We had a very large tree overhanging our block which can be seen in the right hand side of the photograph. It wasn’t actually ours as it belonged to our neighour as it was on the other side of our boundary wall which was leaning significantly as a result. It was also blocking out a considerable amount of light to the upper flat over which it was hanging. The one on the left was ours and it was also contributing to the reduction of natural light.
Trees (and particularly their roots) need to be monitored and maintained when they are located within a distance that could affect a building because they can damage drains and undermine foundations by pressing on them. They are often found to be the cause or a significant contributing factor to ground movement i.e. subsidence. They also cause dessication by sucking moisture out of the soil (clay soils are particularly susceptible) during the dry months. This causes the soil to sink slightly and the property with it and when the soil swells again during the winter the property doesn’t necessarily go back up. If it does, it doesn’t do it evenly, which can cause significant subsidence cracking. Some trees are much higher water-demand than others.
I contacted a company called the Tree Clinic for advice who said that felling trees in one go is not necessarily the best course of action. For mature trees is may be best to remove them in stages for example 40 – 50% of the crown (with the tree being left for 6 months to a year) then a further percentage until the tree is fully removed. Other factors to consider are the potential issue of water that is not taken away from the tree resulting in it going somewhere else and what type of ground the tree is rooted in. I should get a surveyor to fully assess the damage to the wall and surrounding area who would write up a report. If we used the company then the remedy would be based on the contents of that report.
However, ahead of us making a decision our neighbour cut the tree right back and then painted stuff on the stump to penetrate the roots and kill it. Apparently it did show some growth but then it died off and nothing has happened since so it has seemed to be a good move.
We do however require the stump to be removed at some point in order to rebuild the wall.