Yes it's true that Asbestos is only harmful if it becomes airborne and you breathe it in. So it's really not a big hazard if you can cover it or seal it. But the previous discussions seem to be minimizing the dangers - I get the impression from reading them that it's a bigger hazard when you have more frequent and prolonged exposure. Well, the probability increases with exposure, but the severity is the same regardless of the number of occurences. The asbestos fibers that get in your lungs cause cancer (I think because of their small size) - One fiber can do just as much damage as 100 fibers. Do yourself a favor and read some EPA reports - don't look to this forum for guidance - none of us are experts in this field.