Is a tree growing in your brickwork?

Vegetation growing in brickwork can be a common problem in historic structures when maintenance has been poorly planned through either neglect or lack of funds to manage sites. 

The Buddleia is often a usual suspect in this regard (I often find it ironic that they grow in structure or other places where we don’t want them, but I can get them to grow in my garden! Butterflies love them). If left unchecked a Buddleia can grow to a reasonable size, with an impressive root size to match it. Sycamores and other trees which find it easy to get a foot hold in structures are often problems.

Once you have cut the tree off the first question you need to ask yourself is, is the stump dead? Obviously if there are signs of new growth it’s not dead! So it’s worth keeping any new growth cut back while you try and kill the root, so as time goes by you will be able to know when it is dead. 

You may ask why not just try and remove it while it is alive? The problem which this is it is highly unlikely you will be able to remove all the root, as the tendrils of the plant will have crept into every corner of the wall. If you leave these alive in the wall, they will come back and you will have wasted your money and you will have needlessly disturbed the fabric of the structure while not really dealing with the problem.

It may be possible to remove the root if it has not had the chance to get too established but even then it may benefit from a period of time of attention in killing the root to ensure that if any root is left in the structure it is dead and ultimately inert and harmless.

As can be seen in the photo above, when you have a root which is clearly well established and has already caused damage to the wall there is only way to proceed, and that is to kill the root, wait to ensure it is dead and then wait until the timber of the stump and root start to decay and rot away. 

This is possible in a case such as the photo above where the root is not yet causing any destabilisation of the structure, while this rot progresses, care will be require to monitor this and make sure that as the bricks become loose they are removed and carefully kept in a safe place for re-use when the work to remove the dead root takes place.

Once the rot in the roots is sufficiently progressed and has lost any strength or integrity, the repair work can take place, this will still result in significant rebuilding of the masonry in and around the area of the root. 

It should not be underestimated how deep the root will have travelled, both in depth and horizontal width of the masonry. The extent of work can create it’s own problems, such in the case of the photo above, the wall is retaining the soil behind and above and therefore during planning work of this type, a ‘worst case scenario’ should always be allowed in setting funds aside to deal with these.

Ultimately the best way to avoid this unnecessary cost is to try and keep any vegetation growth in buildings and structures under control, as if left unchecked they will create a large and expensive project.