How to extend dryer vent under a deck?

[sbennett61]

I have recently completed a second-story deck on the back of our house. I plan to turn the space underneath it into a screened-in porch. This will include a ceiling of some sort hanging from the deck joists.

Our dryer currently vents just under the deck. I need to somehow extend the vent to the edge of the deck (about 10 feet). THis will be done inside the joist cavities under the deck. I live in the midwest, so I have both rain and freeezing temperatures to deal with.

My question: What sort of vent pipe should I use?
- 4" solid aluminum
- 4" galvanized
- 4" flexible aluminum

I want something that will stand up to the elements as much as possible.

Thanks!

[HayZee518]

use the solid aluminum and very sticky duct tape. also, use three self tapping 1/2" long screws at each joint.

[pushkins]

also make sure you support the pipe extension with steel strapping and if possible on a very slight upward direction (very slight), when venting from driers passes through exposed and in deck joists is considered exposed , the hot air in winter will want to condense rather quickly. You don't want to see any ugly marks on your deck ceiling, so no sags in your pipe and a very slight upward direction would help keep the warm air moving out.

[Hube]

use the solid aluminum and very sticky duct tape. also, use three self tapping 1/2" long screws at each joint.

************************************************** ********Just use plain aluminum pipe, but DO NOT use any screws!!! Screws will eventually lead to lint clogs. Properly applied good tape will do.
For supporting the pipe (if necessary), use "draw band" type hangers ,these "draw band" type hangers not only support the pipe but will also eliminate any chance of separation of any joints by tightly gripping the joint with no penetration to the pipe.

[LazyPup]

I would suggest the solid aluminum pipe, however I must take an exception with both Hayzee and Pushkins on this one.

Tape the joints but do not screw the pipe together. The tips of the screws extending into the pipe would catch lint and will eventually cause a clog.

The pipe must have a slight downward pitch. (not more than 1/4" per ft.) You have to remember that the humidity of the air in that duct while the dryer is running is 100% therefore you can expect a heavy amount of condensation to form on the pipe walls. The pipe needs a slight downward pitch to permit the condensate to run out the end and not back to the dryer.

[Dan O.]

Our dryer currently vents just under the deck. I need to somehow extend the vent to the edge of the deck (about 10 feet).

Make sure the total vent length (from dryer to outdoors, accounting for all bends - see the link below) does not exceed the manufacturer's suggested maximum length for the dryer model you have. In fact, keeping it *far* short would be best.

LINK > How long can my dryer vent be?

What sort of vent pipe should I use? - 4" flexible aluminum?

Do not use that stuff inside or outside. You should go out of your way to only use rigid metal ducting.

JMO

Dan O.
www.Appliance411.com
The Appliance Information Site
=D~~~~~~

[sbennett61]

Thanks!

I really appreciate the informative (and quick!) responses to my question.

It's great to know that so many people are willing to share their knowledge and help out a total stranger. I sure appreciate it!