does anyone know when you need 5/8″ drywall on ceiling vs 1/2″.
trying to interpret the code book is like trying to solve a mystery.
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5/8" to span framing at 24" OC
1/2" to span 16" OC
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Thanks Piffin......what about dealing with fire ratings? do you know if that's something that only comes up if you're dealing with suites? View Image View Image
"Thanks Piffin......what about dealing with fire ratings? do you know if that's something that only comes up if you're dealing with suites?"
Youre talkin commerical now where neighbors are in danger. Check the commercial code review and fergit the residential. If you dont have a book make a call to your building inspector . Ive been out a few years now so Im not calling this one and dont have the fire codes .
I dont really understand though. You will have to have a plan reveiw if you are in their jurisdiction. That gets caught in the review with the documented plans .
Fire ratings are in hours that are over residential. Memory says 1 hour which is a 1/2 and a 5/8s double wall for particians of occupancy. That was standard for commercial and fire tape up to the roof line . You have to protect the attic space as well.
I probably wrote all this for nothing .
Tim
Edited 7/17/2008 9:09 pm by Mooney
"I probably wrote all this for nothing ."I doubt it, but you did write it for free.;)
Welcome to the Taunton University of Knowledge FHB Campus at Breaktime. where ... Excellence is its own reward!
Hes probably not even got commerical or he would know .
No plan review...guy wants a quote for drywalling a room in someones house. I havn't sen it yet. But honestly couldn't remember I always use 5/8 out of habbit on the ceilings. My sub priced it for 1/2" over the phone going by info provided, simply to give the guy a cost. Would have to look at it to confirm if he really wants to do it. View Image View Image
Around here - single family, residential dwelling = 24" oc joists need 5/8" DW, 16" can use 1/2".
There are some who install 5/8" on ceilings as a matter of course, regardless of joist spacing, but it is not "code required"
There are some other multiple occupancy dwellings which require 5/8" for fire code regardless of joist spacing - not positive of details.
Jim
Edit: Piffin types way faster than me!
Edited 7/17/2008 12:28 pm ET by JTC1
"There are some other multiple occupancy dwellings which require 5/8" for fire code regardless of joist spacing - not positive of details"
that's what I've been thinking about- and can't remember the details. View Image View Image
Can only comment on local requirements for duplex units (2 homes joined together at one common wall).
At common wall moving from unit 1 through the common wall wall into unit 2: 5/8" DW, studs, 1" air gap, 2 layers of 1" Shaftliner retained by metal tracks, 1" air gap, studs, 5/8" DW - in unit 2.
Air gap at 2nd floor must be blocked solid with 1" DW; air gap at 2nd floor ceiling must also be blocked with 1" DW. Shaftliner extends to underside of roof decking and is sealed at the underside of the decking with Fire Proof mortar. Roof decking and wall sheathing must be 5/8" "fire treated" plywood for 4' on both sides of the centerline of common wall.
Depending on proximity of neighboring (unattached) structures - the exterior walls may also need to be 5/8" DW.
Probably worthless info for BC.
Call the BI and ask is the best advice I can give you.
Jim
Never underestimate the value of a sharp pencil or good light.
The Ontario Building Code (Table 9.29.5.3)allows for the following
If you have 24" centers 1/2" is allowed only with a painted finish.
A textured finish requires 5/8"
Either would have to be installed in perpendicular orientation to meet code with a textured finish.
Having said that, the general rule of thumb is 5/8" on 24" centers and 1/2" on 16's. I've seen too many wavy ceilings that are built to code.
The other factor is whether it is supporting insulation or not. 1/2" is the minimum requirement when insulation is above it (9.29.5.4)
Yeah I read some of that stuff in my code book. But was having trouble finding the fire rated info regarding ceiling. There's so much info and referring to appendixes and tables one gets lost. View Image View Image
I know what you mean. I used to pore over the code book trying to guess what they were trying to tell us. It seemed to be full of contradictions and purposeful misdirection.
The best course's I ever took were the building code courses offered here in Ontario. Now I can find the answers I need quite quickly, and can also stand my ground using code references when needed. Occasionally I get a young or inexperienced inspector or plans approver, who has never seen a stick framed roof, or can't do the math on unprotected opening allowances to the lot line.
If your work involves a lot of interaction with inspectors and permits, I recommend to everyone to take the building code courses offered locally when you have some down time. Even better, if you have a bright guy who works for you as a lead hand send him on the courses. Then he can face the plans office and inspectors leaving you to do the fun stuff.
I was talking to our BI the other day, imagine my surprise when he said we don;t even have a drywall inspection.
I always generally understood things as 5/8 24" and 1/2" at 16
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They dont but they do. Its in the code book. I realize what hes saying . He doesnt have that inspection. He doesnt do it . If they charged for every inspection the code says contractors couldnt afford it . Grey line .
You can catch it on a following inspection but is not really fair .
Commercial jobs get them becasue they pay a lot more money to the inspection department .
We were so short on money I tried to get the framing , plumbing , electrical , heating and air , all in one inspection. That inspection set up the drywall which didnt get one .
Tim
Edited 7/18/2008 11:04 am by Mooney
good advice ..I will look into what courses they have running
right now..trying to sort out some deatils on "graspable hand rails" and you're right on about conflicting info in the book. View Image View Image
Not helping you in this instance but I'll give another vote to taking some kind of course to help you navigate code book(s). I took some and don't have a problem.... Our commercial code is still a total mystery to me though....
BTW - here, code wise, 5/8 is not required anywhere in single family homes. They do have 1/2" ceiling board that can be used though. I suspect that the 5/8" on the ceiling w/ 24" OC is more important in cold climates where there is going to be more insulation (weight) in the attic.
As far as what your code requirements are, you need to talk to someone else from your providence.
Edited 7/19/2008 7:58 am ET by Matt
The course is a good idea, when I find some time, it would be worthwhile for sure View Image View Image
Always when there is another home above, in adjacent garage, or on common unit walls..this is residential. Commercial is mostly 5/8", other times multiple 1/2".
Not sure 5/8" is required if the joist spacing is 24"..unless the code has changed in the past 7 years because there is a 1/2" Ceiling Board (stiffer).
Around here only basement ceilings have to be 5/8, and that's to meet the fire code.
Garages, and over boilers or furnace.
The fire rating required depends what kind of occupancies are being separated. It varies from 45 minutes to two hours. You get that from part three of the code. Once you know the separation there are sample assemblies shown in the appendix that give you typical floor/ceilings. Apart from the fire separations, there are acoustic requirements to be met too.
Yeah I was looking at that...they got a million different variables it seems View Image View Image