Assessing damages found at a tenants move out can be the toughest part of the entire rental process. Its important to know what flaws existed before the tenant(s) moved in, otherwise there will be no proof should a tenant not agree or wish to challenge the charges taken out of their security and cleaning deposits. Hopefully you have pictures of the move in condition. I recommend to take pictures of any damages and the condition of the home after the tenant(s) moved out.
How long a tenant has lived in the home will determine the amount of normal wear & tear. Things like worn pathways in carpet in heavy traffic area should not be charged back to a tenant. However, holes, tears & stains in flooring are damage. There are other things to consider however, if the flooring is very old and you plan to replace it anyway you should let them know so they wont spend money trying to clean it professionally when they move out. Holes in walls and broken or missing fixtures is not normal wear & tear and should be paid for from the tenants security deposit funds. Tenants should leave the home in a ready to rent, clean condition when they move out.
If carpet or other such flooring was brand new at move in the condition report should state so and in that case you would use a loss of life calculation that is based on the warranty & cost to replace the damaged area. Calculation is total replacement cost divided by warranty years less the number of years of loss. So for example if the replacement cost is $1000.00, the warranty of the carpet was 10 years, and the tenants occupied the unit for 3 years. The total cost of damage to charge the tenants would be $93.00. You will need to call in a contractor to get current carpet replacement rates and quotes for the rooms with damage.
Other damages can be taken from the security deposit as well however, funds for cleaning can only be used for cleaning purposes. Funds for pet damage can only be used from the pet deposit and all other repairs etc. can be taken only from the security deposit funds stated on the lease agreement. Check your lease agreement to make sure how it is written up. Make sure you have filled out the final accounting and returned any unused portion of the security deposit within 30 days (Oregon Law). Check your states laws and guidelines regarding the correct amount of days to return security deposits and final accounting paperwork