Why is my attic so hot?
Short answer. Attics get hot because the sun heats the shingles and roof deck, which radiate heat down into the attic air, and in a Georgia summer that can push attic temperatures far above the outdoor temperature. Some heat is normal; it becomes excessive when intake vents are blocked, exhaust is undersized or short circuited, or dark shingles and leaky ducts add to the load.
Normal vs a problem
Even a well ventilated Georgia attic can be very hot on a July afternoon. Ventilation trims the peak and helps the attic cool faster in the evening. It becomes a problem when the attic stays hot late into the night, the deck looks discolored, upstairs rooms stay warm, or insulation shows dark streaks where air is leaking through it.
Common causes of excess heat
- Blocked intake: insulation over the soffit vents, or vented panels over solid wood.
- Too little exhaust, or exhaust short circuited by mixed vent types.
- Dark shingles absorbing more solar heat.
- No radiant barrier on the underside of the deck.
- Leaky ducts or an air handler dumping heat or air into the attic.
- Thin insulation, which does not heat the attic but lets its heat reach your ceilings.
What helps
- Restore intake with baffles and clear soffit vents.
- Balance exhaust with one system near the ridge.
- Air seal and add insulation on the attic floor.
- At replacement time, consider lighter or more reflective shingles if your HOA allows.
- Have ducts sealed and insulated by an HVAC contractor.
Read attic heat and shingles and best shingle colors for Georgia heat.