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ACT ceiling - weight justification request from plan checker

T

thao.ngdo

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Jan 16, 2024
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California
Guys, seeking wisdom from the mass here.
One story strip mall reconstruction project in California. Interior ceiling spaces are mostly suspended ACT. A plan check comment came back asking "if the gypsum board ceiling is suspended, provide the manufacturer specifications for the T-bar support or provide a weight calculation that it's less than 4psf including the T-bar". Do you know where I can find specs for ACT suspended ceiling that would satisfy this? I can't go to Amstrong and ask for specs since the specs cannot be prescriptive. Providing weight calculation just seems too unnecessary cumbersome and I don't want to risk that they disagree with our calculation. Thanks in advance for your help.
 
I forgot to add, the drawing has details of ACT system which referencing ICC ESR-1308 already that dictates the 4psf weight limit.
 
Are you using a suspended gypsum ceiling? If not, call the plans examiner or BO and ask why this comment exists.
 
thao.ngdo said:
I forgot to add, the drawing has details of ACT system which referencing ICC ESR-1308 already that dictates the 4psf weight limit.
Click to expand...
This seems to answer the plan checker's question. But it contradicts what you said about not specifying a particular product. The ESR is for a specific product.

Alternatively you could simply add the note to your RCPs or the specs that require the ACT to be less than 4psf.
 
I'm on the road and don't have access to dead load tables, but I think that gypsum board is only 1 or 2 PSF. Just specify that the gypsum board shall weigh no more than 2 PSF.
 
thao.ngdo said:
Guys, seeking wisdom from the mass here.
One story strip mall reconstruction project in California. Interior ceiling spaces are mostly suspended ACT. A plan check comment came back asking "if the gypsum board ceiling is suspended, provide the manufacturer specifications for the T-bar support or provide a weight calculation that it's less than 4psf including the T-bar". Do you know where I can find specs for ACT suspended ceiling that would satisfy this? I can't go to Amstrong and ask for specs since the specs cannot be prescriptive. Providing weight calculation just seems too unnecessary cumbersome and I don't want to risk that they disagree with our calculation. Thanks in advance for your help.
Click to expand...

"ACT" -- does that mean Acoustical Ceiling Tile to you, the same as it does in the rest of the United States?

If so -- why are we discussing the weight of gypsum board?
 
Guys, the comment is regarding the whole system, gyp board and T-bar together that being suspended from the cable , to be less than 4 psf. I'm concerned whether they will accept the literature in the ICC report since this system call out to be "no more than 4psf", a small difference.
Anyhow, thanks all for your comments. Here is my approach:
-Referring to the ICC report. Thanks redeyedfly for bring it to my attention, i just realize that the report is owned by Armstrong. It seems impossible to specify any system without calling them out specifically since you have to prove that it complies.
-Also I added a note to the ACT legend specify system to be less than 4psf total.

Will update the thread of how this turns out. You guys are great !
 
thao.ngdo said:
I forgot to add, the drawing has details of ACT system which referencing ICC ESR-1308 already that dictates the 4psf weight limit.
Click to expand...

ICC ESR 1308 is for acoustic lay-in panel ceiling systems. You asked about a review comment: "A plan check comment came back asking 'if the gypsum board ceiling is suspended, provide the manufacturer specifications for the T-bar support or provide a weight calculation that it's less than 4psf including the T-bar'."

There's still a disconnect here. How did we get from an ESR for a lay-in ceiling system to asking about the weight of a gypsum board ceiling?
 
The term ACT applies to both drip in ceiling tiles and suspended gyp board ceilings per IBC section 808. The referenced ASTM standards in section 808.1.1.1 have criteria for ceilings of different weights.
 
jj1289 said:
The term ACT applies to both drip in ceiling tiles and suspended gyp board ceilings per IBC section 808. The referenced ASTM standards in section 808.1.1.1 have criteria for ceilings of different weights.
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Ummm ... No, it does not. Please explain where anything in IBC section 808 says a suspended gypsum board ceiling as ACT.

The term "ACT" has always been architects' shorthand for Acoustical Ceiling Tile.
 
IBC / CBC 808 refers to "metal suspension systems for acoustical tile and lay-in panel ceilings".
I've never seen a contractor install a T-bar ceiling grid and then cut up gyp board to lay in that grid.
Are you referring instead to a gyp board ceiling that happens to be screwed onto a metal J-track that is in turn suspended by cables from a roof or floor-ceiling structure above?

In any case, if you want to choose a proprietary system for purposes of code compliance, but the property owner does not want to be tied down to one particular system, then what you can do is:
1. Show the proprietary system and the ESR # on the plans.
2. Add this note: "Specified system shown solely to establish basis of design and code compliance, and is not intended to establish a proprietary system, nor to prohibit consideration of alternate manufactures on an equivalent basis of code compliance and performance. Any requests for substitution shall be submitted to the Architect and the Authority Having Jurisdiction for review and approval prior to purchase and/or installation. Contactor shall submit side-by-side comparison of equivalency, installed weight and reaction forces, fire, flame and smoke ratings, etc. Contractor shall pay related supplemental plan check / deferred approval fees to the AHJ as part of the substitution review process."
 
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Sometimes restaurants kitchens have lay in gypsum tiles for cleaning….but I am confused if they are talking about that or fastening drywall to a typical ACT ceiling or an Armstrong suspended drywall ceiling.
 
steveray said:
Sometimes restaurants kitchens have lay in gypsum tiles for cleaning….but I am confused if they are talking about that or fastening drywall to a typical ACT ceiling or an Armstrong suspended drywall ceiling.
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I assumed we were talking about a Chicago Grid system which looks like a standard hung T-bar ceiling grid, but sheet rock gets screwed to it and finished like a normal gyp. bd. ceiling.
 
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