How to protect against my neighbour's trees

Question

My neighbor has planted a row of pine trees along our boundary. The trees (perhaps 10 of them) will grow to 14m tall, yet are barely 4m from my house (and 2.5m from his). The ground is heavy with clay so I'm guessing the roots will spread a distance. Between the fence and my house is a concrete driveway. He has planted the trees so close to the fence that they already push against it and they are currently only 6m tall.

To make the situation worse, my neighbor has since sold the house so the new owner may simply say it is not their problems since they bought the house that way. I have not met them yet.

So my questions:

How bad is this for me? Will the roots affect my driveway or, worse, my house?

Is there any way to protect my house against these trees?

Answer 1

The Structural Engineers Pocket Book summarises some recommendations from the UK's National House Building Council (NHBC).

I will assume the tree has a moderate water demand and a high plasticity for the soil. In the current condition the D/H ratio for the trees is 4/6 = 0.67 and in the final condition when the trees are 14m high the ratio is 4/14 = 0.28.

Checking against the chart for high plasticity soil the depth of influence for the current condition is 1m (this is the minimum for this type of soil in the UK) and for the final condition is 1.3m. In principle, provided your building foundations are deeper than these then shrinkage caused by drying out of the clay due to the tree's roots should not be an issue. This is of course based on local practice and so it would be worth getting checked out by a local professional if in doubt. This shrinkage is typically the biggest issue for structures in the UK rather than root damage, although given time roots can cause problems. Conifers tend to have deeper rather than wider root systems though.

Regarding protecting your house, it will somewhat depend on the layout of the house, the structure and the design of the foundations so you will probably need to seek professional advice. One point to note with regard to cutting the trees down, this has been known to cause as many problems as not cutting trees down because as soon as you cut them down you reduce the amount of water being drawn from the clay causing swelling. Because these trees are relatively new, this shouldn't be an issue but maybe something to beware of.

Answer 2

First, start with the easy solution. Welcome the new neighbor and mention how the trees will eventually threaten their own property (at that distance, the branches will be growing into their siding before impacting your home). You may try to convince them that an evergreen shrub/hedge will give them better privacy with a lot easier maintenance and less damage.

If they don't find the trees a new home (or chop them down if you insist), then check the local laws to see who is liable if the tree falls on your home and whether you're allow to cut the branches that encroach on your property.

For the roots, you can always cut them if they are close enough to the surface. If you have a bed along the side of the driveway/house, taking a stab with a shovel along the edge of the bed where it borders the lawn would be a good way to notice any roots, hopefully before they cause any damage. I'd say, keep an eye on the neighbors home. The tree will damage their place first, so you get an idea of what to prevent in advance.

Answer 3

If it's going to be a problem with the roots for your house... the new owner next door will have the same problem, but twice as soon. Chat with the neighbor, see what they think of the trees, and make sure it's okay to trim the ones once they cross the fence, so you can keep your driveway clear.