Poor ventilation is **the most common defect we find on Houston roofs**, and it quietly costs you both roof life and cooling dollars.
Signs your attic isn’t breathing:
– **An attic that’s brutally hot** in the afternoon — well above outdoor temperature rather than close to it.
– **Upstairs rooms that never cool down** while downstairs is comfortable.
– **Cooling bills climbing** without a rate change.
– **Rusted nail tips** visible on the underside of the decking, which means condensation.
– **Curling or blistering shingles** on an otherwise young roof, cooked from below.
– **Musty smell or visible moisture** on insulation.
Ventilation has to be **balanced** — intake at the soffits and exhaust at or near the ridge. The most common mistake in Houston isn’t too little exhaust, it’s **blocked intake**: insulation pushed over the soffit vents during an attic upgrade. Exhaust with no intake pulls conditioned air out of your house instead of moving attic air.
The general target is 1 square foot of net free vent area per 150 square feet of attic floor, split roughly evenly between intake and exhaust.
It’s inexpensive to correct during a re-roof and expensive to ignore.