In this case you may have to serve your tenant with a notice based on damages which is Form N5. You will have to find out the cost of repairing the damage before giving this notice. Once you serve the notice the tenant will have seven days to correct the problem otherwise you can apply to the Landlord and Tenant Board for an order to evict and compensation for the damages. You can obtain this form on the Landlord and Tenant Board’s website at https://tribunalsontario.ca/ltb/forms/