Tree Roots Vs. Patio Pavers
Beneath a magnificent oak, an uneven patio
I recently purchased an older house that has a gigantic oak tree in the middle of the back patio. The tree's roots have pushed up the patio's large stone pavers, making them very uneven and creating a tripping hazard. Also, many of the pavers tilt toward the house, directing water toward the basement. Can you suggest a solution that doesn't call for cutting down this magnificent tree?
— Hildburg, Bernardsville, NJ
Roger Cook replies: Cutting the roots might seem to be the most obvious solution, but that can lead to rot in the tree. Besides, cutting the roots may weaken the tree to the point where it could topple over. So let the roots do what they will and look instead at changing the patio.
Here are four tree-saving solutions to consider:
Remove the pavers, cover the roots with a new layer of setting material such as sand or stone dust, and then reset the pavers, now somewhat higher, with a slight slope away from the house. This will leave a raised edge that you'll have to rein in with some kind of edging.
Get rid of the pavers entirely and create a pea-stone patio, which can adapt to whatever the roots do. The downside is that pea stone is not as neat as a paved patio, and requires some maintenance: You'd have to rake it and add stone periodically to maintain a level, trip-free surface.
Replace the pavers with an on-grade deck. The only intrusion into the root zone would be the footings, which should be carefully placed to avoid the larger roots.
If none of these options are to your liking, how about moving the patio to a sunny area farther away from the house? Then you can create a garden under the tree by adding 2 to 3 inches of soil and planting perennials or ground covers between the roots. And if you want a pathway through the garden, place the stepping stones between the roots too.