How to Route Home Dryer Ducts

Find the most direct route from the dryer location to the outside. Locate the dryer in the closest point to an outside wall, if you have that option; an ideal location is with the back of the dryer against an outside wall. Install a dryer in a house built without a special utility room in a basement, pantry or some other area that has an outside wall.

Put the dryer near a window or other access point if installing it in a basement. Place it with its back against an outside wall, if possible.

Measure the distance from the vent outlet on the dryer to the closest outside point with a tape measure to get vent pipe and plan the number of elbows or bends you will need to go from the dryer outside.

Run the vent pipe as straight as possible; every bend or elbow reduces airflow and is a potential location to trap lint, which can build up and create a fire hazard. Use smooth metal pipe, if possible, although flexible metal tubing is permitted in most building codes and may be easier to install.

Cut a hole in the outside wall with a reciprocal saw to fit the vent pipe, typically about 4 inches. Go through the wall above the foundation and below the floor in a basement or through the wall between studs on a slab foundation. Mount a cover plate in the hole to prevent rain and moisture from getting in from the outside.

Connect the vent pipe to the outlet in the dryer and use elbows to turn it as needed to reach the hole to the outside. Cut pipe as needed to fit with tin snips. Fasten joints with two layers of metal foil tape.

Keep elbows to a minimum, although in a basement there typically will be at least two, one from the dryer to turn the pipe upward and a second at the wall opening to turn it outside. If possible, use two 45-degree joints rather than one 90-degree angle. Support vent pipes at any locations where they might sag or bend to obstruct airflow.

Vent a dryer through the roof if you must install it in an interior room. Find the most direct route upward, cut a hole in the ceiling, go into the attic, cut another hole in the roof and run the vent pipe through the holes. Check before cutting to make sure you miss electrical wires or utility pipes.

Insulate the pipe where it goes through the ceiling and install a roof vent flashing and cap on the part above the roof. Check building codes for how high the vent must be above the roof surface; some require venting above the highest part of the roof.