No, a dryer should not be vented through the roof. It should go out through a wall or the eve of a roof. It should have a cap on the end with a flapper, so that animals cannot get in.

I have installed some dryer vents in attics and directed them out the eve. To get to the attic they had to go up approx 9 feet, then turn horizontal and go another 10 or 15 feet. They clogged up with lint, so I installed a booster fan made just for such applications (fantech dbf110a I think) but they need to be cleaned out every six months, and they are usually neglected.

Nearly every single home in my subdivision (and it is a large one built around a golf course) has the dryer vented through the roof.

Now is it a good idea? That's highly debatable. Ours goes from the center of the house straight up to the attic and then it takes a 45 degree turn to go out the roof on the other side. It's about a 20 foot run.

We had to have professionals come out and clean it and had a different type of roof vent installed that wouldn't catch so much lint (as I've noticed several people have done) since the builder put on metal flap types with a mesh covering on them. With it so high on the steep roof, no one's going to get up there to clean it out very often.

I haven't seen it in a manual in some time but many of the manufacturers used to say to never vent straight up higher than 15 feet.
I generally see problems with drying when the vent is going up through the middle of a 2 story house. These runs are around 25+ feet straight up and the dryer just can't push air that high. The blower has to fight the atmospheric weight of a column of air pushing down (14.7 psi at sea level). I have seen the inline fan tech blowers help in these situations.

If you live in a cold climate, another potential problem is with condensation. If any of the hot humid air in the duct cools below the dew point you'll end up with water heading back into your dryer. Insulating the duct could help this, but why take a chance.

Not ideal but it can be done. Mine is - single story 9 ft. ceiling. No problems.

Thanks for all the replies. I live in the south, it's a one-story house with 8 ft. ceilings. The dryer would be stacked on a washer, so I could go up about 4 feet through the ceiling, then horizontal about 13 ft. to an eave. That sounds better/easier than going through the roof and having to deal with shingles, leaking, etc.

Am I thinking right?

Yes, you are. Requirements: >Dryer vent must not exceed 25 feet. Each elbow counts as five feet. This is because of the sharp turn and the restriction it causes. Try to get long-radius elbows made just for dryer vents. These are relatively new on the market. >Do not use vinyl flexible vent at the dryer connection. Instead, install a recessed box in the wall and use a semi-rigid aluminum flexible vent connector. >No screws may be used to secure the pipe joints; only foil tape. There must be nothing in the airway which might collect lint. Get an all weather foil tape, 2 mil thick. Most contractors just use what the wholesaler stocks, not realizing (or caring) whether it will stay stuck over the years. >Ensure that male pipe ends are not re-crimped by the installer. Installers often make this end smaller than it needs to be instead of using a little patience to gently squeeze it to match the next section. >Do not protect the outlet with any kind of screen. Flap yes, screen no. >After installation, go outside and catch some lint. If it is hot and dry, you should be in good shape. If there is any moisture in the lint, you will have to have to clean the pipe every once in a while. Also feel the air stream. You should feel at least a gentle breeze from 3 feet away. >The box and the elbows are available from dryerbox.com.

If everything is installed correctly, lint in the pipe should be dry 15 feet away from the dryer. This is in linear pipe feet. Here the elbow does NOT count as 5 feet. If the pipe run is less than 15 feet, the lint will be moist at the outlet. If it is dry, and the run is less than 15 feet, this indicates that the lint has probably swirled in the stream before exit, and that you may have some obstruction in the line. Please bear in mind this is just a guideline, and by no means should it be accepted as gospel.

Yes you can. You can also put a 25' exhaust Pipe going straight Up on the back of your car or truck.

Both will work. But I doubt any contractor would do either of those to his OWN House or Truck.

Pushing any thing straight UP takes energy. Energy your dryer might not have to spare.

Your dryer will not be as efficient, break sooner and may cause a fire.

Allot of installers know they just have to make it work.
And they don't have to live there.

90% of Condo dryers are vented through the roof.

Yes, because never through eaves that are vented for attic flow.

If I may add to the questions :-). We are tearing down a wall and redesigning our laundry room. With that being said I want to try to install a mud sink and put my washer and dryer beside each other. Previously the dryer was vented in our garage which makes the floor in garage very slippery during winter months. I would like to vent it through the roof or eve!? My question is...would this make the clothes take longer to dry/run up energy bill? Is this safe? How does rain stay out of vents? Would this be a big expense? The shortest way to venting "outside" is in the garage . I am going to attach a photo as to how I would like my washer and dryer and mud sink to be to give a better idea as to what I want.

From what I read you are allowed to go through the roof however keep in mind maximum length is 35 ft from the dryer and if you use a 45 degree elbow it is 2.5 ft less to bring it to 32.5 ft and a 90 degree elbow if 5 ft less which is then at 30 ft cause every off set is concidere a constriction now i wouldn’t personally exhaust out the roof cause you would need the proper vent hood to restrict rain and moisture from going back in the vent which if any moisture goes in can create lint gathered by the moisture then when the lint that you thought was getting out was collected by moisture then the dry lint that’s been trapped in the vent can cause a fire and also on another note if you exhaust out the roof regardless of the vent being waterproofed you can still get condensation mostly in the fall and winter

Yes u can vent a dryer threw a roof just use the proper exit vent for roofs.. any one who says u can't has no clue to what that are talking about.

Roof venting can be done but it requires more maintenance and is the worst method if there's an alternative route.

My dryer vents through the roof. The aluminum tube extends to within a few inches of a roof vent. I've had no issues. I use a leaf blower to clear the vent of lint every couple years.

leaf blower??? how does that work? disconnect at the dryer and blow out?

Yes. Move the dryer, disconnect the ducting from the wall, aim the blower into the wall opening. May also need to blow it from the exterior, which is messy in the house.

There are currently no dryer vent covers for the roof where the damper would seal the dryer vent opening tight. All of the existing dryer vent covers for the roof have gaps around the damper which allows hot/cold outside air travel down the dryer vent and to your dryer and to your home. Shame! Shame! Shame on the engineers who ctreated such horrible dryer vent covers!