There are those people who want to install a roof dryer vent themselves. Here are some steps and guidelines for proper installation.
Your Installation Will Require Planning and Choosing a Location for the Vent
Assess your situation by looking at your attic, your rooftop, and your dryer location. Then choose the shortest, straightest route for the vent to run. Keep vents below 25 feet, if possible. As you calculate, remember that even though manufacturers say 60 feet, you need to subtract 10 feet for every 90 degree angle.
• Plan to have the installed vent hood 2 feet away from any other vent or chimney on your roof.
• Proper installation and sealing will be necessary so that your roof does not leak after the vent is installed.
• Depending on your situation, you may need to cut a hole in the ceiling above your dryer.
• Remember that Building Codes require a permit and inspection or you will be in violation of the law. Also, maximum footage and maximum bends must be within code specifications.
You’ll Need to Assemble Your Supplies:
• Carpenter’s pencil or chalk, a screwdriver
• Drill with ½” drill bit
• Reciprocating saw
• Flat crowbar
• 1-inch roofing nails, and 1 longer nail
• Tin snips, a pair of leather gloves
• Roofing tar and silicone roof caulk
• 4-inch metal duct pipe
• 4-inch metal duct elbow
• Duct clamps
• Metal foil tape
• Dryer roof vent cap
• Pipe insulation (this will be used for the attic portion of the vent pipe)
Installing Your Roof Dryer Vent
1. Depending on your particular circumstances, for the venting from your dryer to the attic you may need to slide one end of the duct elbow over your dryer’s exhaust vent and position the elbow with the open end facing the ceiling. Place your duct clamp around the connection and tighten with a screwdriver. Using a level, make sure the metal duct pipe goes straight up to the ceiling. Trace the location on the ceiling then cut the hole out just large enough for the duct to slide through. Measure and cut a length of duct pipe that will extend into the attic about 2 feet after it is connected to the elbow. Make the union secure with a clamp.
2. From inside the attic, you will now measure the length of duct pipe needed in order to reach the roof. At this point you will also determine the exact spot where the roof vent cap will be set. (You can put a nail through the roof from the attic side or from the outside—whichever works better for your situation.) Remember, you’ll need to stay 2 feet away from the chimney and other venting.
3. While still in the attic, use your chalk or pencil to mark around the opening of the bottom section of your rooftop dryer vent. Drill a hole on the line then insert the blade of your reciprocating saw and cut all the way around the outline.
4. Climb up onto your roof now, and cut away any shingles that may still be covering the hole. Use a flat crowbar to remove any nails that need to be removed. Spread roofing tar around the perimeter of the hole. Lift the shingles at the top of the hole so that you can insert the pipe portion of the vent cap down through the hole and also work the vent flashing under the raised shingles. Allow the shingles to fall back into place over the flashing then hammer some roofing nails through the shingles and flashing into the roof to secure the vent. The lower part of the flashing will rest on the shingles. You may need to cut some shingles directly under the flashing near the hole so that the flashing will sit flush with the existing shingles. Apply the roof caulk around the shingles, nails, and flashing to ensure a secure seal and also prevent moisture from leaking into the attic.
5. Go back inside your attic and use tin snips to cut your metal duct pipe to fit. Attach the dryer duct pipe to the dryer vent cap pipe. Using a screwdriver, secure the duct clamp around the pipe portion of the vent cap. Use metal bands and metal foil tape as necessary to fasten dryer vent pipe connections.
6. Wrap the attic portion of your dryer vent pipe with insulation in order to prevent condensation on the pipe. Fasten the insulation with metal foil tape. Insulating the pipe is especially important if you live in a cold climate, since cold temperatures will cause the hot air in the duct to condense. Condensation will allow lint to settle on the sides of the pipes and eventually block the pipe.