What is the purpose of an attic?
What it does for the house
- Thermal buffer: a summer roof surface in Georgia gets far hotter than the air. The vented attic and the insulation on its floor keep most of that heat away from your ceilings.
- Moisture control: air moving through the attic carries off moisture that drifts up from the house, keeping the roof deck and framing dry.
- Structure: the rafters or trusses that hold up the roof, and often the ceiling, live there.
- Mechanical space: air handlers, ducts, bath fan ducts and wiring run through it.
- Storage: light storage on floored areas, as long as it does not crush insulation or block vents.
Vented vs conditioned attics
Most homes have a vented attic: insulation on the attic floor, with outside air moving through the space above it. Some newer or renovated homes have a conditioned or unvented attic, with insulation against the roof deck, which keeps ducts and equipment inside the home's thermal envelope. The residential code allows both. They are different designs, so know which one you have before adding vents or insulation.
What to check up there
Once or twice a year, look for stains on the decking, rusty nail tips, daylight where there should not be any, animal droppings, insulation that has settled or been disturbed, and bath fan ducts that have come loose. Problems caught from the attic are usually cheaper than the ones that show up on a ceiling. See roof ventilation basics and the Georgia roof maintenance checklist.