Acceptable practices with installing ceiling drywall before interior walls

[atvjoel]

With engineered trusses, is it acceptable to install drywall on the ceiling before framing interior non load bearing walls? I would like to do this #1 to prevent unnecessary joints, #2 to prevent future roof sag. #3 I can get the drywall up 10x faster. I have one interior load bearing wall that separates duplex units that obviously excluded from this question.

Thanks for your help. I usually search in code book but its not really a common question. Read on a website its acceptable but they could not know what they are talking about.

Thanks

 

[atvjoel]

With engineered trusses, is it acceptable to install drywall on the ceiling before framing interior non load bearing walls? I would like to do this #1 to prevent unnecessary joints, #2 to prevent future roof sag. #3 I can get the drywall up 10x faster. I have one interior load bearing wall that separates duplex units that obviously excluded from this question.

Thanks for your help. I usually search in code book but its not really a common question. Read on a website its acceptable but they could not know what they are talking about.

Thanks

Meant to say ceiling drywall sag not roof sag.

 

[Inspector Gift]

Yes. It is not prohibited if your trusses are designed with no intermediate bearing.

 

[bill1952]

I assume you know, not so much code, but generally you want the ceiling drywall to float free of ceiling attachment around interior partitions. When it gets cold, bottom chord will rise a little and crack that wall/ceiling joint so anchor ceiling drywall to partition top plate and not near it to trusses. I dont know how you would prevent the cracks if it was continuous across partition.

 

[ICE]

How will the partition walls be secured at the top plates? What, if anything, do the plans show? The usual truss clips will not work with a layer of gypsum in the way.

 

[tmurray]

This is typical of how commercial buildings are constructed to ensure continuity of the fire separation at the ceiling.

Only issues you may find is that there may be some cracking at joints from ceiling diaphragm movement as previously mentioned.

 

[atvjoel]

I assume you know, not so much code, but generally you want the ceiling drywall to float free of ceiling attachment around interior partitions. When it gets cold, bottom chord will rise a little and crack that wall/ceiling joint so anchor ceiling drywall to partition top plate and not near it to trusses. I dont know how you would prevent the cracks if it was continuous across partition.

No I am not a code wizard. I just dont see how its going to expand and contract much. I have fox block ICFs, and plan to do rigid spray foam the entire house with superior crawl space rigid spray foam (but do plan on putting a powered vent in crawl space), only exception is I am going to flash seal the attic with rigid foam them blow in fiberglass to R60. Its a small duplex 24x64 and have 50 yards of concrete, 24" wide footing, 8" stem wall, superior compaction on excellent SW/SP soils, I find it hard to believe my home will be moving much even in cold climate, with such good insulation between the truss bottom chord and the crawl space. I suppose even the slightest moving can cause cracking so i see the argument. But seems like cracking could equally happen with 10x as many joints when you have to go around all these interior walls, if this theoretical movement is to happen. I just dont see how the interior walls are going to move much, and the bottom chord on the trusses will have superior insulation.

I guess my point is, seems as if the risk is more that the actual drywall could be more prone to cracking, but seems like the ceiling joints would be a lot less prone to cracking if its done before installing interior walls. I am sure I in the wrong here though.

This is why i am having this discussion months before I am ready for drywall, welcome to be schooled. I have never installed drywall on the ceiling before interior walls on other two houses I built, but it was 10x the work and you have 10x more joints.

 

[atvjoel]

This is typical of how commercial buildings are constructed to ensure continuity of the fire separation at the ceiling.

Only issues you may find is that there may be some cracking at joints from ceiling diaphragm movement as previously mentioned.

That would make sense on commercial. I have a duplex common wall that has an air gap and 2 seperat walls that all need 5/8 fire rated drywall. i dont think the practice is against code and dont think my inspector will say anything but I am welcome to be schooled. The trusses will bear all the weight but i do see the expansion and contraction argument. My only argument is you are inviting way more joints by not installing it first before interior walls, especially with 12' sheets of drywall.

 

[bill1952]

I believe most of your truss is above insulation and my understanding is that as the truss members get cold, they get smaller, and in particular the top and bottom chord across the grain, so bottom chord actually bows up. Over 40 years I've read quite a few articles in FHB and JLC on this, and never disputed. It's not code, just good building.

 

[atvjoel]

How will the partition walls be secured at the top plates? What, if anything, do the plans show? The usual truss clips will not work with a layer of gypsum in the way.

View attachment 8398

Plans are trash, and dont show this, just has a blurb saying refer to international building code. I could still install them

I assume you know, not so much code, but generally you want the ceiling drywall to float free of ceiling attachment around interior partitions. When it gets cold, bottom chord will rise a little and crack that wall/ceiling joint so anchor ceiling drywall to partition top plate and not near it to trusses. I dont know how you would prevent the cracks if it was continuous across partition.

Iforgot you got a bunch of live/dead load on the trusses with snow load and more weight that will be up there with sheathing and shingles., I didnt think of that. I get it know that makes sense. I will install the interior walls first and dryall after, just a lot bigger of a pain in the @$$

 

[bill1952]

better explanation https://explore.trim-tex.com/content/truss-uplift-solutions

Google "truss uplift" and please post any links that support not allowing for truss uplift.

 

[bill1952]

I will install the interior walls first and dryall after, just a lot bigger of a pain in the @$$

Exactly why I prefer rafters and ceiling joists or rafter ties. Trusses have their place, I just don't like them in small houses. Less flexible and more expensive and other issues. Plus I like the art of roof framing.

 

[atvjoel]

How will the partition walls be secured at the top plates? What, if anything, do the plans show? The usual truss clips will not work with a layer of gypsum in the way.

View attachment 8398

Its still possible to install the truss clips. I just didnt consider the added weight/dead load and live load that will be added with snow/later. I dont think its expansion and contraction, its more of settling in my eyes due to a lot of weight from shingles/snow/sheathing. I appreciate everyones comments. Seems like its no good to drywall before interior walls unless you were in arizona, even then you still got load.

 

[Beniah Naylor]

You would still have to mud the joint where the wall meets the ceiling, so installing after the walls are up isn't more work from a mud and tape point of view.

Will be a little faster to install without the walls in place, but the expansion/contraction described above will crack the mud at the junction of the wall and drywall, not necessarily the ceiling drywall itself. I think the extra time involved to install the ceiling around the walls won't be that bad, most of the cuts will be with razor and straight edge, and take very little time. I would definitely install after the walls are up - there would be nothing you could do to keep the mud from cracking out afterwards.

The trusses we get around here do not need uplift resistance at the non-load bearing walls, and they use hurricane ties or trusslock screws at the bearing walls, which would not interfere with the drywall.

I don't know what connections are required in your area to resist earth movement, Alaska is all over the map as far as seismic zones. ICE can correct me if I'm wrong, but I believe the connector he showed is a seismic consideration that he usually sees because he lives in California, which may or may not apply to you. I would research and find out what kind of seismic zone you are in, and probably contact your truss manufacturer to make sure you are using all of the hold-downs required for your area.

 

[atvjoel]

better explanation https://explore.trim-tex.com/content/truss-uplift-solutions

Google "truss uplift" and please post any links that support not allowing for truss uplift.

Ya that leads me down garden path thanks man, that brings things to my attention I would forget to think about. Almost went with rafters could have been done much cheaper. $12k later and get a boring flat ceiling. Scissor style trusses I wanted but thought they were too much of a pain in the @$$ to install with 2 man band.

 

[atvjoel]

You would still have to mud the joint where the wall meets the ceiling, so installing after the walls are up isn't more work from a mud and tape point of view.

Will be a little faster to install without the walls in place, but the expansion/contraction described above will crack the mud at the junction of the wall and drywall, not necessarily the ceiling drywall itself. I think the extra time involved to install the ceiling around the walls won't be that bad, most of the cuts will be with razor and straight edge, and take very little time. I would definitely install after the walls are up - there would be nothing you could do to keep the mud from cracking out afterwards.

The trusses we get around here do not need uplift resistance at the non-load bearing walls, and they use hurricane ties or trusslock screws at the bearing walls, which would not interfere with the drywall.

I don't know what connections are required in your area to resist earth movement, Alaska is all over the map as far as seismic zones. ICE can correct me if I'm wrong, but I believe the connector he showed is a seismic consideration that he usually sees because he lives in California, which may or may not apply to you. I would research and find out what kind of seismic zone you are in, and probably contact your truss manufacturer to make sure you are using all of the hold-downs required for your area.

Its no good to install the drywall before walls now i get into this, not going to try to be lazy. I am also in seismic zone. I do have 2x6 trusses and monster foundation but truss settling and definitely movement with seismic is huge factor. Doesnt matter how beefy you build, a 5.0 hits and you are going to be rocking.

 

[ICE]

I don't know what connections are required in your area to resist earth movement, Alaska is all over the map as far as seismic zones. ICE can correct me if I'm wrong, but I believe the connector he showed is a seismic consideration that he usually sees because he lives in California, which may or may not apply to you. I would research and find out what kind of seismic zone you are in, and probably contact your truss manufacturer to make sure you are using all of the hold-downs required for your area.

Truss clips are used to secure the top of partition walls. Truss clips allow the bottom chord of the truss to secure the wall with no bearing. How much a truss flexes is not something I know about. I would expect a fierce wind to have a slight effect as well as moisture content variations in the wood.

 

[steveray]

The truss bottom chord will bow up...Typically when the drywall stops at the non-bearing wall you put your first screw back a foot or so, so that the ceiling drywall sags and stays with the wall drywall and doesn't rip apart the tape joint....Not an issue at bearing walls...YMMVVWP

 

[Beniah Naylor]

Truss clips are used to secure the top of partition walls. Truss clips allow the bottom chord of the truss to secure the wall with no bearing. How much a truss flexes is not something I know about. I would expect a fierce wind to have a slight effect as well as moisture content variations in the wood.

Where does this practice/requirement come from? I have always seen people just shoot a couple of nails through the top plate to hold the top of the wall in place... Everyone here does that, and I had never questioned it.

 

[steveray]

Where does this practice/requirement come from? I have always seen people just shoot a couple of nails through the top plate to hold the top of the wall in place... Everyone here does that, and I had never questioned it.

Knowing how to build with trusses...Which most people don't.....

 

[mtlogcabin]

The biggest advantage code wise to sheet rocking the lid before the interior partitions are installed is in the energy code since it becomes a continuous air barrier. Any thermal imaging done on a house and the leakage is usually along the interior partition walls and the ceiling. If your trusses are only 24 ft long then your deflection should be minimal. A deflection track is what we see used around here. I have seen it used with metal or wood studs. A simple crown molding will finish off the wall to ceiling look

 

[ICE]

The biggest advantage code wise to sheet rocking the lid before the interior partitions are installed is in the energy code since it becomes a continuous air barrier. Any thermal imaging done on a house and the leakage is usually along the interior partition walls and the ceiling. If your trusses are only 24 ft long then your deflection should be minimal. A deflection track is what we see used around here. I have seen it used with metal or wood studs. A simple crown molding will finish off the wall to ceiling look

View attachment 8400

This is common with steel stud framing on commercial applications. I have not seen this used on residential applications. It would certainly perform okay. However, the bulge it creates would need to be addressed.

 

[bill1952]

The truss bottom chord will bow up...Typically when the drywall stops at the non-bearing wall you put your first screw back a foot or so, so that the ceiling drywall sags and stays with the wall drywall and doesn't rip apart the tape joint....Not an issue at bearing walls...YMMVVWP

This. A more succinct version of what I tried to say in #4. Whether or not you need the clips that laterally brace the walls to trusses while allowing it to move vertically is a different issue.

 

[atvjoel]

Where does this practice/requirement come from? I have always seen people just shoot a couple of nails through the top plate to hold the top of the wall in place... Everyone here does that, and I had never questioned it.

I remodeled one home that I planned on selling thats what i did and the inspector didnt say crap, just nailed the top plate to the bottom chord of the truss. really you could probably get away with no nails or truss clips but your wall would shake when you close the door or mount something to the wall lol, would be kind of ghetto. And honestly if you have 3 1/4 inch sinkers there is enough meat on the bone for it to move, its not like your relying on the interior wall to hold up the roof.

This house I am building has a million dollar view and i may keep it for many years, so I want to make it as solid as possible, its the only reason i am bringing this up. If i was to sell it early next year I would not be as diligent. People may shun me for saying that but they are still just interior walls. I just do not like the thought of cracking drywall, even though I think its not that big of a possibility because i am putting up my sheathing and shingles before interior walls, so it will naturally slightly settle, its just the snow load to think about. Seismic is kind of a concern but if you get a 5.0 letting your top plate float probably wont be much of a difference. i want a future buyer to be happy with their home when i go to sell.

Honestly i could probably just put up the drywall, nail the top plate into the bottom chord, no truss plates and my inspector will probably say "looks good" see you for electrical inspection.