As someone who owns a washer and dryer, you should always vent your dryer to the outside. Venting dryers into an attic or crawl space violates building codes in most municipalities, is dangerous, and can lead to several problems.

    When they run, dryers push out hot, moist, and lint-filled air, which is not something you want in your attic. Excess moisture can lead to the formation of mold, and a buildup of lint is a fire hazard. 

    Check out our video on dryer vent safety for more information, but below, we outline more details of why venting your dryer into your attic is a bad idea.

    Potential Issues with Venting a Dryer in the Attic

    Directing your dryer into an attic goes against most building codes and creates a serious fire hazard.

    Dryer lint accumulates wherever air comes out. As it builds up, it grows increasingly flammable. A spark from the dryer could easily ignite it and start a fire.

    Venting moisture into the attic also causes moisture damage and encourages mold growth in your home, not just the attic space. Condensation can lead to rot and decay in the home’s attic framing, insulation, and drywall. Adding moisture to the space prevents the ability to maintain an ideal humidity level for your home, negatively impacting indoor air quality (IAQ).

    Solutions for Proper Dryer Venting

    Venting your dryer directly outdoors through the wall or roof is the best solution. When done correctly, it puts lint, moisture, and exhaust outdoors, where it cannot cause problems. Exterior venting also improves dryer efficiency and can lower your energy bills.

    If your laundry room has access to an outside wall, cut a 4-inch diameter hole and install a standard dryer vent hood with a damper. Be careful not to cut through electrical wires, plumbing pipes, or structural framing when cutting the hole. Wear safety goggles for eye protection.

    If an exterior wall isn’t accessible, you can vent the dryer through the roof instead. Use a dryer vent designed for roof venting, which seals when the dryer isn’t running. Position the vent on a sloped roof surface to allow moisture to run off. Sometimes, you may need a dryer vent extension to meet building code requirements and achieve proper appliance operation.

    Proper Dryer Vent Installation

    Proper dryer vent installation ensures lint and moisture vent to the outdoors. When running a dryer vent, use smooth 4-inch diameter rigid metal ductwork. Home repair stores sell flexible metal and vinyl vent hoses. While easy to work with, they trap lint and are unsafe. Instead, join rigid metal sections together using metallic HVAC tape to seal joints — not screws, which catch lint.

    Follow the maximum vent length for your dryer model, usually under 35 feet. Use as few elbows as possible since each bend reduces airflow. Longer vents over 25 feet may need a duct booster fan installation to maintain air velocity.

    Periodically detach dryer ducts to clean them. Lint can still accumulate even when vented outside. A clean vent is safer and allows proper airflow. Many duct cleaning professionals provide this service if you need help.

    Dryer Vent Safety Tips

    Here are a few dryer vent safety tips to keep in mind:

    • Inspect your outdoor vent hood regularly to ensure it is not blocked. Clogged vents are a fire hazard.
    • Clean trapped lint from the vent system at least once per year. Detach the vent and brush out the entire length.
    • Never use vinyl, plastic, or foil vent ducts. You need rigid metal ductwork to prevent lint buildup.
    • Do not join dryer duct sections with sheet metal screws. Use metallic HVAC tape only to seal joints smoothly.
    • Avoid crushing or kinking the dryer vent during installation because it restricts airflow.

    Properly venting your dryer to the outdoors can prevent dangerous lint buildup and keep your home safe. 

    So, Is Venting a Dryer in the Attic Safe?

    Home experts always recommend venting a dryer outside a home and never into an attic. A vent in the attic poses serious fire and moisture dangers, violates building codes, and can cause attic damage over time. With proper venting to the exterior, dryers can operate safely for years to come.

    FAQs About Venting Dryers

    How do I clean my dryer vent?

    Detach the dryer vent where it connects to the dryer and use a dryer vent brush to clean lint from the entire length of ductwork — vacuum loose lint with a hose attachment. Clean your vents at least once a year. If you’re uncomfortable with this process, ask your HVAC contractor if they provide this service when performing your annual HVAC tune-up.

    Can I vent my dryer into the garage?

    No, venting a dryer into the garage is dangerous, just like venting into the attic. Always exhaust dryers outdoors.

    What are the signs of a clogged dryer vent?

    Signs include clothes taking longer to dry, hot air escaping the dryer cabinet, and lint accumulating around the vent hood outdoors. A professional can confirm if there is an obstruction in your vent.

    What is the maximum length for a dryer vent?

    Check your owner’s manual, but do not exceed 35 feet in total developed length. Calculate length, adding 5 feet for each 90-degree elbow. Maintain velocity with rigid metal ductwork.

    How do I install a dryer vent through the roof?

    Use a vent designed for roof venting. Install on a sloped roof surface. Make sure to seal around the pipe penetration through the roof deck using silicone caulk.

    Can I vent two dryers together?

    No. Each dryer needs its own 4-inch diameter vent from the machine to the outlet. The only exception is a common manifold at the very end.

    Editorial Contributors
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    Elisabeth Beauchamp

    Senior Staff Writer

    Elisabeth Beauchamp is a content producer for Today’s Homeowner’s Lawn and Windows categories. She graduated from the University of North Carolina at Chapel Hill with degrees in Journalism and Linguistics. When Elisabeth isn’t writing about flowers, foliage, and fertilizer, she’s researching landscaping trends and current events in the agricultural space. Elisabeth aims to educate and equip readers with the tools they need to create a home they love.

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    Sabrina Lopez


    Sabrina Lopez is a senior editor for Today’s Homeowner with over 7 years of writing and editing experience in digital media. She has reviewed content across categories that matter to homeowners, including HVAC services, home renovations, lawn and garden care, products for the home, and insurance services. When she’s not reviewing articles to make sure they are helpful, accessible, and engaging for homeowners like herself, Sabrina enjoys spending time with her family and their two parrots.

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