Seal the ceiling penetration so that the duct can expand in length as it heats up during use a standard roof boot such as you d use to flash a vent pipe would work.
Dryer vent thru attic.
Venting the dryer outside in cold weather wastes a lot of heat.
Not all dryers will allow for this so be sure to check the owners manual to ensure it can be vented in this manner.
Be careful you don t cut through any studs electrical wires or pipes in the process.
Sometimes such as in town homes or condos it s not possible to vent a dryer through a wall outside.
This causes the steam from your dryer.
This also means that you can t blow the dryer exhaust into the attic or the crawlspace.
The dryerjack in fact was born of extensive testing of the dryerbox and dryer ell and how they improve airflow.
Dryer vents should always be vented through the side of the house and not vented through the roof and ideally the exit should be fairly close to the ground.
If venting outside isn t an option you can vent the dryer out of the attic through the roof using a special roof vent to keep rain out.
These terminals need to be cleaned on a regular basis to prevent lint buildup.
Doing so would fill your attic with warm moist air that could rot the framing.
A dryer vent should be vented outside.
While elbows and length of run are important factors for efficiency and safety the exhaust termination is often the biggest restriction point.
In these cases it may be necessary to vent your dryer through the attic.
Keeping a clean dryer vent is much easier when you can safely reach the exit.
A vertical dryer vent is typically a problem because it acts as a moisture condenser.
In real world tests inefficient roof terminations would often all but negate the improved efficiency of eliminating restrictive elbows.
You must terminate your dryer vent outside the building according to section m1502 of the irc.
Vent the dryer with 4 in.
Continue the ductwork horizontally through the attic to the closest exterior wall.
When venting dryers for long distances use rigid metal pipe with as few elbows as possible.
When bath fans and clothes dryers vent through the roof they melt a bunch of snow.
Often going straight up through the roof is the shortest route.
The sheet metal duct is cooled by the outside air in the attic.
Clothes dryers should be vented through the side of the house preferably within reach from the ground.
To make the dyer more efficient you can buy an inexpensive heat diverter and install it in the exhaust duct of electric dryers only not gas dryers you ll save about 50 worth of heat per load in the winter.