solid barriers, won't work effectively if you choose a small size.

If you're not sure what type of root barrier to pick, talk to a professional landscaper and arborist for advice.

3. Insert a Slip Line or Replace Your Pipes Entirely

Unless you tear out your trees entirely, you can't always pick and choose where your trees grow when you move into an older home. Furthermore, planting a root barrier doesn't work as well when the root system is already established and wrapped around your plumbing. However, you can keep roots from doing further damage with a few minor adjustments to your plumbing.

If you have older pipes, hire a professional to lay new lines. The newer materials will be less likely to leak and crack, so roots can't penetrate your plumbing. And if you have fairly new pipes that have already suffered damage, hire a plumber to insert a new slip line. This seamless liner feeds into your existing pipes to create another barrier that roots can't breach.

4. Try Foaming Root Killer

For trees that have an extensive root system, you can remove some of the growth inside your pipes without damaging the rest of the tree.

When you hire a plumber to clear your pipes, he or she can flush the system with root foam. The combination of metam sodium and dichlobenil sticks to the walls of the pipe. As roots contact the chemical, they'll dry out and die within a few hours. The remaining residue will deter new roots from growing in the same location.

Enjoy Clear, Efficient Pipes and Plumbing

These four tips should help you keep your tree roots under control. If you follow them carefully, you can prevent unnecessary damage to your plumbing and save hundreds of dollars on repairs and replacements.