The impact of trees on your home

Most trees growing near buildings will typically cause no damage across the lifetime of the property, with any subsistence or structural damage caused by other factors such as soil type or foundation depth.  But as a homeowner it's always worth thinking about the impact existing trees, or trees you're planning to plant, have on your house and surrounding land.

Our first recommendation would be to have any substantial trees near your home professionally surveyed every few years to assess their overall health and to determine any pruning or felling requirements.  The subsequent report from this assessment will also help you in any future claims or when providing supporting evidence to your insurer.

What to look out for

Buildings naturally shrink and swell due to changes in temperature and humidity, which can cause minor cracks in your walls.  The time to consider action is when you find a series of small diagonal cracks appearing in the plaster around weak points such as doors and windows.  Cracks that indicate subsistence or foundation issues are normally wider than a 10p coin and look visibly wider at the top than the bottom.

At the first sign of damage or if you're worried, contact your NFU insurer about your options.  More often than not, once the problem is professionally identified the remedy is relatively straightforward.

Getting to the root of the problem

Tree roots grow at variable rates and lengths according to the type of tree and the ground it's planted in.  A good rule of thumb to consider is that tree roots can extend up to two-times the height of a fully mature tree, so if it's closer than that to your home it could be a source of future issues.

Due to their moisture absorbing properties, prolonged dry spells of weather can see tree roots dry out soil and cause it to shrink.  This can result in issues with subsistence, heaving and structural cracks in surrounding buildings or ground slabs.  Tree roots can also exploit cracks and faults in your home's footings and block drains, causing them to burst.

Wherever possible, try to keep drains and gutters clear of tree debris such as leaves and falling branches, which can all cause pipe damage.  And check any older drains with poor seals and rigid joints.  If water drains are watertight then roots will not generally cause any issues.

By and large the trees near your house will cause you no problems and any assessment of existing trees should show you potential issues you'll need to address.

Protecting yourself from the ground up

Ground subsistence has the biggest potential to cause damage to your property, especially on shrinkable clay soils - commonly found south of an imaginary line from Bristol in the west to Hull in the East.  Take particular notice if your home is up to four storeys in height and built before the 1950s as it could be most at risk from shallow foundations.

But there are ways you can prevent issues with subsistence though:

  • Avoid planting large, vigorous trees such as poplars, oaks and willows near your home or neighbouring buildings.
  • Think carefully about removing any unwanted trees.  Unless it causes immediate structural issues it could cause more extensive damage if removed.  Seek the advice of a specialist arborist and building surveyor.
  • Consider the impact a removed tree can have on the ground - it will leave space for additional moisture to collect, which can cause heaving and put pressure on building foundations.
  • If you're looking to remove an established tree, check to see if it is under a Tree Preservation Order (TPO).  Cutting a tree with a TPO can result in a fine of £30,000 or twice the value of the tree's timber.
  • Plant any new trees the same distance away from your house - or neighbour's property - as you expect them to grow when fully mature.
  • Avoid planting pyracantha and rose shrubs close to the house as they can be aggressive growers.  Wisteria can also cause issues because of its size and the moisture it soaks up from the ground.

Your building insurance should cover damage resulting from subsistence, but you can reduce the chances of your property being at risk by knowing what to look out for and following the advice above.  If you have further questions, don't hesitate to contact your NFU representative.