Most attic problems and most roof problems share the same root cause: heat that isn't staying where it belongs. Warm, moist air rises into a poorly sealed attic, warms the underside of the roof deck, and melts the snow sitting above it. That meltwater runs down to the cold eave and refreezes — that's an ice dam, and it's the attic's fault as often as the roof's.
So when we're up in your attic checking insulation and ventilation, we're also looking at what's happening to the roof above it — moisture staining, past ice dam damage, ventilation that's aging the shingles faster than it should. If everything checks out, we'll say so. If it doesn't, you'll hear it plainly, with no pressure to act on it today.
Insulation depth is only half of it, too. Can lights, plumbing stacks, and attic hatches all give heated air a way to bypass the insulation entirely — gaps matter as much as depth. We check both, because insulation without air sealing isn't enough.