Openings between floors 1

[ash060]

Working on a project that has four stories and part of the flooring area is steel grating and the balance of the area is concrete slab. The grated floor area contains vertical vessels that go pretty much the full height of the building. The client wants the grating around these vessels.

The floors are not horizontal assemblies and fire protection isn't required. When I read the code, I understand it that you can't have four story unprotected openings. And I am assuming that the grating is an opening, because it doesn't prevent travel of fire between levels.

Has anyone run into this before? Would the grating not be considered any opening?

 

[dik]

The floors are not horizontal assemblies and fire protection isn't required.

Are you sure? Doesn't seem reasonable.

Can you frame a large rectangular opening in all floors and add steel beam trim for the vertical openings and angles around the edges with checkered plate filling in where it's required?

Rather than think climate change and the corona virus as science, think of it as the wrath of God. Feel any better?

-Dik

 

[jayrod12]

We've done this on some manufacturing facilities. Are each floor a separate floor truly? Or essentially just maintenance platforms?

If the architect is saying no rating required, then I would tend to defer to them. Same for the question about unprotected openings. They're getting paid the big bucks for a reason, get the architect to answer the question.

 

[dik]

yup... jay

Rather than think climate change and the corona virus as science, think of it as the wrath of God. Feel any better?

-Dik

 

[ash060]

No architect on the project, using the special industrial exemption for the building. There are four full floors, and about 2/3rds is concrete deck and the balance has steel grating. In the grated area, there are three vessels that run vertically almost the full height of the building. The client wants to be able to "see" all the way up and down along them.

My understanding is that the special industrial exemption allows exceptions to the height and building area requirements, but nothing else (unless specifically stated in the code). So as far as I can tell, there isn't anything that says you can have open floors unless it is between two adjacent stories. I am just wondering if I am not looking in the right area of the code.

 

[HTURKAK]

Mr. ash060 (Structural);

Pls provide some clues to see the fire risk and fire protection requirements,

- Are these vessels pressure vessels or simple mixers?
- Are there fire protection around the vessel?
- Is this an open bldg? ( without facade caldding)
- What is the reason for grating ? why not checker plate or why the RC conc. slab not extended to the vessel zone?
- Can you give a clue for the industry ( petrochemical, paint, fertilizer etc?..) and the content of the vessel?

Without knowing the details, i think the use of checkered plate or the extension of RC slab for the full area and just pprovide openings at RC slab seems viable options.. A few decades ago, i designed a bldg for paint industry and there were vertical mixing vessels ..I designed the slabs with circular openings ..

 

[dik]

hturkak: The fire resistance rating of checkered plate is not great and therein lies the problem. You may be able to use an intumescent coating, but I'm not sure how they hold up in an industrial environment. You may be able to sprinkler the 'shaft' or provide additional fire protection methods. Depends on the processes and the jurisdiction.

Rather than think climate change and the corona virus as science, think of it as the wrath of God. Feel any better?

-Dik

 

[JLNJ]

IIRC we have used “atrium” provisions in the past for such industrial buildings, but it’s a stretch.

Hire an architect and work with the local AHJ.