Charge tenant to replace carpet/what qualifies as "normal wear"?

[Sarah Buchanan]

How does one determine what qualifies as "normal wear and tear" with regard to carpet?  I had a tenant just move out after a 12 month lease and, while the carpets (in bedrooms) were not brand new and had a couple of small stains (I took detailed photographs), they are now horribly stained and completely unusable.  To me, this is definitely not normal wear for a 1 year lease.  They've done other damage as well so they will already be losing some of their deposit but the carpets will take a big chunk.  I don't want to end up in trouble for charging for "normal wear and tear" - any great resources for determining this?

[Gary L Wallman]

Permanent stains are never normal wear and tear.

For most items the difference can be determined by asking the question; did this item wear out gradually due to use or was it damaged by accident, carelessness or abuse?

Carpeting should last 8 to 10 years.