DIY Chatroom Home Improvement Forum

DIY Chatroom Home Improvement Forum (
-   Building & Construction (
-   -   Garage ceiling has 2X4 joists-will it hold? (

markd 03-04-2007 04:28 PM

Garage ceiling has 2X4 joists-will it hold?
My garage was built on to the house in 1970. It is 20 x 22 feet. The walls are 9 feet high and made of 2x4's. There is a rear door and a 18 foot wide garage door. The ceiling and roof rafters run the 22 foot lenght of the garage.

The roof is of average pitch-not too steep, framed with 2x6,s. The ceiling is framed with 2x4,s that are nailed together at the center. My guess is that they took 2 14 footers and nailed them together. Each side of the "A" of the roof has a 1/2 inch thick by 8 inch wide by approximately 4 foot long piece of plywood nailed to each roof rafter and extends down to the corresponding ceiling joist where it is nailed. I live in the northeast. This structure has seen snow load, and has remained okay for 30 or so years. It has NO drywall on it. I want to drywall it and insulate it with 1/2".
Will this hold??
I think the guy that built it was a cheapskate that did not know what he was doing?
I would appreciate any advice
Can I do anything to the structure up above to strengthen it, or is it fine?


Zero Punch 03-05-2007 12:08 AM

Your fine for hanging drywall, the 2x4 ceiling joists are there to keep the walls from falling away from the weight of roof load. If your concerned double them up.

jamesdart 03-06-2007 02:49 PM

i dont think it will be fine. i see you already have some sort of hangers, but it doesnt sound like enough. not for my own garage anyway. the 2x4s are going to sag from the weight of the sheetrock. dont even think about putting storage on top of a 22' span of 2x4s either. if it is only going to hang a sheetrock cieling, i think you can run hangers from your roof framing. i would put a hanger every 4', maybe even mount them so you are trianglating and creating a truss like system, and cats every 4' between the 2x4s. what are you going to have 12 4x10 sheets? its a lot of wieght, even thought it is spread out. what are the centers on the 2x4s?

markd 03-06-2007 05:11 PM

centers are 16" on 2 x 4's

I was thinking of adding some eye hooks and aircraft cable here and there going up to the roof rafters for extra support-actually every other 2x4 to rafter 2x6 on both sides

jproffer 03-06-2007 05:41 PM

Are you sure what you have isn't trusses?

crecore 03-06-2007 07:19 PM

sounds like old school glued and nailed plywood plate trusses? the top cord will help support the bottom via vertical ties. ive designed and calculated the stresses on these, a LOT of work... but fun. post a picture and we can make a better judgement.

Brik 03-07-2007 09:07 AM

What he is describing are what I call collar ties. They are not designed to take a downward load. They keep the walls from spreading apart. Adding a few braces, like a truss, should be fine to add support for drywall. Aircraft cable would work but be expensive compared to lumber. Its a garage for petes sake, lets not go to EE school on this, just beef up the structure a bit, rock and unsulate. If it sags a little no one will notice. (It wont if you beef it up)

crecore 03-07-2007 03:54 PM

yes we know what collar ties are, couldnt tell for sure from the description.

markd 03-07-2007 09:00 PM

I will post some photos when I get a round to it.
There are 1/2 inch plywood pieces about 8 inches wide on every joist to roof rafter about 7 foot from each wall that is 24 foot long in the span of the 2x4's. then there are the same plywood pieces extended from the rafters to the joists right at the center of the 24 foot span-I believe they are holding up the 2x4's-I think it is fine, but I am going to put up a couple aircraft wire and eyebolts on every other joist just to be sure. It was built in 1975ish and has been okay since then without the weight of the new drywall ceiling.

jamesdart 03-08-2007 03:28 PM

if there are 3 braces per tie, it will probably be fine, i was thinking only one at each end.

Baron 01-06-2009 06:41 AM

I have seen this a few times before but I wouldn't hang drywall on 2x4 ceiling joist 16 OC more than 11-12 feet. More than that span I would definitely recommend additional support that doesn't increase the rafter load, especially if the rafters are already as minimal as the ceiling joists.

One way is to make a W brace from the ceiling to the rafter by dividing the ceiling span by three and the rafter span to the ridge in half and connecting those points with spruce 1x8's or 1x6s

Every other joist or third joist should stiffen the ceiling correctly then strap it for drywall. If you wanted a little storage space down the middle of the attic space install bracing on them all and install a floor down the middle area that is created.

Termite 01-06-2009 07:44 AM

Baron, you're resurrecting a post from nearly two years ago.

DanWould 01-06-2009 10:29 AM

thekctermite... it may be an old thread but co-incidentally I came looking for help with similar questions... I have a garage which is a little over 4 meters wide by nearly 7 meters deep. It has a pitch roof tiled. And ceiling joists of 2x4 at 16" spacing. I'm seriously considering adding insulation as I use this as a workshop as well as a garage. But I'm concerned the 2x4's across the 4 meter span aren't enough if I end up adding some sheet material as a ceiling + insulation + some kind of boarding to allow light storage in the loft space. (I can easily flex a joist by hand) I'd love some suggestions on what I should to to ensure that it is strong enough. I don't have much storage up there, but it would be nice to allow reasonable usage of that space. If I'm going to spend money to benefit from insulation I might as well do things properly. But what.. and how?



Baron 01-06-2009 02:46 PM

Sorry about that. I didn't actually look at the date until I had posted a more informed reply.

All times are GMT -5. The time now is 10:01 AM.

vBulletin Security provided by vBSecurity v2.2.2 (Pro) - vBulletin Mods & Addons Copyright © 2017 DragonByte Technologies Ltd.
User Alert System provided by Advanced User Tagging (Pro) - vBulletin Mods & Addons Copyright © 2017 DragonByte Technologies Ltd.

Search Engine Friendly URLs by vBSEO 3.6.1