We had problems in 2012 where the tree roots had blocked my drain and we had foul water running down our drive. Our neighbour initially agreed to remove the tree but changed his mind. 

It is now around 9.5 metres high and is causing even more damage. The wall has now cracked and a CCTV survey showed the tree's roots have entered my drains. Our tarmac drive is lifting due to the roots spreading under the wall, which we have confirmed with an arboricultural survey which cost us £450. 

From what I understand, re-laying the drive could cost more than £8,000 and repairing the wall could cost around £2,000. My home insurer says I could make a claim against my neighbour for this, but I have to prove the damage is caused by his tree. A structural engineer report could cost over £500.

The insurer also said they would only take the case on if it considered that the chance of success was more than 51 per cent.

I also gather that as the tree roots have entered my property, trespass could be at play. What do I need to do to make sure any claim is successful?

Jane Denton, of This is Money, replies: It is your neighbour's duty to ensure the tree does not damage your property. 

Your neighbour has known about the problems caused by the tree from as far back as 2012, yet failed to take any steps to stop the damage. 

You have already amassed significant evidence to provide to your insurer supporting your case. 

Given how far you have already taken the matter, it could be worth paying the additional £500 for the report from the structural engineer to determine how much and what type of damage the tree has caused.  

Phone your insurance provider again and get them to provide a comprehensive list of the evidence they would require from you. Your home insurer can pursue a claim against your neighbour, but only if your neighbour is legally negligent. 

The key issue is proving that the tree is responsible for the damage, and it sounds as though you have taken several sensible steps towards doing exactly that.

A CCTV survey has identified roots entering your drains, excavations have revealed roots extending beneath your wall and driveway, and you are obtaining expert reports from an arboricultural consultant and structural engineer. 

These are precisely the types of evidence insurers and courts look for when determining liability.

Your next step should be to provide your insurer with a complete bundle of evidence, including photographs, CCTV reports, expert findings, repair estimates and copies of any correspondence with your neighbour. 

Ask your insurer whether there is any additional evidence they require before deciding whether the claim has a reasonable prospect of success.

You are correct that tree roots crossing onto your land can amount to a trespass. 

In addition, where a property owner knows, or ought to know, that a tree is causing damage and fails to take reasonable steps to prevent it, they may be liable in nuisance.