Landlord claims damage; tenant claims wear and tear..

[Jayde Brown]

My question is in regards to wear and tear; specifically, plumbing below the floorboards and inside the walls on a 20-year-old rental cottage. If there is leak not readily noticeable, as in occurring inside the bathroom wall and down into the subfloor, is this considered wear and tear? Leak wasn’t a gusher, just a few little drops every 8-9 mins… 

Also is the toilet wax ring/bolts/supply line replacement- which was not due to misuse or abuse or damages, just age-the responsibility of the moved-out tenant to pay (taken out of security deposit)?  

Just want to hear your thoughts about wear and tear. TIA.