It's A Cluster$%#@ But We Have A Handle On It

[jar546]

Owner in a high-rise condo says the contractor installed a kitchen hood and covered it up before it was inspected. GC in charge of job says they did not install a range hood. The GC's contract says otherwise. GC says the owner hired someone else to do that, but the GC admits covering up the work. There was no mechanical inspection to determine if the duct was installed properly and connected to the high-rise stack. Owner and GC are arguing over money. We created a code case, and the owner had to hire another contractor to open up the soffit and wall so we could inspect it. This is what was found.

 

[jar546]

This is an example of what some contractors do when they don't think they are getting inspected.

 

[e hilton]

That one contractor will think twice before doing that again. The other 99 contractors will mock him and keep doing what they have always done.

 

[steveray]

The other 99 contractors will mock him and keep doing what they have always done.

I got 99 contractors and good ain't one....

 

[klarenbeek]

Not only is the duct not installed properly, its not even the right duct!

He was either the low bid or someone had a guy.....

 

[jar546]

Not only is the duct not installed properly, its not even the right duct!

Yep

 

[Gregg Harris]

IBC 904.15
IFC 505.7 and 505.8
IMC 505.3
IRC 505.3
Exhaust ducts

 

[angela@hercoastaire]

Not only is the duct not installed properly, its not even the right duct!

He was either the low bid or someone had a guy.....

You nailed it! Duct Material: The duct serving the range hood should be made of rigid metal such as galvanized steel or stainless steel and should have a smooth interior surface. Metal or plastic flex ducts are prohibited. Why?

• Code & safety: Kitchen exhaust ducts must be metal; plastic flex ducts are prohibited.
• Performance: Flex duct (even metal) has ridges that restrict airflow, increase grease buildup, and shorten fan life. Manufacturers and pros recommend smooth, rigid metal duct instead.
• Exceptions: A short piece of semi-rigid aluminum duct can sometimes be used to connect the hood to rigid ducting for ease of installation, but it should be kept as short and straight as possible.

 

[klarenbeek]

Exceptions: A short piece of semi-rigid aluminum duct can sometimes be used to connect the hood to rigid ducting for ease of installation, but it should be kept as short and straight as possible.

That's not an exception in the IRC/IMC.
2021 IMC 505.3 Exhaust Ducts. Domestic cooking exhaust equipment shall discharge to the outdoors through sheet metal ducts constructed of galvanized steel, stainless steel, aluminum or copper. Such ducts shall have smooth inner walls, shall be airtight, and shall be equipped with a backdraft damper.

A tinner that has any clue what they are doing would not need to have flex to make the final connection.