Our recent drought conditions in Ottawa in 2012 resulted in extensive foundation damage due to trees. Ottawa has a lot of homes and buildings constructed on very sensitive soils. Sensitive soils contain high water content. Tress continue to grow during the summer and a lack of moisture forces them to reach further and further underground for water. Large trees can draw water from over 100 feet away! Sensitive soils which can contain up to 40% water suddenly have their water taken away, the soil then shrinks in volume and the house settles. The worst trees for causing damage are Manitoba maple, Weeping willow, Ash, Lombardy poplar, Elms, Silver maple and similar fast growing type deciduous trees. It is rare for damage to be caused by conifers but it can happen.
trees near foundation
typical crack due to settlement
resulting separation in brick
