Pipes through elevator machine room

[Ana]

I have an existing five story commercial building in VA. The building has a 2hr rated elevator shaft with a machine room abutting it that is enclosed with a 2 hr rated enclosure. So far so good. During a renovation project for the elevator the Contractor found existing pipes and ducts passing through the existing machine room and serving other areas of the building, I checked the existing building drawings and I see that they enclosed ducts passing through similar spaces with 2 layers of 5/8” dry wall on 2 1/2” metal studs enclosure. I looked everywhere for this assembly and can’t find anything like that for horizontal assemblies, all I could find is the typical detail for the 2 hr rated horizontal enclosure (ceiling) that includes 2 layers of 5/8” drywall on 4” C H stud and then 1” shaft liner on top. So my two questions: where did the assembly that the base building drawings are showing come from? Was it used in the 80’s when the drawings were made? And the second question, what would you do to enclose such pipes and ducts passing through the elevator machine room, would you enclose them separately or just provide a 2 hr rated ceiling that has the shaft liner at the top? Can I just provide 2 layers of 5/8” drywall type x on 4” studs for the ceiling without the extra 1” shaft liner? Thanks

 

[Gregg Harris]

IBC chapter 30

 

[Ana]

IBC chapter 30

Thank you. Yes, everything complies with the sections in IBC chapter 30. My question is not about where to find the requirements though.

 

[walker.t]

I have an existing five story commercial building in VA.

If it’s an existing condition, why do you need to do anything with the pipes and ducts? I would have assumed that they were compliant with the code that was in effect when the building was built and could remain as they are until they are modified.

where did the assembly that the base building drawings are showing come from? Was it used in the 80’s when the drawings were made?

The way I see things done now the architect will call out a tested assembly number from UL or the Gypsum Association (or whatever,) if the original drawings don’t have that information there’s no way to know where they got their assembly.

And the second question, what would you do to enclose such pipes and ducts passing through the elevator machine room, would you enclose them separately or just provide a 2 hr rated ceiling that has the shaft liner at the top?

Hard to say without knowing more about the space, are they tight to the ceiling, how many are there, are they bunched together, how far are they below the ceiling, et cetera. If they’re all over the place it would probably be easier to install a new ceiling, but to go back to my first comment, not sure why you need to do anything if this is an existing condition.

Can I just provide 2 layers of 5/8” drywall type x on 4” studs for the ceiling without the extra 1” shaft liner?

I would only use a tested assembly, that will give you fastener requirements and list any proprietary products you need to use for that given detail.

 

[Ana]

If it’s an existing condition, why do you need to do anything with the pipes and ducts? I would have assumed that they were compliant with the code that was in effect when the building was built and could remain as they are until they are modified.


The way I see things done now the architect will call out a tested assembly number from UL or the Gypsum Association (or whatever,) if the original drawings don’t have that information there’s no way to know where they got their assembly.


Hard to say without knowing more about the space, are they tight to the ceiling, how many are there, are they bunched together, how far are they below the ceiling, et cetera. If they’re all over the place it would probably be easier to install a new ceiling, but to go back to my first comment, not sure why you need to do anything if this is an existing condition.


I would only use a tested assembly, that will give you fastener requirements and list any proprietary products you need to use for that given detail.

Thank you. Some of those pipes/ducts are being modified during the renovation project that’s why the fire rated enclosure discussion came up. I think you’re right, I’ll stick with the full ul tested horizontal assembly ceiling since there’s a whole bunch of those pipes/ducts and not enough space to enclose them separately.

 

[walker.t]

Thank you. Some of those pipes/ducts are being modified during the renovation project that’s why the fire rated enclosure discussion came up.

You’re welcome. I understand now your concern regarding how some of the existing elements are being modified.

I’ll stick with the full ul tested horizontal assembly ceiling since there’s a whole bunch of those pipes/ducts and not enough space to enclose them separately.

Here’s a link to a USG catalogue, it lists the UL test for each detail, you can then research the UL detail to see what other manufacturer’s products can be used.

https://www.usg.com/content/dam/USG_Marketing_Communications/united_states/product_promotional_materials/finished_assets/usg-fire-resistant-assemblies-catalog-en-SA100.pdf

 

[Ana]

You’re welcome. I understand now your concern regarding how some of the existing elements are being modified.


Here’s a link to a USG catalogue, it lists the UL test for each detail, you can then research the UL detail to see what other manufacturer’s products can be used.

https://www.usg.com/content/dam/USG_Marketing_Communications/united_states/product_promotional_materials/finished_assets/usg-fire-resistant-assemblies-catalog-en-SA100.pdf

Thanks again!

 

[Paul Sweet]

Gypsum Association GA600 Fire Resistance Manual is a good source for generic assemblies. The 2009 edition was the last free one.

If you use a proprietary assembly, you can only use the brands and products listed. A generic assembly allows you to use Type X gypsum board by any manufacturer.