Drywalling my ceiling

[Moonbeam]

I'm continuing work in my garage. I had a new concrete floor poured and later Floorguard coated my concrete. Prior to finding this website for research, my concrete contractor did not put a vapor barrier down, but so far so good, no problems.
I ran conduit adding more outlets and lights and now I want to finish the garage with drywall.
I think I found a problem. My ceiling joists 2X6 16" on center with a 23' span. While crawling around up there I noticed that the joists did flex a lot. A little research on joist spans revealed my joists are quite weak for that span. What do you all think is going to happen if I drywall the ceiling?
I'm sure quite a few people have garages similar to mine, not built exactly to be finished. What have you done? I was possibly thinking of hanging the drywall and then adding 2x1/4 lattice over the joints instead of trying to tape and mud them since the weak joists will probably cause them to crack.

 

[kbs2244]

Is it living space above?
A lot of walking and thus flexing of the joists?
I would think about a dropped ceiling.
It wouldn’t crack like a dry walled one and would give you access if you ever need it.

 

[GSSFC]

I would suggest adding blocking in between the joists or sister another joist if possible. Using something more ridgid such as OSB would provide a tighter ceiling but would not be as attractive.

Tim

 

[Junkman]

Where you live is a very important question before answering your question. If you are in a snow load area, then you need to fix the problem. If you don't, there is a chance that with a heavy snow load on the roof, the joists can fail. Was this building built to code and inspected?

 

[GSSFC]

The ceiling joists would not be effected by snow load. The rafters on the other hand would be, but I don't believe that is the issue.

Tim

 

[Moonbeam]

My house was built in 1971. 1st level is brick. The garage does not have a living space above it. Its a hip roof. I wouldn't say its a cheaply built house. Rafters throughout the house are 2x8 or 2x10. Just the garage is 2x6 .

Anyone else use a drop ceiling in their garage? I've never seen it. The garage is not climate controlled so would a drop ceiling be suspecitible to climate changes? I'll have to look at the stores to see what available. The idea of not having to tape and mud the ceiling is an incentive.

 

[Junkman]

The ceiling joists would not be effected by snow load. The rafters on the other hand would be, but I don't believe that is the issue.

Tim

When the roof rafters fail, the ceiling joists will pull free of the walls and the building will collapse. I have seen it happen more than once when I lived in New Hampshire and we had multiple snow storms and the roof couldn't handle the snow load.

 

[GSSFC]

When the roof rafters fail, the ceiling joists will pull free of the walls and the building will collapse. I have seen it happen more than once when I lived in New Hampshire and we had multiple snow storms and the roof couldn't handle the snow load.

Well if that happens I guess it doesn't matter how the rest of the building is built. The span for ceiling joists is not meant for a live load on them. It is mearly a medium for hanging a ceiling and containing insulation. It does provide lateral support for the walls but until the roof actually fails, it does nothing to help or hinder a snow load.

Tim

 

[Fredartic]

I don't know if it can help but... I just finish to install gypse on the ceiling and I was expected to do to the joints but it's not easy, cause it's 10 feet height so, I've got an idea; I won't do the joints, I will just hide them with a piece of MDF, around 3 or 4" wide and 1/4" thick. It will create a design on the ceiling, adding perspective and saving time and money. MDF is very not expensive.

In your case, maybe the movement won't be dramatic, cause no joints...

 

[e-tek]

First off, Am I missing something? My shop has rafters that hold the roof up and they are made of 2x4's. Not sure what you mean by joists - is that part of the rafters or in addition to? At any rate, if either roof rafters or joists below rafters were made of 2x6 on 16" centers I'd say that would be WAY strong!! I've NEVER seen anything but 2x4 rafters used on any building and I live in the snow zone in central Canada! I've had feet of snow on my shop and house and no problem. As per Fredartic, I decided to drywall, but not tape and finish and instead just caulked all the seams and screws (though I like Fred's idea of a wood/mdf cover) and painted it. It looks good and hell - it's a shop!

 

[GSSFC]

First off, Am I missing something? My shop has rafters that hold the roof up and they are made of 2x4's. Not sure what you mean by joists - is that part of the rafters or in addition to? At any rate, if either roof rafters or joists below rafters were made of 2x6 on 16" centers I'd say that would be WAY strong!! I've NEVER seen anything but 2x4 rafters used on any building and I live in the snow zone in central Canada! I've had feet of snow on my shop and house and no problem. As per Fredartic, I decided to drywall, but not tape and finish and instead just caulked all the seams and screws (though I like Fred's idea of a wood/mdf cover) and painted it. It looks good and hell - it's a shop!

You are probably referring to prefabbed trusses which are commonly 2x4 or 2x6. No way a hand framed stick built structure would be allowed to use 2x4 stock. We commonly frame with 2x10 or 2x12 dimension lumber for the roof rafters. Going so far as to you I-Joists for rafters on runs longer than 24'.

Tim

 

[Kevin54]

First off, Am I missing something? My shop has rafters that hold the roof up and they are made of 2x4's. Not sure what you mean by joists - is that part of the rafters or in addition to

You are probably referring to prefabbed trusses which are commonly 2x4 or 2x6. No way a hand framed stick built structure would be allowed to use 2x4 stock. We commonly frame with 2x10 or 2x12 dimension lumber for the roof rafters. Going so far as to you I-Joists for rafters on runs longer than 24'.

e-tek...you are thinking of a web truss as GSSFc stated. These would have the "W" 2x4's in between the top rafter and the bottom chord. What Moonbeam is speaking about in his situation is a rafter holding the roof which may be a 2x8 or it may even be a 2x6 (which it probably is, then what holds the ceiling that he want to put up is a 2x6 running from wall to wall and either nailed to the side of the rafter(which I would hope it is) or nailed to the top of the wall.

Moonbeam..to answer your question, I would sister and engineered joist that is built for that kind of span to the side of your 2x6, or take them out altogether and put in engineered joist. The reason being is that 24' is a pretty good span and even at 16" on center, when you get the weight of the drywall up there they will eventually start to bow. You may get by by putting an engineered joist at every other joist that you now have to help distribute the load. That way the cost would not be as harsh with only having to buy 9 vs 17

 

[anojones]

So the problem doesn't seem to be the 16" centers but the 23' length that's the issue. I'm not an engineer, nor any good at construction- but is there a way to block between the joists perpindicular to the 23' span to shore it up to hold a ceiling?

 

[Moonbeam]

Yes. If i jump up and grab the joist in the middle of the garage, I weigh about 180#, it will deflect about 1/2" or even a bit more if I swing around.

Sigh. Lately everything I do turns into a huge project. I thought about adding a few 2x8 joists..but where would I get a 24' board, how would I get it to my house and how would I squeeze them up there between the current 16" on center joists. Plus I have conduit running above the current 2x6's. There is also a 2x10 board running down the center of the garage laying flat on top of the joists. That seems out of the question.

There is blocking between the joists but that does nothing for the deflection I noticed.

I just want something to cover the ceiling, that looks finished, that will hide the joists, rafters and plywood roof, and reflect light better from my ceiling lights.

 

[anojones]

If you don't mind the look- how about some white vinyl backed insulation, just like the stuff they use in the walls and under the roof of pole barns. Lightweight, will give you some insulating value, is cheap and reflects light and doesn't look half bad. This site has some products- not affiliated and never used them but considered buying some at one point.
http://www.insulation4less.com/

 

[IDASHO]

Something that hasnt been brought up is installing a girder.

This is basically a header that runs perpendicular to the joists, midway between your 24' span. This would effectively change that span to two 12" spans. 2x6 is PLENTY strong to support that.

The girder would be installed below the joists, and would have to rest in 'pockets' framed into both walls.

Im considering doing this with my garage, both for increasing the live load capacity of the attic space, as well as provide a sweet location to install a trolly crane

 

[5wndwcpe]

I would say either use king studs (say 8' from either end) tied to the roof rafters, making a defacto truss and sheetrock it or do nothing and use a lightweight ceiling covering such as a beaded vinyl soffit material, thus eliminating the weight penalty and finishing troubles to boot.

 

[Kevin54]

Sigh. Lately everything I do turns into a huge project.

Hell...everthing I do, that happens to me. No matter how small the project is, it ends up costimg me probably three to four times more than what I originally estimated

Have you considered maybe a drop ceiling with the tracks that it lays in? If expense is a problem, that may be the way to go. I am considering it on the house garage myself. I will not have a lift in there and mainly it will be for aesthetic purposes but it beats putting new drywall up, taping, and finishing everything. It's a thought.

 

[kbs2244]

We are all trying to re-enforce something that doesn’t need it.
If there is no “living load” above (meaning things that move) then nothing but temp and humidity changes are going to make the ceiling move.
You could drywall it and probity never have a problem.
But I would use a dropped ceiling just because it is easier to install, lighter, gives access if ever needed, and does allow for some movement if it ever happens.
I have seen dropped ceilings used on the semi outdoor environment of drive through entrances of top line hotels in Chicago and N Y.
The panels are cheap and easy to replace if ever needed.

 

[Moonbeam]

Yes. I just went to home depot. Saw some tracks that nail right on the rafters to hold 2x4 or 2x2 ceiling tiles, so I dont lose ceiling height with traditional hanged ceilings. Thats what I'm going to do.

 

[e-tek]

You are probably referring to prefabbed trusses which are commonly 2x4 or 2x6. No way a hand framed stick built structure would be allowed to use 2x4 stock. We commonly frame with 2x10 or 2x12 dimension lumber for the roof rafters. Going so far as to you I-Joists for rafters on runs longer than 24'.

Tim

Kevin & GSSFC - THANKS!! I learn something here everynight! So, (not to hijack this thread!) but when would you use 2x6 or bigger in framing? When there's a second floor or different roof maybe? My entire structure was built with 2x4 stock, though sometimes they where doubled or more (corners, under windows). I hope they built it stong enough! Though I don' t see any drywall cracking....

 

[GSSFC]

Kevin & GSSFC - THANKS!! I learn something here everynight! So, (not to hijack this thread!) but when would you use 2x6 or bigger in framing? When there's a second floor or different roof maybe? My entire structure was built with 2x4 stock, though sometimes they where doubled or more (corners, under windows). I hope they built it stong enough! Though I don' t see any drywall cracking....

Perhaps a little terminology so we are all on the same page!

The walls or studs (the vertical pieces that make up the walls) are commonly 2x4 or 2x6 it really makes no difference, they have roughly the same strength on the long axis it is more for depth of insulation (ie bigger cavity)

The headers or horizontal members that span a door or window are size appropriate for the span the cover (ie longer span requires larger dimension lumber or multiple pieces laminated together.

The floor joists horizontal members that support the floor. Ceiling joists are horizontal members that support a ceiling or floor for the next story.

Rafters are the angled pieces that the roof decking is attached to.

Again, all of these pieces are sized according to the load they are going to carry and the unsupported distance they will span.

The original poster was asking about the horizontal pieces above his head that comprised the ceiling joists. For the unsupported span of 23' the 2x6 is inadequate. There are accepted tables that show the allowable span for various dimensions, grades and species of commonly used building materials.

Clear as mud?

Tim

 

[e-tek]

Yup!

 

[boiler7904]

Anyone else use a drop ceiling in their garage? I've never seen it. The garage is not climate controlled so would a drop ceiling be suspecitible to climate changes? I'll have to look at the stores to see what available. The idea of not having to tape and mud the ceiling is an incentive.

Drop ceilings will work if you use the right material which will probably be a special order at a big box store. You might want to look for a commercial drywall and ceiling supply house to get the right stuff. Use galvanized grid and a panel designed for wet / damp locations. You may want one of the vinyl faced gypsum board panels so that they are easy to clean.

I'd also use clips to hold the panels to the grid otherwise they'll all move up and down whenever the overhead door is up.

Biggest drawbacks are that you won't able to hang anything from the ceiling and you'll lose some ceiling height. You'll also have to get creative at the overhead door track and operator supports.

 

[Kapt]

If you have no live load above it and it will never be used for storage I think you'd be fine with drywall. With no load above it, most all of the load is in tension keeping the walls from spreading and 2x6 at 16" is more than adequate for this.

But as soon as you sell your place and the new owner discovers all this new storage space above the garage for his engine blocks, there might be a problem.

 

[351windsorsnake]

could you not place 2 ,2x8 on edge across the top of your 2x6 joists at 90 degrees with 2x2 soldiers linking them together .
Space these trimmers apart to divide the space into three even areas and have the ends land on suitable blocking on top of the walls.
This creates a very strong diaphragm as the joist and trimmers work against each other.
You can also use two 1x8 with the soldiers sandwiched between them,as the1x8 are easier to manhandle.
I have done this many times before with great results,and over here before trusses became standard we used to frame all ceilings this way.

Gary.

 

[nissan_crawler]

I'm really lost. All of mine are 2x4, but they are joined to the rafters. This is all I've ever seen. Are some roofs constructed with rafters completely free of the joists?

 

[Vicegrip]

Much to do about nothing. 1/2 deflection from 180# loaded in the center of the span is within the norm. If you have concerns about nail pops or joint cracking in drywall use drywall mastic as you install. This makes a many times better bond between the drywall and wood than DWS alone.

 

[blkhonda1991]

I'm really lost. All of mine are 2x4, but they are joined to the rafters. This is all I've ever seen. Are some roofs constructed with rafters completely free of the joists?

what you are talking about are collar ties i believe

and heres an image that shows the different framing members and their names

 

[blkhonda1991]

Heres a good resource to look at when determining framing member sizes, 2x6 maxes out at 15' according to this table
http://www.caa-online.com/library/camarillo/WoodFrameSpanTablecam700.pdf

 

[palsor1]

Like the others, not to hijack the thread, but I'll join in here with e-tek and nissan_crawler and say that my joists (the beams that are horizontal and form the ceiling of my garage) are all 2x4's and are joined to the rafters. I have a ~18 ft. span with ~22" spacing. Note that I have no living space above my garage (just attic), my house is a fairly cheap house in a subdivision built by a developer (Ryland Homes I think) so everything is pre-fabbed I'm sure.

 

[Moonbeam]

Just bought a digital camera. Picture of my 2x6 ceiling joists which started this discussion. Still working on some other things but I'm probably going to just put 1/2" drywall up there.

 

[Kevin54]

Like the others, not to hijack the thread, but I'll join in here with e-tek and nissan_crawler and say that my joists (the beams that are horizontal and form the ceiling of my garage) are all 2x4's and are joined to the rafters. I have a ~18 ft. span with ~22" spacing. Note that I have no living space above my garage (just attic), my house is a fairly cheap house in a subdivision built by a developer (Ryland Homes I think) so everything is pre-fabbed I'm sure.

Just 2x4's across is not enough to support drywall. If it is joined to the rafters like a "W" then you have a web truss. This is designed in such a way to support roof load and also support drywall. With a house in a subdivision, I think this is what you have. What Moonbeam has after lightening and looking at his pic is an older garage. The ceiling joist are not tied to the rafters with a web. The weight of drywall on this will bow over time. Just the weight of the joist slone will allow it to bow. If Moonbeam would run a taught string corner to corner you would see it. What I would do is make the ceiling joist into a truss by adding a "web". This can be done with 2x4's and plates of OSB or nail plates. Look at a common 24' web truss and take notice of placement of the web 2x's then replicate this on yours. With your joist 16" on center, you could probably do every other one for the additional support. One sheet of 1/2" drywall weighs almost 55 lbs. so you will be adding a little bit of weight overhead. A 5/8" sheet of 8' is almost 75 lbs./sht.

 

[palsor1]

Just 2x4's across is not enough to support drywall. If it is joined to the rafters like a "W" then you have a web truss. This is designed in such a way to support roof load and also support drywall. With a house in a subdivision, I think this is what you have.

I'll take a picture, but yes, this basically describes what I have.

 

[bigdav160]

It's funny how building practices are different around the country. Most homes in my area have stick built roofs. Only the cheap track houses use trusses.

You've been given good advice. I agree that those 2x6's are too small for hanging sheetrock. At that length they should probably be 2x10 or 2x12's.
As mentioned, you can install a girder. Fab up your own trusses by tying into the roof. Or sister on (with steel or engineered wood) to your current ceiling joist.

I'm suprised their not bowed a couple inches already.