Dryer venting - code?

[miket]

I live in a town home development. Some of the owners have moved their laundry areas to the upper floor and are venting electric dryers through the roof. The plumber used single-wall pipe. I'm not sure if they were inspected, but the town is now saying code requires double-wall pipe. This is a new one on me. Is the town correct?

[bwalley]

I live in a town home development. Some of the owners have moved their laundry areas to the upper floor and are venting electric dryers through the roof. The plumber used single-wall pipe. I'm not sure if they were inspected, but the town is now saying code requires double-wall pipe. This is a new one on me. Is the town correct?

I don't know what the Code in NJ is, but in Florida Single wall pipe is legal.

I can't see why double wall pipe would be needed.

Why is the Plumber running the dryer vent? it should be the mechanical contractor doing that.

[miket]

Code is here. http://www.edgewaternj.org/btb_codes.asp

The plumber is also an HVAC contractor.

[fritzhvac]

Single wall in Kentucky, is it gas fired dryer? Yea we always run this and,
f@rt fan vent for electrians in new construction.

[bwalley]

Code is here. http://www.edgewaternj.org/btb_codes.asp

The plumber is also an HVAC contractor.

In Florida our codes are based on the International Code, I am a HVAC Contractor as well as a Plumbing Contractor and Building Contractor and I can't recall ever seeing double wall pipe on dryer vents, it has always been snap lock single wall, sometimes they will use flex but that is not a good idea IMO.

[fritzhvac]

In Florida our codes are based on the International Code, I am a HVAC Contractor as well as a Plumbing Contractor and Building Contractor and I can't recall ever seeing double wall pipe on dryer vents, it has always been snap lock single wall, sometimes they will use flex but that is not a good idea IMO.

That all I have ever seen, hard pie in walls taping joints not screwig for lint factor. Flex if out in open.Did you find code on link miket sent?

Disregard my former posts,must need some hair of the dog , electric dryers penetrating roof is probably a heat issue and rust issue . I was thinking sidewall with little flapper! SORRY...

[bwalley]

That all I have ever seen, hard pie in walls taping joints not screwig for lint factor. Flex if out in open.Did you find code on link miket sent?

Disregard my former posts,must need some hair of the dog , electric dryers penetrating roof is probably a heat issue and rust issue . I was thinking sidewall with little flapper! SORRY...

Even going through the roof in Florida all I have ever seen was single wall, it doesn't get very hot, a little warm is all.

[troyorr]

Looks like your local code department adopted the National Codes but added their own amendments. They can apply the local code, which appears to be stricter then National and International Codes, if they chose to.

[glockdoc]

Even going through the roof in Florida all I have ever seen was single wall, it doesn't get very hot, a little warm is all.

Until such time the lint build-up catches on fire. A fire starting in the dryer vent is one of the more popular ways of burning down a house. Dbl wall pipe is probably not overkill.

[DanW13]

I don't know how many of you have ever put your hand on the dryer vent when it's running, but if you have and it's not getting so hot that you are able to hold your hand on the vent, then I bet money on it that your vent it plugged up and causing your dryer to work harder than necessary and cna and will cause a fire.

I use to be on the fire department in my villiage, and dryer vents is one of the top 10 of not top 5 ways for homes to burn to the ground. My dryer vent gets so hot I can't hold my hand on the vent pipe longer than 2 minutes, and I could see why if your running this vent wither up thru the roof or out the side wall of your house that double wall pipe is used just to ensure there's no chance of any fire hazard in the section where it goes thru the wall or roof.

As I mentioned, if your vent stack isn't getting hot I would definately get it checked or looked at :couchhide:

[hvacvegas]

Maybe the code isn't for heat reasons? When I rough a house in, I prefer using bvent through my flashing than single wall pipe ;). This is all because of it being 100x easier to keep water out.

[fritzhvac]

Maybe the code isn't for heat reasons? When I rough a house in, I prefer using bvent through my flashing than single wall pipe ;). This is all because of it being 100x easier to keep water out.

Thats a very good point,even on furnaces here we are allowed 3 feet directly off furnace and there out must be double wall,that goes for water heaters too, in attics must take doublewall all the way. And Danw13 is right on, with lint hazard too, I have gotten into habit of cleaning lint trap on dryer every time I dry a load of laundry since I was a kid, one of my best friends houses burnt down from this, it only takes a second to clean!!! With or house dryer in basement we ran flex out floor joist exposed with a dryer cap (flapper) on outside of the house. I take flex down twice a year begining of summer and winter and clean it also,and take back of dryer off and vacuum the heck out of it, sounds like overkill,but its for piece of mind...

[hearthman]

NJ is based upon the IRC. According to the 2009 IRC M1502.4.1 the duct material shall have a smoothe internal surface and be constructed of a metal not less than 0.016" thick.

Per M1502.4.2, the ducts shall be supported every 4' and be oriented male end away from the appliance with no screws penetrating the duct's inner wall.

Misc.:
-limited to 25fr less derating for fittings and a tag noting the reduction or duct length within 6ft of connection. Also, if mfr. states shorter max length then listing prevails.
-allow a transition duct max 8ft listed to UL2158A and be one piece in same room as appliance. That means those plastic slinkies are illegal as are most of those crummy foil scrim slinkies from the home center

Now, if your AHJ claims they have a local ordinance over and above the IRC, then he is required to show it to you. If there is no such ordinance voted into law and he's just being a Code Nazi, you can trump him: first discuss it civilly with his boss. If no satisfaction, you can go to the State Fire Marshal. If no satisfaction, you can appeal to the ICC, who will surely vote against him. They have already demonstrated a strong dislike for code demi-gods who try to write their own freestyle codes as they go just to feed their massive egos.

Having said that, most building officials in NJ are very knowledgeable and on their game. Be nice, don't assume, but ASK questions. Ask where you can get a copy of this local ordinance because you want to be in compliance.

BTW, all contractors must be registered with the state such as HVAC, elec., etc. Home Improvement contractors must register through the Bureau of Consumer Affairs.

Technically, B-vent is not listed for this application. You would have to install it backwards meaning male end away from the appliance. Functionally, it would provide a greater level of protection in the event of a lint fire. The smoothe wall does not tend to collect lint and is usually not damaged by power brushing the way slinkies are.

FYI, the use of plastic transition ducts voids the warranties on most dryers.

HTH,
Hearthman

[DanW13]

If there's one thing all the States need to get together on is to have a unified building code for everything so there no misunderstanding on anything when it comes to items such as dryer connection, to simple items like garage door openers. As dumb as it may seem to some IMO this is definitely something that needs to be done, one book one set of codes for every state across the country so that when a person or family moves he will know the codes no matter where a person lives and the same would apply to the trades person.

[hearthman]

Dan, that is the intent of the ICC codes but not all states or jurisdictions have adopted them in whole or in part. Then again, every jurisdiction has the power to adopt local ordinances. In Pa alone, that comes to 1347 various jurisdictions.

Hearthman