Question
spruce tree
I have a 30' sitka spruce (my best Internet aided I.D. guess) 10' from my house. Large roots have started appearing on the surface on the house side of the tree in the past 2 years. Each year the roots protrude more and more from the ground. My concern is the roots damaging the foundation which extends about 4' underground. The house is 15 yrs old and the tree would have been planted sometime around then.
AnswerThe roots will not be a problem since they are mainly on the first two feet of soil. The foundation footing is normally much deeper than this and the roots will either turn along the foundation or go deeper and not bother the foundation. BUT the tree is too close to the house and the branches will begin to rub the house. Probably not sitka spruce since it grows usually manly the coast of Washington and Alaska. Spruce trees have a spreads of about 20-30 feet meaning the branches will grow out about 10-15 feet from the trunk. This tree can be pruned to try and keep it size within reason but planted right next to the house this will take a yearly running.
Roots are often blamed for damage to foundations. In reality, roots are rarely the cause of the problem. Though small roots may penetrate existing cracks in foundations, they are incapable of causing mechanical damage through their growth. Soil subsidence can result in damage to structures. Under very special circumstances roots can contribute to this problem. When soils are prone to shrinking substantially during periods of drought, and if foundations are shallow, roots can contribute to depletion of soil moisture under the foundation, causing it to subside.
Major tree roots often grow within a few inches of the soil surface. These surface roots could become a foot hazard or cause difficulty in mowing, and are easily injured. Removing these roots may disrupt the moisture supply to the tree, causing serious stress. Covering them with soil could cut off the oxygen supply to the fine roots in the soil below. Both situations could lead to decline. The best solution is usually to mulch the area under the tree with compost and/or wood chips. These materials are porous enough to allow sufficient oxygen supply to the soil and may actually encourage fine root growth.
I would either prune the tree and see what you think of that look or remove it. If you like the tree prune it. Give it a good hair cut but leave green foliage on the branches and do not cut the top off. Spruces, firs and douglas-firs don抰 grow continuously, but can be pruned any time because they have lateral (side) buds that will sprout if the terminal (tip) buds are removed. It抯 probably best to prune them in late winter, before growth begins. Some spring pruning, however, is not harmful.
