Smelly attics are often a sign of larger problems. Getting rid of the smell is important. Determining the cause and ensuring it does not return are more important.
Causes Of Smelly Attics
Awful attic smells are usually the first sign that something is wrong. Clean, dry, and well-ventilated attics have very little odor. Leaks, condensation, and humidity all cause mold in attics. The causes of attic smell–mold, pests, and rot–are also health risks.
Mold and Mildew
The musty smell of mold is usually the first sign of an attic problem. Any type of attic moisture acts as an instigator for mold growth. The attic is usually warm and contains abundant food sources such as dust, wood, and stored boxes, fabric, and paper.
Wet fiberglass insulation stinks. So does wet cellulose insulation. It just takes a little longer. Mold growing on the dust that insulation traps mixes the sweetish insulation smell with the musty smell of mildew. Not appealing.
Rodents like rats, squirrels, and mice in the attic make a mess, compromise insulation, and produce feces and urine–food sources and moisture for mold. They also die and decompose producing a sulfurous odor. Even insect colonies cause smells and promote mold growth.
Decay and Rot
Moisture and mold growth eventually lead to rotting framing. Not only does rot smell bad, it causes structural damage. Anything organic stored in the attic is also subject to mold and rot–adding to the smells and damage.
Getting Rid Of the Attic Smell
Getting rid of attic smells, finding the cause, and fixing the problem should follow an orderly process.
Ventilate the Attic
Working in a smelly attic can be uncomfortable and unhealthy. Set up a box fan to blow out the odor. Open windows–if they exist. The fan will blow most of the odor out of windows and attic vents. Close the attic door/hatch to keep the smell from the home’s living area.
If you have asbestos insulation, do not set up a fan. Asbestos fibers will become airborne and can be breathed in. Asbestos removal is best left to professionals.
Find the Source
Conduct a thorough inspection of the attic. Mold in one spot or one dead rodent is usually not the sole source of really foul smells. The problem may be years old. Until it gets bad enough or big enough to produce noticeable odors. Attics should be checked yearly but many go for years without anyone looking at them.
Remove the Problem
All wet or moldy or pest-infested insulation has to be removed and disposed of. Wet moldy stored items have to be removed and thrown out or thoroughly cleaned and repacked. All moldy framing, drywall, ducting, and pipes have to be sprayed with mold killer such as bleach. Plastic containers also can have mold spores that need to be bleached clean.
Make sure that all moldy wood gets checked for rot. Rotted structural wood needs to be replaced or reinforced.
Place at least four open boxes of baking soda in the attic to absorb any remaining odors. Spread them throughout the attic.
Preventing Attic Smells
Moisture is the attic’s worst enemy. Make sure attic smells do not return.
- Roof. Patch all leaks.
- Ventilation. Ventilated attics require one square foot of venting for each 150 square feet of ceiling area. Half in the soffits; and half near the ridge. Install more if necessary.
- Humidity. Seal all gaps, cracks, and penetrations from the living area to keep warm humid air out of the attic.
- Pests. Mice can get through a hole the size of a dime. Seal–or install metal screens over–all holes to the exterior.
Hire a Professional
Getting rid of attic smells is not a project everyone wants to take on. Fortunately, many companies offer the service. Cleaning. Insulation and pest removal. New insulation installed. Roof repairs. Pest control. Find one that offers free inspections and written quotes.