What type of drywall should I use? 5/8, 1/2? Moisture resistant?

[bowtie327]

Even with no building inspection, you are still required to follow the building codes.

You have options other than drywall. OSB, Plywood, Metal (steel or Aluminum), and Trusscore. I’m sure there are others, but those are whats commonly used around me.


You seem to lean towards drywall, so here are my thoughts..
For 24” OC drywall, 1/2 will sag over time so you need 5/8 to help reduce it. Notice I didn’t say its a guarantee For not sagging. BTW, 5/8 is at least 25% heavier, so a few more fasteners per sheet can’t hurt.

PCustoms has the right idea. Strap your ceiling 16” OC and use regular 1/2 drywall. Problem solved.

No matter what you install, use screws and not nails!

You can use a vapor retarding paint and omit the plastic. Less likely to trap moisture in your drywall that way.

 

[greggo]

Ceilings are 24" oc.

I'll be having blown in insulation (R38) in the attic after the drywall is hung.

It's detached and there are no permits/inspections... So, I can use whatever I'd like. Just want to make sure it won't sag on the ceiling and I don't want to worry about mold. It'll be somewhat climate controlled, but still...would prefer mold-resistant if there are no tradeoffs.

I had one guy tell me not to use mold-resistant drywall on the ceiling because it's heavier and will sag. No idea if it's true. It's also hard to find in 5/8".

Pretty much everyone told me that 1/2" would be fine for the ceiling, and mold resistant wasn't necessary, but figured I'd ask here also for some outside opinions.



5/8" all day. Its stiffer and hide imperfections in the framing. My 3100 sq.ft house is 5/8" everywhere,walls ceiling. It will also buy you a little more time in a fire, possibly saving the structure. Retired FF here.

Ret

 

[Steve_P]

I've had 1/2" drywall at 24" OC on the ceiling of the main floor of my house for 30 years. No issues. It's not sagging. It is fine. This house is in the county and was built before code enforcement.

But since this is GJ, go with two layers of 3/4 LOL.

 

[MelvinManiac]

I've had 1/2" drywall at 24" OC on the ceiling of the main floor of my house for 30 years. No issues. It's not sagging. It is fine. This house is in the county and was built before code enforcement.

But since this is GJ, go with two layers of 3/4 LOL.

lol Yes... On yours - did you have blown-in insulation on top of it?

 

[Burt Shaver]

Strap it 16” 0c

 

[ipgenie]

I don't know much about drywall (learning a few things in this thread). I do know that I don't really enjoy hanging/taping/mudding. Not relevant but I'm doing steel over ply/OSB in my shop.

I just wanted to point out that I've never visually noticed drywall sagging on a ceiling. It's not something I look for though. However, over time all drywall is likely to sag a little. One example is my in laws ceiling. No noticeable sag, but after they installed a wood stove, the residual smoke started faintly showing the truss girt lines on the ceiling. I assume it's because the smoke pools in the high spots and discolors the paint. It might show up with a straight edge, but the ceiling looks flat in spite of the smoke lines and sag.

 

[rlitman]

...One example is my in laws ceiling. No noticeable sag, but after they installed a wood stove, the residual smoke started faintly showing the truss girt lines on the ceiling. I assume it's because the smoke pools in the high spots and discolors the paint...

I would think this is more related to thermal bridging, with those lines being colder, so more likely to condense smoke. Or perhaps some weird electrostatic effect comes into play.

 

[Milton Shaw]

1/2" will sag over time, especially with the weight of insulation.

30 years ago I used 1/2" drywall and then sprayed popcorn finish on it. The water in the popcorn wet and caused the drywall to crack like crazy. Popcorn textured was just starting to go out and should have just finished and painted it, have regretted it ever since. Use 5/8 and get a drywall lift to do most of the work and make sure to stagger the joints so you don't get many geometric cracks the length of the room from thermal cracking from expansion/contraction in the ceiling trusses. Use a drywall auto feed gun and then sell it when you are through with it, Same with drywall lift buy, use, and then resell. Of course this only applies if you are do it yourself.

 

[Junkman]

Strap it, install 2 layers of 5/8" sheet rock, tape it, then install steel over the sheet rock, and you will have satisfied every suggestion that has been made in this thread. If it were me, I would strap it, 1/2" sheet rock, and call it a day. The strapping is more important for eliminating sagging, and it's not going to cost you that much.

 

[PCustoms]

Strap it, install 2 layers of 5/8" sheet rock, tape it, then install steel over the sheet rock, and you will have satisfied every suggestion that has been made in this thread. If it were me, I would strap it, 1/2" sheet rock, and call it a day. The strapping is more important for eliminating sagging, and it's not going to cost you that much.

You forgot that he needs to stagger/overlap the seams on the 2nd layer, and each layer needs to be tapped.

 

[OldCarGuy]

It's my opinion use 5/8” fire rated “X” drywall over 1/2”. Its' advantages far outweigh the minor cost difference. And a must with 24” on center trusses. Fire rated drywall is a crucial component, not only adding durability and strength. The fire protection gives peace of mind. December 2020 a laptop computer spontaneously caught fire and caused major damage to my attached 30' by 50' machine shop. The local Fire Marshall compelling statement. If this fire was at any other attached garage in the county. The fire would have burnt the shop along with the house to the ground. Taking me with it. The fire rated drywall retained the damage to the shop. Instead there was not even smoke damage to the adjacent structures nor the second floor... .



What's the chance a computer would spontaneously start a fire. Far less than 1%,, but that doesn't matter when it strikes home!

Installing isn't that difficult as many think it's a monumental task. Taping isn't rocket science and not that time consuming. Most want to apply too much mud. Making sanding overwhelming. Being in my late 70's I installed 10,000 pounds of fire rated drywall myself. The 4' by 12' sheets weight 110 pounds each. He's what it looks like on my trailer.



Using my scissors lift and a cheap drywall lift helped the installation.




The walls and ceiling are have smooth finish, Then airless spray painted using Sherwin-Williams Water-Based Catalyzed Epoxy Coating.. Making easier to clean and reflect light refection... Looking today..






.

 

[PCustoms]

Any particular reason you ran your seams like that instead of staggering them?

 

[Professor Fate]

The end butts are staggered. What you see is the screw line markings.

 

[Ultradog MN]

Ceilings are 24" oc.

I'll be having blown in insulation (R38) in the attic after the drywall is hung.

It's detached and there are no permits/inspections... So, I can use whatever I'd like. Just want to make sure it won't sag on the ceiling and I don't want to worry about mold. It'll be somewhat climate controlled, but still...would prefer mold-resistant if there are no tradeoffs.

I had one guy tell me not to use mold-resistant drywall on the ceiling because it's heavier and will sag. No idea if it's true. It's also hard to find in 5/8".

Pretty much everyone told me that 1/2" would be fine for the ceiling, and mold resistant wasn't necessary, but figured I'd ask here also for some outside opinions.

I used 5/8 type X (fire rated) through out.
It is denser and substantially heavier than the ultralight but more dent resistant, less prone to sag and I do a bit of torch work and welding in here.
I only have R15 in the walls but blew R60 of the pink stuff in the attic.

 

[sayn3ver]

If set on a taped gypsum product use something fiberglass faced like densarmor plus/gold in 5/8".

Caveats: to be truely paperless you need the joints taped in fiberglass mesh. Fibermesh requires setting compound aka hot mud for bedding so the mesh doesn't crack. Finish coats can be normal box/bucket premixed mud.

The fiberglass faced rock has a distinct grain/waffle type pattern. If it was for a house and you were looking for true smooth walls you'd have to do a tight skim coat (wipe mud on then off) to fill the weave. Not only because the weave is pretty pronounced on its own but the finished joints then stick out because they are super smooth.

Honestly, for a shop, so many other options. Using a smart membrane barrier for vapor and air control, you can use plywood or metal or anything really. One benefit of drywall is that it is a fire barrier. Having it on the walls and ceiling may by you some time in case you accidentally start one grinding or welding or with some solvent soaked rags, etc.

And like the previous poster said, type x is denser and dents less. I have type x densarmor in my bathroom because thats all the supply house near me had the day I needed it and I wanted paperless in my bathroom. Come to find out I should have went that direction for the entire house or opted for abuse resistant board (wife and kid are easy on the walls) cause the standard readily available lightweight board is junk. Screws pop more, dents by looking at it, seems to move more seasonally. the recycled paper face needs extra care for smooth finished drywall. After being on commercials sites and handling, cutting, and seeing how the 5/8" type x takes more abuse, its worth the little extra in money. Worth the extra faff in setting electrical boxes if using plastic that is, using longer screws which cost a bit more, etc. The first time I saw abuse resistant board hung on columns and in the locker rooms of a high school gym I wish I would have went with that. LOL

 

[MelvinManiac]

Thanks to all the responses here. I went with 5/8. The guys should be done hanging it tomorrow.

Full details on build in the Gallery section:

36X48 Garage Build - AKA "I Love Debt" is Underway!

Ground was broke today. Excited and nervous. Most folks in the construction world start work at sunrise. I work often at night, so probably won't be sleeping much while this is going on. Day one, they did the digging and got the footing poured. All concrete work should be done early next week...

www.garagejournal.com