Fireblocking drywall drop ceiling

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  #1  
Old 04-14-15, 07:46 PM
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Fireblocking drywall drop ceiling

I decided to do a drywall ceiling in our basement. However, I've had to drop it down with 2x4's for ductwork and plumbing. My county requires fireblocking and I understand how to do this on the walls: at the top of each stud bay and every 10ft. with vertical blocking. However, I am confused on how to fireblock the drop ceiling. The building inspector wasn't much help over the phone and I can't exactly have him come out without it being finished.
I have attached a few pictures. I've looked around on the Internet and in these forums, but I either am a slow learner or haven't found the specific answer I'm looking for. Any help is appreciated!

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Old 04-14-15, 08:03 PM
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I can't answer your question directly but I'm concerned with the 2x4s attached under the main beam. There will be considerable weight hanging on your newly installed 2x4s.

Nailed/screwed ?

The other guys should be able to answer your question on blocking.
 
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Old 04-14-15, 10:29 PM
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Pjmaxxx I would hope they're screwed but don't think weight will be a problem. Dry wall doesn't weigh that much. I'm

As for the firestops I'm not sure what fireblocking the ceiling would imply. Are youre sure they don't just mean making sure your fire stops extend to the floor above? Is the space going to be an active plenum?

Here is what a fire stop looks like From my living room to breakst room to at my hius at least
 
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Old 04-15-15, 05:01 AM
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I can't answer about the firestop but drywall does weigh a good bit, probably more than you think. Better to make sure the framing is stout and secure enough now than deal with sags a year or two later.
 
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Old 04-15-15, 05:19 AM
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My concern is the 2x4's laid on their side. They will have a tendency to bow with the weight of the sheetrock. The fireblocking referred to is where the new ceiling and the walls intersect. You will need to install a fireblock in the stud bays at that intersection.

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Old 04-15-15, 05:59 AM
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My ceiling is over 20 years old and is supported by 1x1s and I'm gussing plaster is heavier than drywall. No sagging. Here's some other pics

http://goo.gl/w2jTaM
http://goo.gl/KJOeET

To the op in the first note the wall on the left that's penetrated by the duct. That's a fire stop that's just mirrors the hallway wall where the picture was taken in the second there is what looks like an incomplete firestop. (EDIT: while looking through some other pictures I realized I was wrong, the firestop is diagonal and there is no communication between the bathroom ceiling and the bedroom.) That is between an ensuite bathroom and a small dropped ceiling in the bedroom. The duct is return from the bedroom which passes through the Bathroom into another bedroom on the other side into a plenum that is above the built in closets in the other bedroom and firestoped above the closets. This is because where we are, code requires a fire stop between bedrooms.

Obviously there's the large difference that my house isn't framed, but the principles of firestops should be the same. Youre trying to compartmentalize the flames.

Could you post the relevant section of the building code on here? If this is a county specific issue it will be hard to know exactly where the fire stops need to go without the code.
 

Last edited by Esand1; 04-15-15 at 07:18 AM.
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Old 04-15-15, 06:13 AM
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Esand1 you need to fill out your profile. We don't know where you are located, except it is not in the US. Pictures should be posted like this, since your links won't work. http://www.doityourself.com/forum/el...rt-images.html

"Supported by 1x1's" over what span? Won't work.
 
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Old 04-15-15, 06:38 AM
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I decided to just link the pictures since I didn't want to clutter up Hoosier's thread with pictures of my cieling which doesnt need help. I didn't realize the links wouldn't be clickable. As for the 1x1s you can see them in the pictures I linked the widest point is probably 7 ish feet, but as I said, 1x1.

The widest point is probably one of the bathrooms and where supported on both sides by walls the walls (I assume).

In other parts it's partially or totally suspended for example this is entirely 1 x 1 (http://goo.gl/eMcqH4)

On completely off topic issue, is there a code to make link out of web addresses on the forum?
 

Last edited by Esand1; 04-15-15 at 07:17 AM.
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Old 04-15-15, 07:12 AM
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Ok I lied, it looking through my pics it looks like the bathroom ceiling is 2x1 in the smallest bathroom. Here is a somewhat blury pick from the rewirng adventures of last month.

http://lh3.googleusercontent.com/-6h...o/IMG_8338.JPG

Here is the inside view of a drop ceiling in the kitchen supported by 1x1's and only connected to the wall on one side.

http://lh5.googleusercontent.com/-X5...o/IMG_8267.JPG

This picture called out to me for 2 reasons 1 this semi on topic, why is the hvac duct (which heads to the kitchen) covered in mortar? This is the only place in the house that this is done as far as I know. Is it to seal the space since there is natural gas present in the kitchen? Completely off topic: d oes anybody know what the purpos of the block of wood in the wire is?

Edit: figured out the linking
 
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Old 04-15-15, 07:47 AM
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My 2x4's are screwed in. To provide further support, I have installed braces coming down from the joists that are screwed into the 2x4's also. These are not immediately visible in the pictures. I would think that would be enough to support, no?

Thanks for the answer Chandler. I understand the fireblocking in the stud bays, but I believe I have to fireblock soffits, correct? At least that is what my permit refers to. Maybe I am making something out of nothing and fireblocking the stud bays and vertically every 10' on the walls is all I need to do.
 
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Old 04-15-15, 12:43 PM
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My 2x4's are screwed in
but what is the spacing between the screws? In other words, where are the screws and the length between where they are attached?
 
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Old 04-16-15, 08:57 AM
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Screws are on the ends and about every 24-36" in an approximately 70" span.
 
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Old 04-16-15, 09:50 AM
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That means the 2x4s are only secured every 2'-3' which IMO isn't enough. There would be less chance of sag if it was secured every 16"-24"
 
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