What is the problem with trees and buildings?
Things to bear in mind if you're concerned about trees near houses and other buildings;
- It must be noted that many trees grow near buildings and, in most cases, these will not cause any damage
- However, sometimes trees growing near buildings can cause major problems, especially after a long period of dry weather
- Subsidence is the main problem posed by trees, but there are also the physical threats caused by falling limbs or structural failure of the main trunk
Structural damage caused by subsidence
- This is generally only a problem on shrinkable clay soils. Buildings up to two storeys constructed before the 1950s are most at risk, as they frequently have foundations only 50cm deep
- Roots may block drains, which burst as a result. This can lead to the formation of cavities where water flows into the soil. Older drains with poor seals and rigid joints are most susceptible
- Branches can cause damage to roofs and guttering. Suckers can disturb paving, and stems can rub against walls. Buildings of more lightweight constructions, such as garages and sheds, are most at risk
Just how can tree roots cause problems?
- During prolonged periods of drought, trees can further dry out the soil to the extent that clay soil will shrink. This can result in subsidence and structural cracking, particularly around windows and doors
- Tree roots are unlikely to directly penetrate sound footings, but can exploit any cracks or faults (perhaps caused by soil shrinkage or heave), thereby compounding the problem as they extend and expand
- Tree roots are sensitive to water, and this is what causes them to grow into drains. If the drains are watertight, then tree roots will not generally trouble them
Protect Your Foundation With a Tree Root Barrier
Tree roots will search as far as they can for water, and the only way you can certainly protect your foundation with trees nearby is to install a tree root barrier. These usually consist of an impermeable, strong and flexible material such as rubber, plastic, fiberglass or PVC siding. The most effective root barriers are thin plastic fabric sheets that have dots of herbicide on them. They will prevent the roots from growing any farther without killing the rest of the tree. With some knowledge of how to install a root barrier around your house, you can protect your foundation