Direct Devil;
Asbestos health claims are one of the large and difficult issues for insurers.
1. Can take years to show, but if claimant can show that he removed your roof in 2014 and contacted asbestosis illness in say 2034, he then has a claim.
2. Asbestos claims are always of high value, which is not much good to insurer or the poor ill person.
3. Am told that to buy Google ad word for Asbestosis is very dear because there are so many ongoing Asbestos claims.
4. In short Asbestos illness is one of those risks that Insurers cannot really gauge.The one thing they do know is that they are continually getting claims.
As you say your own risk is low and within your control.
Check asbestos risks before doing anything.