Should dryer exhaust duct attach to dryer roof vent?

[pb4uski]

I'm hoping this knowlegable group might be able to help me.

Our condos are getting roofs replaced soon and we are about to go out for proposals. The condos were built in the late 70s. The clothes dryer exhaust duct ends about an inch from the dryer roof vent... there is no physical connection... the end of the duct just points towards the roof vent opening.

I find this odd. In my experience the clothes dryer exhaust duct is attached to the vent, but the vents that I am more familiar with are sidewall vents and not rooftop vents.

I can't find anything that requires it to be attached, but perhaps it is so elementary that they don't feel a need to specify that it needs to be attached.

Thoughts? Is this perhaps a Florida thing?

 

[RobbieB]

Me too. When the dryer is running does a lot of hot air leak out the gap?

 

[pb4uski]

Me too. When the dryer is running does a lot of hot air leak out the gap?

Not sure, I was only up there once and the dryer wasn running when I was up there.

 

[HawkeyeNFO]

So the duct ends inside the wall? Or inside the attic? Either one of those could be a fire hazard.

It could also lead to mold. If you're putting hot humid air into your attic due to a leaky dryer duct, then the water vapor has no place to go. It will condense on cooler surfaces in the attic, and voila, mold will start to grow.

 

[l8_apex]

They absolutely should connect. Just something that happened due to poor construction or during dryer installation (i.e. somebody pulled the hose off the cap while installing the dryer)

 

[JRon]

I don’t know about Florida specifically, but those 2 should be connected.

 

[pb4uski]

So the duct ends inside the wall? Or inside the attic? Either one of those could be a fire hazard.

It could also lead to mold. If you're putting hot humid air into your attic due to a leaky dryer duct, then the water vapor has no place to go. It will condense on cooler surfaces in the attic, and voila, mold will start to grow.

No, the duct doesn't end in a wall or inside the attic... those would be clear no-nos.

Perhaps I wasn't clear... the dryer exhaust duct ends a tad below the bottom of the roof sheathing... and the roof vent (aka ventilation jack or gooseneck vent) is on top of the roof sheathing so there is a ~1" gap between the end of the dryer exhaust duct and the roof vent.

Wish that I had a picture but I don't.

 

[pb4uski]

They absolutely should connect. Just something that happened due to poor construction or during dryer installation (i.e. somebody pulled the hose off the cap while installing the dryer)

It had to be during construction because all the dryer exhaust ducts in the buildings are like I described.

 

[PaunchyPirate]

No, perhaps I wasn't clear... the dryer exhaust duct ends a tad below the bottom of the roof sheathing... and the roof vent (aka ventilation jack or gooseneck vent) is on top of the roof sheathing so there is a ~1" gap between the end of the dryer exhaust duct and the roof vent.

Wish that I had a picture but I don't.

This is not normal and should be fixed.

 

[Sunset]

Sounds like a joiner pipe between the roof vent and the dryer exhaust duct is missing.

I think (don't know code) that the 2 should be connected, it was just some lazy installer that didn't connect them.

Without a connection, the air is going to basically blow everywhere, some will go out, but some will due to back pressure go to the sides, the sheathing is going to get a lot of moisture exposure.

 

[Telly]

I wonder if in the last building re-roof they weren't connected back up. Like maybe new vent housings that didn't have as long as a tail. Or there was a connector like Sunset mentions, and they just yanked off whatever came out with the old vent housing.

 

[finnski1]

No that's not normal. They should be connected and securely at that!

 

[Telly]

It had to be during construction because all the dryer exhaust ducts in the buildings are like I described.

How did you determine that? Could you see other unit's dryer vent stacks from your attic? If so... no firewall between units?

 

[Breedlove]

My dryer doesn’t require a vent

 

[Telly]

My dryer doesn’t require a vent

Does your dryer stop working on rainy days, but automatically resets when the rain is over?

 

[Breedlove]

Na my dryer is a washer dryer unit in one unit . Dries by spinning . Runs on 110 and no vent . Doesn’t overheat the house .

 

[qwerty3656]

I just had to fix ours. It is attached to a roof vent.

 

[pb4uski]

It had to be during construction because all the dryer exhaust ducts in the buildings are like I described.

How did you determine that? Could you see other unit's dryer vent stacks from your attic? If so... no firewall between units?

It talked with the maintenance guy who is frequently in the attics for other reasons and he told me that they were all done that way (not connected that is).

 

[omni550]

pb4uski,

The dryer vents ideally need to be connected to an outside vent.

In my condo complex, when we hired a company to come in and clean out everyone's dryer vent lines, we found a unit that somehow did not have an outside vent...and the Board was quick to get a maintenance worker to add the vent and connect the dryer hose to it.

If the hose stops short somewhere in the under-roof area, it's blowing hot, moist air up there along with the lint that makes it past the lint collector in the dryer. None of this is particularly good for that under-roof area.

omni

PS: In northern climates, I've heard tales of some people having the dryer vent exhausting into the house, just to add some humidity to the air in the dry winters. This is not common.

 

[wolf]

Simple. As other have noted. Dryer exhaust = Warm moist air + lint.
Must be vented outside of the building. If vented inside. Risk mold/dry rot. Lint build up potential fire hazard.

 

[Jerry1]

I had my bathroom vent like that for years until I got around to fixing it. When the house was built, they just took a flex pipe up to a roof vent and nailed it to the sheathing. I’m guessing that’s what was done with your dryer vents. My bathroom vent never caused any problem, but I think a dryer vent would be worse. Eventually, I ducted mine properly to an outside wall with a direct connection.

Now, my current house has the dryer vent through the roof and yes, it’s a fully connected vent. The one below is the vent I got.

https://dryerjack.com/djk486.html

ETA:
Duh, I just relooked at your picture and it’s a dryer jack. That’s a great vent, I can’t imagine why they didn’t hook it up properly except for laziness or just down right unprofessional.

 

[GalaxyBoy]

Installation must be in accordance with the manufacturer’s instructions. You probably don’t have that available but dryerjack has a lot of info on their web site, including code requirements: https://dryerjack.com/dryer-termination-code.html

I’m sure they should be connected. Be careful to observe the code requirements not to use sheet metal screws or similar as they present an obstruction in the duct giving a place for lint to be caught. Screens are a no no as well.

SF Gate has a web page on this as well: https://homeguides.sfgate.com/install-rooftop-dryer-vents-21258.html

 

[qwerty3656]

Screens are a no no as well.

Don't you run the risk of a rodent getting in? As I said in an early post, I just re-connected mine to the Attic vent and there was definitely a fine mesh screen.

 

[Jerry1]

Don't you run the risk of a rodent getting in? As I said in an early post, I just re-connected mine to the Attic vent and there was definitely a fine mesh screen.

No. There should be a door/flap that shuts when there is no air from the dryer coming out. That should keep any pests out.

 

[Chuckanut]

Same with my place. The dryer duct and the bathroom vent fans end about 1-2 inches from the vent on the roof. My roof will probably be replaced next year and at that time the HOA is planning to securely connect any such vents to the duct. So far no attic issues seem to have shown up (mold, dry rot, etc.). Maybe we are just lucky.