How to inspect the attic for leaks, pests and blocked vents
Once or twice a year, use this attic inspection checklist: go up with a flashlight and check the roof deck around chimneys, vents and valleys for stains. Look for droppings, nests and chewed wires, confirm that soffit vents are clear, and trace each bath fan duct to the outdoors. Stop if you see vermiculite or knob-and-tube wiring.
What to look for in an attic
Your attic can show problems that the ceilings below it are hiding. Roof leaks can soak into insulation long before a stain shows in a room. Pests move in through small gaps and stay out of sight. University of Georgia Extension puts attic checks on its spring and fall list. Fall is especially useful, before the weather turns.
You're checking five things:
- The roof deck and the framing, especially around roof penetrations
- Flashing at plumbing stacks and chimney or flue shafts, seen from below
- Signs of pests
- Airflow at the eaves
- Exhaust ducts, which must end outdoors and not in the attic
Attics can hold hazards you shouldn't disturb, so look before you step in. Stay on the framing or on boards that are secured. Ceiling drywall won't hold your weight. Don't crawl over or move wires, and keep your head clear of nails coming through the roof.
How to inspect an attic, one step at a time
- Pick a dry, cool morning
Attics get hot. Bring a bright flashlight, a dust mask, gloves and your phone, and tell someone you're going up.
- Pause at the hatch
Scan the insulation and wiring first. If you see vermiculite or knob-and-tube wiring, go back down.
- Inspect the roof deck
Follow the underside of chimneys, vents, skylights and valleys. Touch any stain to see if it's damp.
- Look for pests
Check along the eaves and around gable and roof vents for droppings, nests and torn screens.
- Check the eaves
Make sure insulation isn't covering soffit vents.
- Trace the ducts
Follow each bath and kitchen fan duct until it leaves the house through the roof or a wall.
- Take photos and log them
Save dated photos of any stains so you can compare them next time.
Attic inspection checklist and what each find means
| What you see | What it probably means | What to do |
|---|---|---|
| Dark stains on the roof deck | Past or current leak | Check again after a heavy rain. Damp means it's active, so call a roofer. |
| Daylight around a pipe or chimney | Gap in flashing or roofing | Call a roofer. |
| Daylight at the eaves | Soffit vents, which is normal | Keep them clear. |
| Musty smell, mold on wood or insulation | Moisture problem | Find the source. See the size rule below. |
| Insulation packed against the soffits | Blocked airflow | Pull it back gently, and ask about baffles. |
| Bath fan duct loose or ending in the attic | Moist air venting indoors | Have it redirected outside. |
| Droppings, nests, tunnels in insulation | Rodents or other pests | Clean up safely and seal entry points, or hire pest control. |
| Chewed wires | Fire risk | Turn off that circuit if you know it, and call an electrician. |
| Thin or crushed insulation | Reduced R-value | Measure it against your climate zone's target. |
Attic inspection finds to leave alone or hand to a pro
Some finds mean you should stop and leave things alone.
- Vermiculite: pebble-like gray-brown or silver-gold insulation. A mine in Libby, Montana, supplied over 70% of US vermiculite from 1919 to 1990, and its ore was contaminated with asbestos. EPA says to assume it contains asbestos, leave it undisturbed, keep trips short, store nothing up there and never remove it yourself.
- Knob-and-tube wiring: old wires on ceramic knobs. Call a licensed electrician before any attic work.
- Sagging, soft or rotted framing: call a licensed contractor or structural engineer. Don't remove attic flooring either, since it may be doing a structural job.
- Heavy mold: EPA says you can usually handle areas under about 10 square feet. Bring in a professional for anything larger.
For rodent mess, CDC says not to sweep or vacuum, because that can throw virus particles into the air. Open the space to air for 30 minutes if you can, and leave while it airs. Wear rubber or plastic gloves. Soak droppings and urine with a mix of 1.5 cups of bleach per gallon of water, or an EPA-registered disinfectant, and let it sit for 5 minutes or as the label directs. Wipe up with paper towels, bag them and wash your hands. For a heavy infestation, hire a pro.
Fix roof leaks and pest problems before anyone adds insulation. New insulation over a wet deck hides the damage and makes it worse.
How often to inspect your attic, and other questions
How often should you inspect your attic?
University of Georgia Extension includes attic checks in its spring and fall upkeep. Look again after a major storm, or if you notice a musty smell or noises overhead.
Is a stain in the attic always an active leak?
No. It may be an old leak that was already repaired. Touch it, and check again after a heavy rain. If it's damp or has grown, call a roofer.
How do I know if my attic insulation contains asbestos?
You can't tell by looking. Vermiculite is the main concern, so EPA says to assume it contains asbestos and leave it alone. Contact your state health department or a licensed asbestos professional about testing.
Sources: basc.pnnl.gov, CDC, EPA, content.ces.ncsu.edu, fcs.uga.edu
General guidance for U.S. homes, not professional advice. For gas, electrical and structural work, call a licensed pro.