If your roof is leaking from last winters snow and this has caused ceiling and insulation damage and contractors say there are 3 layers of shingles and the whole roof needs replacing is this covered?

You really need to ask your agent. If the roof is just worn out from age, it probably is not covered. If it was damaged in a storm, you usually have only a certain number of days to file a claim. They will probably say the interior damage is your fault for not reporting the damage to the roof. If it is covered, it is possible that the policy will only cover removal of two layers of shingles. But all the layers don't need to be replaced. The multiple layers were put on by someone trying to save a dollar by adding a layer instead of replacing one.