# Wood framing/furring for suspended drywall ceiling



## akm

Looking for good ideas/details to construct a wood framed/furred suspended drywall ceiling.
An example is attached... not necessarily what am looking for, but it may at least help clarify the question ?
Any tried and true ideas would be great.


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## EmmCeeDee

How much of a drop from framing to drywall?


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## KennMacMoragh

Any reason you want it suspended and not secured to the walls? The members look over spanned in that drawing, where did it come from?


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## A-1 Interiors

does it have to be wood ? you could use a chicago grid ceiling (650 grid ) installs like acoustical then you hang board on it( for commercial fire rated ceilings) 
http://products.construction.com/swts_content_files/2215/239137.pdf


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## moorewarner

Yeah, whats the purpose for the drop, leveling, mechanicals, cover old plaster?


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## Seven-Delta-FortyOne

Is this commercial or residential?

I did one once where I bolted ledgers to the studs with Ledgerloks, and hung joists between the ledgers from joist hangers. Span wasn't too great, though.


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## akm

*Followup*

Thank you for the replies and good questions !
Answers (hopefully) to questions...

1. residential addition, space (mechanicals) for duct runs etc (soffits not an option)

2. 20' x 20' rec room with extra height available, bedrooms/bathroom above (so also need to reduce noise to above rooms)

3. 'wood' idea to keep it in local carpenter realm

4. probably would be secured at walls (maybe hang with wood members?), dwg from Knauf Drywall brochure kinda different, but maybe creates some thoughts ?

May have missed something, so please let know.


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## Seven-Delta-FortyOne

2x8 Doug Fir spans 23'10" as a cieling joist, drywall attached, no attic storage, which sounds like it would apply to your situation, as it's basically a drop cieling.

Ledgerlok ledger boards to the walls where you want the cieling to come down to, and mount joist hangers. :thumbsup:

2x6 DF spans 19'11" at 12" centers. Minus 3" for for the 2 ledgers, and you're in there. :thumbsup:


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## akm

Thanks for the suggestion.

Sorry, should have been more accurate, I generalized too much... checked the plans, the spans are actually 25'x24.5'.

But, with that said, finding 'straight' 2xs that long may be tough.

Did think about 2x4s on edge with flush 'rims' at maybe 6'-8'oc, hung by wires at 4'oc... not calcd, just for discussion purposes.

Or, maybe open web trusses for the entire floor framing... more cost effective in terms of labor etc ?


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## Seven-Delta-FortyOne

akm said:


> Thanks for the suggestion.
> But, with that said, finding 'straight' 2xs that long may be tough.


 I wonder if you could install some kind of hanger, like Simpson strapping, to stabilize mid-span a bit. It's not _really_ structural, but you could always run it by your engineer anyway. 




> Or, maybe open web trusses for the entire floor framing... more cost effective in terms of labor etc


Labor to install open web floor trusses is not gonna be cheaper than framing with demension lumber I don't think.


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## EmmCeeDee

If you want dead flat you could hang steel channel perpendicular to the existing floor joists, then clip hat channel to that @ 16" o.c.


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## akm

The more me thinks about it, the trusses may be the way to go... 24' floor and clg span, with mech space, all in one... maybe a little more 'prescriptive', and seems like it should be less labor, plus lumber is not cheap these days.
Sound proofing may be a bit more predictable, and the engineering can be left up to the truss mfr 
Guess it could be bid out as a framing contr option ?


A.T.C. said:


> Labor to install open web floor trusses is not gonna be cheaper than framing with dimension lumber I don't think.


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## alboston

Frame it with steel studs.


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## moorewarner

Yeah, I am asking why not steel as well.


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## slowsol

Another vote or a dropped metal grid.


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## BlueRidgeGreen

Steel. S-T-E-E-L......steel.


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## Tom M

I've installed dropped steel ceilng grid from USG. Explore the steel options like everyone suggested.


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## Tom M

If you know your duct layout,you can draw it on the ground and plan supports. Use chaulk lines,hair spray and a laser to draw and transfer.


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## akm

Looks like you steel-guys are all from back east (of the Mississippi) 
But, maybe we can find some west-coast residential drywall guys who know what they are doing (with suspended metal channels with drywall clgs) and some (high) STC info to back it up... btw, any STC (online or other available docs) info to go along with your steel suggestion/s ?



Tom M said:


> I've installed dropped steel ceilng grid from USG. Explore the steel options like everyone suggested.


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## Tom M

http://www.usg.com/rc/system-catalogs/usg-drywall-suspension-system-catalog-en-AC3152.pdf


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## akm

Thanks for the reference, lots of good details.
Although, couldnt find anything about STC (Sound Transmission Class) ratings for the suspended drywall clgs below a wood floor... unless missed something ?



Tom M said:


> http://www.usg.com/rc/system-catalogs/usg-drywall-suspension-system-catalog-en-AC3152.pdf


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## GCTony

akm said:


> Thanks for the reference, lots of good details.
> Although, couldnt find anything about STC (Sound Transmission Class) ratings for the suspended drywall clgs below a wood floor... unless missed something ?


The suspended system doesn't have a stc rating on it's own, the only rating you pick up will be in the individual components. (drywall, sound batts)


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## bwiab

Reduce sound transmission

1. Fill the void with batt insulation to reduce sound transfer. 
2. Could also put resilient channels on the bottom of the steel framing. 
3.Add layer of drywall then rc then ceiling.
4. Add high quality pad beneath floating floor above. 
5. Caulk all voids and penetrations
6. How much do you want to spend?


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## akm

Thanks for the replies.
Couple comments...

Wood framing (not metal), but yes, looks like improvisation may be the only way to go... like maybe modifying the some of the details in the attached pdf per your notes, use resilient metal channels instead of Ts, etc.
The client is still working on the budget estimate priorities, but money is an object.



bwiab said:


> Reduce sound transmission
> 1. Fill the void with batt insulation to reduce sound transfer.
> 2. Could also put resilient channels on the bottom of the steel framing.
> 3.Add layer of drywall then rc then ceiling.
> 4. Add high quality pad beneath floating floor above.
> 5. Caulk all voids and penetrations
> 6. How much do you want to spend?


Did find an STC reference in the 'archives' (attached pdf).
Kinda old, but gives some idea.
Havent found any updates... but may have some other possibilities coming up.



GCTony said:


> The suspended system doesn't have a stc rating on it's own, the only rating you pick up will be in the individual components. (drywall, sound batts)


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## bwiab

If you use RC, when installing the drywall, be careful not to plow through the rc with your fastener into the joists. That basically renders the rc useless.


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## CarpenterSFO

alboston said:


> Frame it with steel studs.


+1 on steel studs - cheap, easy, reliable.

Don't forget firestop questions introduced by the dropped ceiling.


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## akm

Good points !
Thanks for the heads-up.



CarpenterSFO said:


> +1 on steel studs - cheap, easy, reliable.
> Don't forget firestop questions introduced by the dropped ceiling.





bwiab said:


> If you use RC, when installing the drywall, be careful not to plow through the rc with your fastener into the joists. That basically renders the rc useless.


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## akm

Ps: 
At least dont need to worry about the 'draftstop' question 



CarpenterSFO said:


> Don't forget firestop questions introduced by the dropped ceiling.


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## Tom M

Draft stop only comes in with 1000 sf I think.


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## Deckhead

Why not run a beam down the center where span is shorter bucketed or pocketed, throw 2x6 rafters in that would only span about 12'@16" o.c. and boom, done.

Personally I would use 21guage steel 1/4" all thread and hanging clamps throw some wire up in between in place to help rigidity, I've hung some massive restaurant hanging walls with that.


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## ubcguy89

chicago grid
1 ceiling will be nice an level
2 faster than wood framing
3 installs like regular accoustical grid, and you accuracy is not that critical, so therefore you can get anyone to do it (with that said, you should still square your grid up) I install alot of suprafine and accuracy is very critical


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