Tree-lined streets and beautiful landscaping add charm to any home—but beneath the surface, those large, sprawling roots may be doing more harm than good. Tree roots foundation damage is a real concern for homeowners, especially in areas with older homes, clay-heavy soils, or mature trees planted too close to the house.

In this blog, we’ll break down how tree roots can cause foundation problems, the warning signs to watch for, and the steps you can take to prevent serious structural damage.

How Tree Roots Damage Foundations

Contrary to popular belief, tree roots don’t usually break through concrete. Instead, they exploit existing weaknesses in your foundation or create problems indirectly. Here are the primary ways roots cause foundation issues:

1. Soil Movement

Tree roots absorb large amounts of water from the soil. Over time, this causes the soil—especially clay-rich soil common in Montreal—to shrink, dry out, and become unstable. As the soil shifts or contracts, your foundation can settle unevenly, leading to cracks or even structural instability.

2. Hydrostatic Pressure

Some tree roots grow aggressively toward moisture. If they find water accumulation near your foundation, they may expand in that direction, increasing hydrostatic pressure against basement walls. This pressure can cause walls to bow, crack, or leak over time.

3. Invasion of Drainage Systems

Tree roots are naturally drawn to moisture and may invade weeping tiles, French drains, or sewer pipes near your foundation. This can block proper drainage, increase moisture near the foundation, and lead to long-term damage.

Signs of Tree Root-Related Foundation Damage

Watch for these early warning signs:

  • Cracks in basement walls or foundation slabs

  • Uneven floors or doors that won’t close properly

  • Water pooling near the foundation

  • Roots visible near the surface, growing toward the house

  • Foundation settling or shifting on one side of the house

How to Prevent Tree Roots from Damaging Your Foundation

1. Choose the Right Trees

When landscaping, avoid planting fast-growing trees with aggressive root systems near your home. Common problem trees include willow, poplar, silver maple, and elm.

2. Maintain a Safe Planting Distance

A good rule of thumb: plant trees at least as far from the foundation as their expected mature height. For example, if a tree will grow to 40 feet tall, keep it at least 40 feet from your home.

3. Install Root Barriers

Root barriers are physical or chemical barriers placed between your home and nearby trees. These systems redirect roots away from your foundation while allowing the tree to continue growing.

4. Monitor and Maintain Drainage

Ensure that water drains away from your home. Keep gutters clear, install downspout extensions, and maintain proper grading around your foundation.

5. Get Regular Foundation Inspections

If you suspect foundation movement or have large trees near your home, consult a foundation repair expert. Early detection can save thousands in repairs.

Need Help Protecting Your Foundation?

At Marco – Foundation Repair, we specialize in identifying and addressing the root causes (pun intended) of foundation damage. Whether it’s cracked walls, drainage issues, or shifting soil due to tree roots, our experienced team can help restore your home’s stability.