It doesn't sound like there is any benefit to me serving notice beforehand. Unless I word it in such a way which compels the owner to agree with my opinion. The tree would be a future liability for the owner should it damage the property. Whether highlighting this fact would then convince the landlord the offer I made was good is anyone's guess.
I mentioned the grey area because I believe it would be difficult to pinpoint a tree being blown over to a species which is susceptible to wind damage and is already listing. Obviously cutting roots back wouldn't help in matters, but whether it could be proved that this led to the demise of the tree should we experience gale force winds...
Is there any way of “serving notice” of root tresspass before roots cause any damage? As in – your trees roots are on my land, if they cause any future damage (to property, drains, landscaping) I would like you to rectify?
sure - but he is not obliged to rectify just because you've "served notice".
you should, if you're that way inclined, put him "on notice" that if you have evidence his roots have caused damage to your property that you will sue him.
I believe I am within my rights to cut these roots back to the boundary?
I understand if the action of cutting the roots back were to ultimately cause the trees death I may be liable...
...however it looks to be a grey area should the tree blow over after losing support of roots on my boundary?
not really heard of this being a "grey area" - if the tree falls over because you've destabilised it you will be found liable.
If not beforehand then after these roots are cut back could I then “serve notice” saying that any future incursion or damage will be their responsibility to remove?
again, sure you could send such a letter but it is meaningless - they are NEVER responsible for removing the roots.
of course, that doesn't mean they mustn't feel responsible and could ask cut the roots back to avoid causing damage.
Kind regards, Mac