A fellow landlord named Don has some helpful advice regarding water damage. 

Don writes:

"I recently experienced two separate instances of water damage to my properties.  A hot water heater leak at one (new carpet in three rooms) and a clogged discharge line in a second floor A/C unit (ceiling damage).  

The tenants were asleep in both cases. I found in searching the web some very inexpensive water alarms that require no installation that alert tenants to water leaks so they don't sleep while the damage is being done. 

There were several choices of alarms, I selected the ones at  www.buddybrand.com , they were the least expensive. "

Thanks Don for your helpful tip,