Sheetrock Walls

[mstrlucky74]

Guess in an commerical office space with hung ceilings when does the sheetrock stop at the hung ceiling and when does it go all the way up to the slab/or deck? Asking because I guess the only time you would need to firestop your work( if fire rated wall) is if the sheetrock went up past the hung ceiling. Otherwise your conduits/cables would just be supported above the ceilings going from room to room and not penetrate any walls. See attached.

 

[jumper]

Correct.

 

[ActionDave]

Hardest job I ever did was drilling a hole in a wall that wasn't there.

 

[mstrlucky74]

Hardest job I ever did was drilling a hole in a wall that wasn't there.

lol.. but you may have to set a sleeve if wall is going up. but i'd imagine just bustin hle through rock is the way to go.

 

[MAC702]

Some walls slow down fires. Others just hold up paint.

 

[jumper]

Hardest job I ever did was drilling a hole in a wall that wasn't there.

 

[Strathead]

In my experience this is totally a specification, customer issue. Other posters maybe didn't notice that the walls that penetrate the grid don't go all the way to the deck. For example, the University I work at requires all walls to penetrate the grid, but a high rise I worked in only required 1 hour demising walls to penetrate.

 

[cowboyjwc]

They may go all the way up for sound too. All the way to the floor or roof doesn't necessarily mean rated, but it is a good indicator.

 

[Strathead]

They may go all the way up for sound too. All the way to the floor or roof doesn't necessarily mean rated, but it is a good indicator.

I was doing shorthand.

 

[mstrlucky74]

Thanks. So point is hen estimating you should know this so you can properly account for firestopping.

 

[cowboyjwc]

Thanks. So point is hen estimating you should know this so you can properly account for firestopping.

That would be correct. Went to a job one day and just shook my head when I walked in, wired glass on the outside and two layers of drywall on the inside and the guys had just tore this wall up. I gave them a stop work notice and told them to have the architect tell them how to repair it to get the rating back. So yes, do your homework, it could be a costly mistake.

 

[Strathead]

Thanks. So point is hen estimating you should know this so you can properly account for firestopping.

Sort of. But this would be backwards. As an estimator you should be aware of what walls are rated, but generally you would do this by finding them designated on the Architectural sheets

 

[mstrlucky74]

Sort of. But this would be backwards. As an estimator you should be aware of what walls are rated, but generally you would do this by finding them designated on the Architectural sheets

Yeas and I alwys look over archs, structural, mech etc. Yes the arch drawings will show all the info for the walls. Just because it's a rated wall doesn't mean it goes past the hung ceiling?

 

[jumper]

Yeas and I alwys look over archs, structural, mech etc. Yes the arch drawings will show all the info for the walls. Just because it's a rated wall doesn't mean it goes past the hung ceiling?

I am pretty sure all rated walls go past the suspended ceiling up to the hard deck above.

I cannot see how they could not, but I am no expert by any means.

 

[jumper]

I am pretty sure all rated walls go past the suspended ceiling up to the hard deck above.

I cannot see how they could not, but I am no expert by any means.

Quickly reading through this thread from a building code forum:

https://www.thebuildingcodeforum.co...-suspended-ceiling-for-fire-separation.11757/

I am thinking that I may be correct. Sheetrock has to be floor to structural ceiling.

 

[mstrlucky74]

I am pretty sure all rated walls go past the suspended ceiling up to the hard deck above.

I cannot see how they could not, but I am no expert by any means.

For sure that makes sense.

Sent from my SM-N960U using Tapatalk

 

[GoldDigger]

Quickly reading through this thread from a building code forum:

https://www.thebuildingcodeforum.co...-suspended-ceiling-for-fire-separation.11757/

I am thinking that I may be correct. Sheetrock has to be floor to structural ceiling.

I think that it may still depend on what the wall is separating. If there is a "room" which contains a fire hazard that requires a rated wall, that room could be topped by a "rated ceiling" and maintain the required protection. But as a practical matter, rather than build such a rated ceiling, it is easier to let the existing structural ceiling serve that purpose.

 

[Strathead]

Yeas and I alwys look over archs, structural, mech etc. Yes the arch drawings will show all the info for the walls. Just because it's a rated wall doesn't mean it goes past the hung ceiling?

No, just because it goes past the hung ceiling doesn't mean it is rated. It will always go past an acoustical ceiling if it is rated.

 

[cowboyjwc]

No, just because it goes past the hung ceiling doesn't mean it is rated. It will always go past an acoustical ceiling if it is rated.

That's correct, many time's in a corridor you'll have a suspended ceiling, but just above that you'll have a hard lid, because the created a tunnel.