Does Drywall Ceiling = Structural Ceiling

[jim dungar]

The question is related to dedicated equipment space in 110.26 which uses the term structural ceiling. How can one determine if the space above the ceiling is part of the dedicated space when there is no definition of structural ceiling?

Your determine what the space is by asking the building people that make structural decisions.

But a quick internet search shows most of the architecture and ceiling sites call 'drywall and plaster' ceiling structural and suspended as having removable components.

 

[LarryFine]

I would consider the grid type that infinity mentioned to not be structural because it is suspended and by the code... suspended ceilings are not structural.

There is no question that the ceiling grid he showed is suspended, in that it hangs from above.

We still don't know how the ceiling is attached and finished, as he hasn't answered my question.

What if wood joists were hung from above with vertical wood supports, and drywalled as usual?

Can a structural ceiling be suspended? Does the suspending materiel make the only difference?

Is the ceiling material attached to roof trusses suspended? Aren't all ceilings hung from above?

 

[infinity]

There is no question that the ceiling grid he showed is suspended, in that it hangs from above.

We still don't know how the ceiling is attached and finished, as he hasn't answered my question.

It's installed like any other ceiling, wall to wall taped and painted.

 

[jim dungar]

Hmm. This website says even plaster and lath can be suspended ceilings.

Types of suspended ceiling systems

Types of suspended ceiling systems - Designing Buildings - Share your construction industry knowledge. Suspended ceilings (also referred to as dropped ceilings, drop ceilings or false ceilings) are secondary ceilings suspended from a structural floor slab above, creating a void between the...

www.designingbuildings.co.uk

 

[jaggedben]

A non structural ceiling would be able to be removed without tools in my personal definition.

Or at least, even if tools are required, it can be removed and replaced without damaging it.

 

[LarryFine]

It's installed like any other ceiling, wall to wall taped and painted.

Then, in my opinion, that would be a structural ceiling, especially in how it would affect our work.

The OP had asked about a drywall ceiling attached to trusses. Is there any doubt that's structural?

I believe a ceiling can be suspended, then rendered structural if it's finished like a drywall ceiling.

Can a structural ceiling be suspended? I don't see why not. They need not be mutually exclusive.

 

[jaggedben]

I really think that from the point of view of the relevant NEC requirement, the question is: Can you get above it to do work and then put it back the way it was without involving another trade, or not?

 

[LarryFine]

It's installed like any other ceiling, wall to wall taped and painted.

Here's a test question: May NM cable be run above it?

 

[Rock86]

Here's a test question: May NM cable be run above it?

depends... is it in a residential application? 334.12(A)(2)

 

[LarryFine]

depends... is it in a residential application? 334.12(A)(2)

To keep the discussion on topic, let's say no. Commercial environment that doesn't allow NM.

 

[don_resqcapt19]

Hmm. This website says even plaster and lath can be suspended ceilings.

Types of suspended ceiling systems

Types of suspended ceiling systems - Designing Buildings - Share your construction industry knowledge. Suspended ceilings (also referred to as dropped ceilings, drop ceilings or false ceilings) are secondary ceilings suspended from a structural floor slab above, creating a void between the...

www.designingbuildings.co.uk

I remember walking on the old metal lath and plaster suspended ceilings. Typically 1.5" black iron hung using heavy wire with 3/4" iron in between the black iron, and the metal lath tie wired to the 3/4" iron. The whole assembly suspended from the actual structure with #9 wire.

I think the code should replace "suspended" with "lay-in" as this is a common question.

 

[letgomywago]

Or at least, even if tools are required, it can be removed and replaced without damaging it.

I disagree here's why
Is a shop with screwed fire rated plywood a structural ceiling?
I'd call that a structural ceiling but there wouldn't necessarily be anything other than 20 screws holding it up.