If you are building your treehouse on stilts, you will need to dig holes near the tree for the foundations of the supports. The concrete foundations should be about 50 cm deep (1.6 ft) and have a diameter of 30 cm (1 ft). You will inevitably come across roots! What to do?
The role of roots is often underestimated because they are invisible in the soil. Yet they are just as important for the tree, and their volume is about as large as the tree crown. Any damage to a root means loss of nutrients and a damaged area where rot can spread.
- Individual smaller roots ø < 4 cm can be cut (on a mature tree). Roots ø < 2 cm are usually no problem. Always compare the roots with the tree crown, then you will get a sense of what you are doing to the tree.
- Make sure that the soil is not compacted too much during and after the construction work; the roots need a loose, airy soil to remain functional. So do not drive around with cars, excavators or lifting platforms near the construction site.
- Avoid stress in the immediate close to the trunk: footpaths, crowds or car parks. A good measure against soil compaction is bark mulch or raised paths on poles.