Q:
Is it possible to plant trees on top of an Allan Block retaining wall without compromising its integrity?
A:
This will vary by the species of tree being planted, the anticipated height of the mature tree, and the starting size of the tree’s root ball. Without knowing more about your site or the retaining wall, we can only give general guidance. If these walls have been previously designed by a professional engineer, please consult with them prior to any detailing or construction.
There are numerous situations where it is acceptable to cut the grid behind the wall to facilitate obstructions such as fence posts, culverts, and in your case planting trees. A general recommendation would be to ensure the tree will be at least 3 ft (1 m) behind the back of the wall.
When digging the hole for the tree, care will need to be given once you reach the layers of geogrid so that you cut through them. It is important not to tear or pull the geogrid; often times this will mean hand digging. For addition geogrid information, we would recommend contacting the geogrid manufacturer to discuss your particular situation and the performance of their grid.
If you have any further questions, please Contact Us on allanblock.com or post more on our blog!
