1919 house to vent or not

A homeowner with a 1919 house recently posted a question on a building science forum after noticing granule loss on the south-facing side of their roof. They're wondering whether poor attic ventilation, sun exposure, or both are causing it. They also mentioned that a second-story bedroom with an eaves closet on the south side and a west-facing window tends to run hotter than other rooms.

Looking at the attic, they found some insulation and what appear to be ridge vents (slots at the peak of the roof that let hot air escape), but no clear intake vents to let fresh air in from below — the kind of setup usually found at the eaves. The only possible opening they could identify was old, deteriorated wood shingle venting on a gable wall. A ridge vent without a matching intake often doesn't work as intended, since the system needs airflow moving in at the bottom and out at the top to actually cool the attic.

This is a single homeowner's question, not new research or a program announcement, so there's no rebate or deadline tied to it. But it points to a common issue in older houses: attics that look vented but aren't set up to actually move air, which can contribute to roof wear and hot upstairs rooms in summer. If your own house has ridge vents but no obvious intake at the eaves or soffits, it may be worth having your attic looked at, especially if you've noticed similar heat or shingle problems.