Dryer Fire Prevention in Apartment Buildings

Dryer fire prevention in an apartment building comes down to lint and airflow. Most dryer fires start when lint builds up in the dryer or its exhaust and the hot air has nowhere to go. Keep the exhaust path short, metal and clear, replace plastic or foil transition ducts, and give tenants a few plain rules about lint screens and what not to put in a dryer.

The rest is about who controls which part, because in a multifamily building that's split between you, the super and the tenant.

What actually starts dryer fires

The leading cause is a dryer that wasn't kept clean. The U.S. Fire Administration's report Clothes Dryer Fires in Residential Buildings (2008-2010), published in August 2012, estimated about 2,900 residential dryer fires a year reported to U.S. fire departments, causing an estimated 5 deaths, 100 injuries and $35 million in property loss annually. Failure to clean was the leading factor contributing to ignition, at 34 percent. Dust, fiber and lint (28 percent) and clothing not being worn (27 percent) were the items most often first ignited.

Those are the most recent figures USFA has published on the topic, and they're over a decade old, but the mechanism hasn't changed. Lint comes off every load. The lint screen catches most of it. The rest goes into the dryer's housing and down the exhaust, and it settles wherever the air slows down: at a kink, a long horizontal run, a crushed section behind the machine, or a clogged exterior hood.

Less air leaving means more heat staying in the drum. The dryer runs longer to dry the same load, the heating element or burner works harder, and the lint sitting nearest the heat is the fuel.

The same report found dryer fires were more common in fall and winter, peaking in January. The report suggests heavier winter clothing and less line-drying as likely reasons. For a building, the practical takeaway is to check vents before the heating season, not after.

Plastic and foil transition ducts have to go

The short duct that connects the back of the dryer to the wall is the part most likely to be wrong in an apartment, and the easiest to fix. The U.S. Consumer Product Safety Commission's guidance on overheated clothes dryers says to replace plastic or foil, accordion-type ducting with rigid or corrugated semi-rigid metal duct. It notes that most manufacturers specify metal duct and that flexible plastic or foil duct traps lint more easily and is more likely to kink or get crushed.

That last part is the apartment problem. In-unit dryers in NYC are often squeezed into closets and kitchen alcoves, pushed back tight against the wall, and the soft foil duct behind them gets folded flat. You can't see it without pulling the machine out.

Make it a rule for every in-unit dryer you control:

• No white vinyl or plastic duct, anywhere.
• No thin foil accordion duct. Use semi-rigid or rigid metal for the transition.
• The transition should be as short as the installation allows, without sharp bends or a crushed section.
• Pull each dryer out and look whenever a unit turns over.

The full exhaust run, beyond that transition, has to meet the NYC Mechanical Code's clothes dryer exhaust rules (Section 504) and the dryer manufacturer's installation instructions. If you're not sure an existing run meets them, have the installer or a licensed contractor check before you put a new dryer on it.

Tenant habits that raise the risk

A good vent can still be undone by how the dryer gets used. The habits that matter most are simple, and tenants rarely know them.

Cleaning the lint screen every load is the big one. CPSC recommends cleaning it before or after each load. A screen that's been skipped for a week cuts airflow before the vent is even involved.

Overloading is the second. A drum packed tight with towels dries slowly, and long cycles mean more heat and more lint. Two medium loads are safer than one stuffed one.

Then there's what goes in. CPSC warns about clothes soiled with volatile chemicals such as gasoline, cooking oils, cleaning agents and finishing oils or stains: wash them more than once, and preferably hang them to dry. If a dryer must be used, CPSC says to pick the lowest heat and a cycle with a cool-down at the end, and not to leave dried clothes sitting in the dryer or piled in a basket. Kitchen rags and towels used to wipe up oil are the everyday version of this. Many dryer manuals also warn against foam rubber and rubber-backed items such as bath mats, so tell tenants to follow the care label and the dryer's manual.

Last: don't run the dryer when nobody's home or overnight. That's a rule of thumb, not a statistic, but a fire caught early in an occupied apartment is a different event from one that's had two hours alone.

A tenant notice you can adapt

Tenants read a short notice. They skip a long one. Something like this works on a laundry-room wall, in a move-in packet or under the door of every unit with an in-unit dryer:

Dryer safety in this building. Clean the lint screen before or after every load. Don't overload the dryer. Don't dry items stained with oil, gasoline, paint thinner or cleaning chemicals, and don't dry foam rubber or rubber-backed mats. Don't leave the dryer running when you go out or go to sleep. If clothes take much longer than usual to dry, the dryer feels very hot, or you smell burning, stop the dryer and tell building management right away. In a fire, get out, close the door behind you and call 911.

Adjust the last lines to your building's reporting process, and translate it into the languages your tenants read.

Signs a dryer is heading toward a fire

Long drying times are the clearest early sign. When a normal load takes two cycles, the airflow is restricted somewhere, at the screen, in the dryer, in the transition or in the building's run. CPSC lists clothes still damp at the end of a typical cycle as a sign the screen or exhaust duct may be blocked.

Other signs worth a work order: the top or sides of the dryer are very hot to the touch, the laundry room or closet gets noticeably hot during a cycle, a burning smell, lint collecting around the back of the machine or at the door seal, and an exterior hood flap that doesn't open while the dryer runs. Any of these means stop using that dryer until someone has looked.

How often the vents themselves should be cleaned, and how to schedule that across shared runs and roof terminations, is covered in our note on dryer vent cleaning in multifamily buildings.

What to do after a dryer fire

Call 911 for any dryer fire, even one that seems to be out. Lint packed into a duct can keep smoldering where nobody can see it, and in a multifamily building that duct may run through walls or a shared shaft. Let the fire department decide that it's out.

After that, the order of work is roughly:

1. Don't run that dryer again, and in a shared laundry room take any dryers on the same exhaust out of service until they've been checked.
2. Document it: photos of the machine, the area behind it and the duct, the time and what the tenant or super saw. Notify your insurer.
3. Have the whole exhaust path inspected and cleaned, not just the transition. A fire in the drum is often a sign of lint in the run.
4. Decide on the dryer itself. A unit that had a fire inside usually isn't worth repairing; heat damage to wiring, the drum seals and controls can be hard to see. If you replace it, fix the transition duct then; a gas dryer needs a licensed plumber's hookup.
5. Look at the other dryers in the building. If one vent was bad, the others were probably installed by the same people at the same time.

For how a burning smell ranks against other appliance calls, see our note on which breakdowns are emergencies.

When a dryer needs a technician

If a dryer in one of your units is taking too long, running hot or has a plastic or foil duct behind it, open a work order with the building, the unit and what the tenant noticed. Requests through the booking page are scheduled within 24 hours, and the service call ($145 and up) covers the visit and on-site diagnosis, with the repair quoted for approval before work starts. Our washer and dryer repair page lists the dryer faults we see most often.