# Poke duct sections through joists when framing



## Willin (Aug 20, 2012)

If open-web floor trusses or deep i-joists are used to frame a floor, and duct trunks are to be run in the frame, perpendicular to the trusses or joists, in other words through them, what benefit is there to having long sections of these ducts available at framing time, to shove in the openings before the joist bays are all built?

It would save having to piece and seam a lot of sixteen inch sections, no?

The framing carpenters need to slow down and stuff some metal, but they should, right?


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## ScipioAfricanus (Sep 13, 2008)

Installing ducting is not usually the carpenters responsibility, of course, but I suppose you can contract with them to install it.
I think you will find a lot of hesitation to do this on their part though. 

Andy.


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## Kent Whitten (Mar 24, 2006)

Willin said:


> If open-web floor trusses or deep i-joists are used to frame a floor, and duct trunks are to be run in the frame, perpendicular to the trusses or joists, in other words through them, what benefit is there to having long sections of these ducts available at framing time, to shove in the openings before the joist bays are all built?
> 
> It would save having to piece and seam a lot of sixteen inch sections, no?
> 
> The framing carpenters need to slow down and stuff some metal, but they should, right?



Lemme guess....you would like to drop off the ductwork and make the framers install it.


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## Willin (Aug 20, 2012)

It's been done here by both commercial and residential contractors, the jobs with trusses had chases shown on prints, the I-joist jobs were pre engineered packages with web holes CNC cut by distributor.

All it seemed to take was the kind of communication and sub and trade coordination that a good GC does.

But I never heard from any HVAC contractors with their take on this.


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## SAW.co (Jan 2, 2011)

I,m not sure I follow you correctly.
You say you are going to cut thru a series of TJ's and install duct work?
That will weaken the joist not sure the inspector will go for that.

No one in their right mind would take that responsibility for you.


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## Kent Whitten (Mar 24, 2006)

I think framers have enough to worry about without shoving HVAC work on them too. You want the ductwork installed? Get the HVAC guy out there when they are just done rolling the floor and right before they skin the outside wall. They can shove all the ductwork in they want without MAKING the framers slow down some for the convenience of long sections of ducting. 

A great planning GC also realizes when it's a burden on one particular trade, namely framers. Don't know why people tend to **** on the framers all the time.


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## Calidecks (Nov 19, 2011)

Willin said:


> If open-web floor trusses or deep i-joists are used to frame a floor, and duct trunks are to be run in the frame, perpendicular to the trusses or joists, in other words through them, what benefit is there to having long sections of these ducts available at framing time, to shove in the openings before the joist bays are all built?
> 
> It would save having to piece and seam a lot of sixteen inch sections, no?
> 
> The framing carpenters need to slow down and stuff some metal, but they should, right?


Not just no, but hell no!


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## Calidecks (Nov 19, 2011)

SAW.co said:


> I,m not sure I follow you correctly.
> You say you are going to cut thru a series of TJ's and install duct work?
> That will weaken the joist not sure the inspector will go for that.
> 
> No one in their right mind would take that responsibility for you.


I think what he's saying is the TJI s came engineered with pre stamped holes to accommodate AC ducts, believing that the framers need to stuff the ducts as they roll the joists. Hell, why not run the plumbing pipes too why were at it. And I must not forget fire sprinklers.


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## wnc viking (Aug 4, 2011)

Why on earth would you run ducts before the house is dried in ? That is like wiping before you poop


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## Kent Whitten (Mar 24, 2006)

Californiadecks said:


> Not just no, but hell no!


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## Calidecks (Nov 19, 2011)

http://m.youtube.com/#/watch?v=9o19CaOSuD8&desktop_uri=/watch?v=9o19CaOSuD8


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## Dr Heat (Dec 25, 2008)

We do it all the time just leave the sheathing off wear the duct chase is and we shove the duct in. I love running duct this way all the duct has to be custom made to fit it is a cheaper way generally to install ducts


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## thom (Nov 3, 2006)

The way DrHeat describes is the way we do it. Leave off one piece of sheathing at the mid-floor. Don't really leave it off, just have the framer tack that piece. Two nails that are left hanging will do the job. 

Making sure the ducts can be properly installed is part of the design job. Sometimes the access is through an area with a roof at single story, sometimes through a stairwell, but the most common is through the outside by leaving out a piece of sheathing.


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## Calidecks (Nov 19, 2011)

thom said:


> The way DrHeat describes is the way we do it. Leave off one piece of sheathing at the mid-floor. Don't really leave it off, just have the framer tack that piece. Two nails that are left hanging will do the job.
> 
> Making sure the ducts can be properly installed is part of the design job. Sometimes the access is through an area with a roof at single story, sometimes through a stairwell, but the most common is through the outside by leaving out a piece of sheathing.


I would definitely leave the sheathing off for anyone of the subs. One of the first thing we learned as framers/GC is to be kind to your subs, but we don't do the job for them.

Even if it is easier/faster


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## Dr Heat (Dec 25, 2008)

Do not leave the floor open I should have said leave the rim joist open.

the supply and return need to be stacked.


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