If he's causing damage to your property which is causing you loss (property damage, cost of remedial work, impact on you being able to sell etc... ) you could threaten to take a civil action against him.
This could be a costly way of doing things though and you would have to weigh up the chance of success, potential outcome against cost and it would be wise to talk this through with a solicitor before making any firm decisions.
Try and agree between yourselves first though, maybe, if you see a solicitor who believes you have a good case and chance of success then you could approach him on that basis, explaining the current and potential damage to your property, impact on value, potential problem in selling etc... but offer to have it sorted between yourselves within a reasonable time frame.
Maybe that will encourage him to get things sorted and, if at possible, avoid a neighbourly dispute from escalating.