Majestic trees in your front yard may add beauty and shade to your property, but what’s going on beneath the surface? Are the root systems damaging your home’s foundation?
Trees can bring many benefits to your property. They add to the curb appeal, and by providing shade, they can reduce your energy costs.
It’s rare that the roots would burst through your foundation walls, but the disruption the root system causes to the surrounding soil directly impacts your walls.
Roots rob the soil of moisture. The soil around your home is an ever-changing entity, and some soils, like clay, are particularly sensitive to the amount of moisture in the ground.
Clay soil is considered an “expansive soil” and contracts and expands depending on moisture content
When there’s a lot of moisture in the ground, the soil swells. During dry periods - or if a tree’s root system is absorbing the moisture - the soil shrinks and contracts.
Soil movement can cause foundation movement. When your foundation no longer has a steady bed of soil to rest on, it can settle into the ground. This is when foundation cracks can form.
When the soil shrinks, gaps and voids form beneath your foundation. Space under the concrete reduces the structural integrity of your basement.
As dry soil contracts, it pulls away from your foundation walls, causing instability, cracks, and bowed or leaning walls.
Roots are opportunistic and grow outward to find water. If you’ve watered flowers or shrubs near your landscape, that water can attract tree roots. Mulching landscaped areas helps with water control.
Aggressive rooting species, such as willow, honeylocust, silver maples, and elm are more likely to cause damage as their roots spread than slow-growing upland species, such as oak or sugar maple.
Typically, trees by themselves (such as in your yard) have a wider root system than trees planted closely together (such as in a forest).
The Iowa State University Forestry Extension noted roots may occupy an area four to seven times the surface area occupied by the crown of the tree. So look up for an idea of how wide the root system spreads.
However, a root system may grow wider when downward growth is restricted, such as by bedrock or a high water table.
So what should you know when you want to plant trees in your yard?
Experts recommend planting trees at least 20 feet away from the home. (Make sure to call 811 before you dig.)
A common guideline used by arborists to determine a tree’s root zone is to look at a radius of one foot for every one inch of a trunk’s diameter.
Installing a root barricade in your yard can protect your foundation.