Have you recently spent a huge amount on the sidewalks and now cracks are emerging onto the surface? Ever wondered why did that happened and how can you fix the concrete cracks or avoid it in the future without harming the trees planted around?
Damage to Sidewalk & Trees –
The roots of trees that grows under sidewalks often cracks or lifts the pavements thereby causing a situation of tripping hazard.The supporting roots of a tree that started growing under or next to the sidewalk always follow the cracks on it to find air and water and in turn its creates and enlarges the cracks leading to the damage of the sidewalk concrete. Likewise, to repair or avoid the sidewalk when you cut the supporting roots, it may cause the tree to die and tree loses its mechanical support.
Various ways to avoid damage to the Sidewalk and the trees around.
1.When you are planting new trees, plant them at-least 3 feet away from the pavement. Trees which might grow up to 30 feet in size should be planted 3-4 feet away from the paved areas and for trees growing 50 feet or more there should be a minimum distance of 8 feet between the sidewalk and the tree.
2.You can also trim the roots but its a very complex method you need to be very careful of not damaging the tree. Never try to cut the larger roots as they are the major mechanical support as well as the carrier of nutrients and water. Always cut the root as clean as possible and as far away from the trunk.
3.You can always opt for modifications which can be done under the pavement or just next to it to reduce root growth by installing root barriers alongside the sidewalk or beneath the pavement concrete you can install a root excluding base. Root barriers such as a simple wall made of plastic or other impermeable material planted at-least 18 inches deep to divert the growing direction downwards or else copper or nylon screen to allow passing of only water and nutrients but not the roots. Many people also use root inhibiting herbicides.
4.By building pavement bridges or simply raising the sidewalks over the roots to allow root growth beneath. These pavement bridges are supported by concrete piers near the tree.
5. In case of minor damages and movements you can always bridge the small gaps and create a smooth transition from main sidewalk to broken edges by using asphalt wedge to minimize the tripping hazards. You can also grind down the raised edge if the displacement is less than one inch.
In other cases you can also think of redesigning a portion of the pavement to curve around the obstacle but always remember to leave enough room for the roots to breath.