Dryer vent on an inspection report: replacement cost

What does a dryer vent finding cost to fix?

The fix for a dryer vent finding is a cleaning, a new metal duct, or a reroute outside, depending on what the report names. Fixr puts a professional cleaning at $100 to $200. Homewyse puts a new dryer vent at $192 to $380. Ask the seller to correct it, and back the request with a written bid from an installer.

Key takeaways

• The U.S. Fire Administration names failure to clean as the leading factor in dryer fires, not the duct material.
• A screen over the outside end is wrong because it traps lint; the code calls for a hooded damper.
• Name the duct material and exit point in the request, so a cleaning alone does not count as the fix.

How much does dryer vent replacement cost?

The price depends on the job the finding calls for.

Kept prices every line of an inspection report for $79, usually under 4 hours, and marks the ones that need a professional quote. Your installer's written bid, for your house and your vent path, replaces every figure in this table.

Do home inspectors check dryer vents?

Yes. The International Association of Certified Home Inspectors (InterNACHI) tells its members that "restrictions should be noted in the inspector's report" because blocked airflow is a potential fire hazard. It also says an inspector will not be able to confirm the vent meets the dryer maker's instructions or local code. Your report flags what the inspector could see. It does not certify the rest of the run.

What InterNACHI tells inspectors to flag:

• Flexible, ribbed duct used where the code calls for smooth metal, as a potential fire hazard.
• A vent that ends in the attic or crawlspace instead of outside.
• A run that is too long or has too many bends.
• A screen over the outside end, which catches lint.

If the report also flags mold where the vent ends, read mold, radon and asbestos findings on an inspection report next.

How serious is a dryer vent finding?

The risk is fire. A U.S. Fire Administration report on 2008 to 2010 data found: "An estimated 2,900 clothes dryer fires in residential buildings are reported to U.S. fire departments each year and cause an estimated 5 deaths, 100 injuries, and $35 million in property loss." The same report names "failure to clean" as the leading factor in those fires.

The Consumer Product Safety Commission (CPSC) explains how it happens: "Lint can block the flow of air, cause excessive heat build-up, and result in a fire in some dryers."

A vent that ends indoors adds a water problem. A dryer puts out about a gallon of water per load, according to the Department of Energy's Building America Solution Center. Dumped into an attic or crawlspace, that moisture can feed mold and wood rot. InterNACHI says the vent must end outside the house.

If the dryer runs on gas and you smell gas at a showing or walk-through, leave the house and call the gas utility or 911 from outside. Then have a licensed gas professional check the dryer before anyone runs it.

What are the dryer vent rules?

InterNACHI quotes the International Residential Code (IRC), section M1502, and the Building America Solution Center gives the duct spec in plain terms.

• Duct: rigid or semi-rigid metal with a smooth inside, 4 inches across, per the Solution Center. PVC pipe is not allowed.
• Length: at most 35 feet from where the connector meets the wall duct to the outside cap, less 2.5 feet for each 45-degree bend and 5 feet for each 90-degree bend. A longer run is acceptable if the dryer maker's instructions allow it.
• Connector: the flexible piece from the dryer to the wall is one length of 8 feet or less, listed to UL 2158A.
• End: outside the house, at least 3 feet from any opening, with a backdraft damper and no screen.

CPSC's advice for plastic or foil duct is plain: replace it with rigid or semi-rigid metal duct. The one exception the Solution Center makes to venting outdoors is a ventless dryer with a condensate drain. Which code edition your town has adopted is a question for your local building department.

Who fixes a dryer vent, and can you get a bid in time?

Fixr describes a cleaning as typically a one-person project that takes less than an hour. Ask the bidder to write down the duct material, the length and bends, and where the vent will end, so the bid matches the report line. How to get repair estimates during the inspection period covers getting that bid before your deadline.

What should you ask the seller for?

Ask for the correction the report names, priced by your bid. You have two ways to word it:

• A repair by an HVAC installer, with the duct material and exit point written into the request, and a paid invoice before closing.
• A credit equal to your written bid, if you would rather pick the installer yourself.

Describe the scope, not the symptom. "Fix the dryer vent" leaves room for a cleaning alone. A request to replace the foil duct with metal duct and reroute the exhaust from the attic to an outside wall cap gets the job the report calls for. What to ask for after a home inspection shows where this line fits in your list, and the buyer repair request letter template gives the wording around it.

What if the seller says no?

You can switch to a credit, accept the house and pay for the fix yourself, or cancel if your inspection contingency allows it. If you close with the vent as it is, have it corrected before the first load of laundry. When to walk away after a home inspection covers which findings are worth leaving over. Your contract sets the deadlines and terms, so confirm them with your agent or attorney.

How often should dryer vents be cleaned or replaced?

The Building America Solution Center says to have a professional technician clean the exhaust duct at least once a year. It says to replace the duct when it is damaged or made of vinyl, nylon or foil. CPSC lists the warning signs: clothes still damp after a typical cycle, or drying that takes longer than normal.

Upload your inspection report and put the installer's bid next to a price for everything else on it.

Sources

• U.S. Fire Administration, "Clothes Dryer Fires in Residential Buildings"
• CPSC, "Overheated Clothes Dryers Can Cause Fires," Publication 5022
• InterNACHI, "Dryer Vent Safety"
• Building America Solution Center (U.S. Department of Energy), "Proper Clothes Dryer Venting"
• Fixr, "How much does it cost to clean a dryer vent?"
• Homewyse, "Cost to Install a Dryer Vent"