"Mike Hartigan" wrote in message
.net...

The life expectancy of a mainstream consumer type heater
is, perhaps ten years. I have two, which means that I can expect
such a puddle an average of once every five years.

This is not likely.
1. You will get longer life out of your water heaters
if you flush them out (removing precipitate) every summer.
2. Leaks are only one form of failure. Others include
deterioration of replaceable parts (e.g. heating elements)
and irreplaceable parts.
3. If you really believed every heater will leak in its 10th
year you could simply replace them at nine-year intervals,
thus avoiding all leaks.

--
Don Phillipson
Carlsbad Springs
(Ottawa, Canada)