Finding Ceiling Joists

[txpackers]

I recently bought some SafeRacks storage racks to hang from my garage ceiling. My house was built in 1999 and the garage has 12' ceilings which is great to use the extra height for storage.

I started my installation and immediately ran into a problem trying to find my ceiling joists. The ceiling in my garage is drywalled and there is living space above it. I used a stud finder to find what I thought were the joists. When I drilled into it with a 3/16" bit I did hit wood, however, after about 2" my drill went right through. I thought maybe I was drilling at an angle and went through the side of the joist so I tried again nearby. Same thing. I then tried 24" over and the same thing happened. I even used a magnet and found the drywall screws, drilled next to the screw and the same thing. I checked all my holes with a wire and sure enough the hole goes right through. After Googling I finally figured out that straps were used to install my ceiling drywall. The straps run perpendicular to the joists so I have a gap between the drywall and ceiling joists. Based on my memory of the distance I was hitting wood, I'm guessing the straps used were either 5/4x3 or 2x4.

The instructions for the rack require that you install in the ceiling joists so you can use the full capacity of the rack (600 lbs)

How can I find the joists since there is a gap between the drywall and joist? A typical stud finder can't find it since the distance is too great.

Will I need to cut an access hole to find the joists?

Any suggestions would be appreciated. Thanks.

 

[CNGsaves]

Take out guts of light fixture and knock out slug so you can send boroscope snake and look around. Hopefully you'll discover the layout of ceiling joists.

If no luck at light socket, then drill exploratory hole for boroscope to look around near where you want to find joist.

Another way to increase your strength of attachment is use strips of Unistrut that you attach in MULTIPLE locations (ie every joist) rather than just the couple spots of your storage rack. Use proper grade bolts/washers in the Unistrut that will hold your storage rack.

 

[jonjon1]

Maybe the ceiling is starpped and you are drilling a fairing not a stud. Look at your rook line and figure which way the joists will run, go to the hole you drilled and move in that direction 4" if you don't hit anything you are on strapping that is attached to the joists.

2" sounds about right, figure plaster board at 5/8" {thats our local code for garages} and then another 1" for the faring, that is what I would imagine you hit, unless its a 2x laid on its side, but that would be odd.

I wish I was closer I have thermal imaging cameras that are awesome for finding studs...

 

[txpackers]

Thanks for the advice.

The rack design uses angle brackets similar to Unistrut so it can be attached to multiple joists. It requires being mounted in multiple joists.

I can try taking the light down to see what I can find. The garage only has one small light for the entire 2 car garage. That will be the next upgrade after I clear some space.

I do think it is the strapping I'm finding right now. But after further searching, I'm now wondering if I have engineered joists like shown in the first picture in the link below. If that's the case I wonder if I can just bolt into the wood I'm finding.

http://www.garagejournal.com/forum/showthread.php?t=267108&highlight=joist+finder

 

[Morrison]

Time to make a few holes.

 

[dfiler2]

Use one of these and set it to deep scan.

http://www.menards.com/main/tools-h...lite-reg-pointing-system/p-1452479-c-9167.htm

 

[OccupantRJ]

Find a spot in a hollow that you know you will be mounting a light. Cut a 4" hole to get a visual with a small mirror and flashlight. You can then measure up inside with a tape measure to locate structural members. Transfer this measure to below ceiling to find the member. Cover hole with future light installation. Wiring to the lights will have to be fished through anyway, unless you plan to surface run wiring.

 

[gregtwojeeps]

Find a spot in a hollow that you know you will be mounting a light. Cut a 4" hole to get a visual with a small mirror and flashlight. You can then measure up inside with a tape measure to locate structural members. Transfer this measure to below ceiling to find the member. Cover hole with future light installation. Wiring to the lights will have to be fished through anyway, unless you plan to surface run wiring.

+1 Use a "eared" old work 4 in. round plastic ceiling box from Lowes/HD and just install a 4 in. white round blank plate on it. It may be wired in the future for a light or just leave it unused as a conversation puzzle for future owners. " I wonder what that box is for anyway " ?

 

[dfiler2]

Find a spot in a hollow that you know you will be mounting a light. Cut a 4" hole to get a visual with a small mirror and flashlight. You can then measure up inside with a tape measure to locate structural members. Transfer this measure to below ceiling to find the member. Cover hole with future light installation. Wiring to the lights will have to be fished through anyway, unless you plan to surface run wiring.

This may work fine, however, my question is why would you strap a ceiling with rafters on 24" centers? The answer may be that the bottom cords were not consistent enough and it was easier than cutting every sheet. I would assume a home built in 1999 would have truss rafters on 24" centers.

I would still go with a good quality deep scan stud finder.

 

[Firebird 1]

My guess is you have trusses 24" oc with 1x3 strapping perpendicular at 16" oc. If youre strut is parallel with the trusses you need to put some 2x material across and anchor to the truss cord, then you will have something solid to mount your racks to. There should be some kind of access to the attic area to see what you have from above. In my neck of the woods its required by code. Even if you have to crawl across the attic of your house to get there.

 

[txpackers]

My guess is you have trusses 24" oc with 1x3 strapping perpendicular at 16" oc. If youre strut is parallel with the trusses you need to put some 2x material across and anchor to the truss cord, then you will have something solid to mount your racks to. There should be some kind of access to the attic area to see what you have from above. In my neck of the woods its required by code. Even if you have to crawl across the attic of your house to get there.

This is what I'm thinking as well. Unfortunately I don't have any access to the attic area without cutting holes. Guess that will be my project next weekend. Hopefully I can find out exactly where the strapping connects to the joists so I can connect in at the same point.

 

[txpackers]

Figured out this is what I have.

http://www.garagejournal.com/forum/attachment.php?attachmentid=382361&d=1414641357

 

[GuyllFyre]

Cut a hole, put a cover on it.
Access doors like this are handy.
I use them at work to be able to snake cables.
Most people never notice them. Not like they aren't obvious but do a neat and clean job and you won't have to worry about it.

http://www.homedepot.com/p/Everbilt-14-in-x-14-in-Wall-Access-Panel-34056/202078065?N=5yc1vZbqkz

 

[Caman]

Figured out this is what I have.

http://www.garagejournal.com/forum/attachment.php?attachmentid=382361&d=1414641357

That's exactly what my thoughts were when reading your original post.

 

[rl54921]

Bringing up an old post, but thats what forum searching will do.

I am running into the exact same issue as the OP. Used magnet and stud finder. Drilled through sheetrock, then wood as expected, but then it slid through making me second guess if I was drilling on the edge or at an angle. Stuck a coat hangar through too. Based off all the construction in my area, I bet I have the same type of ceiling joist.

Before I start cutting holes into my ceiling to verify, what was the fix? Will that sufficiently hold the rack? I am hanging one too, but not a SafeRack. Its a 4'x8'. The lag bolts it came with are 3.5" long.

 

[gmridul]

I am also having the same issue as the OP. Any advise how to install SafeRacks.

 

[firebirdparts]

floor trusses. No problem. they are not designed to have stuff hanging on the bottom, so be reasonable. They are not likely to pull apart with any sort of reasonable load, but i would imagine it would be possible to pull them apart. You can't lift a car with them.

If what you really have is I joists, then I don't think you should hang anything off those. There's just nothing there to connect to.

 

[SWFLCRX]

Use a magnetic stud finder to locate the trusses from the nails and screws. Blindly cutting or drilling holes is unprofessional in my opinion. The best thing about magnetic stud finders is they don't need batteries and will stay stuck on the ceiling or wall, while you are doing other things.

 

[chinboys]

take a bright white light and shine it on to the ceiling.
look for the sheetrock screws or nails and their dimples or any signs of a screw or nail pattern.
likewise, you can look at the walls of the room for such and use the signs of the dimples to show you where the joists are provided your builder placed the ceil joists on top of wall studs.

 

[penth2o]

I use one of those magnetic things with a long handle on it when you drop a bolt or nut in the engine compartment. I lightly run it across the ceiling till it pulls and sticks to a nail or screwhead under the tape of the drywall.
Do it a few times to find out which way your rafters are running.

 

[493mike]

Are you familiar with the old trick of using fine steel wool to locate nails/screws? Rub steel wool over the wall and small particles of steel will magnetically stick to the screws with out damaging the wall/ceiling finish. A professional drywaller showed me years ago.
Mike

 

[ripperd]

The latest posters are all giving bad advise from not reading the whole thread. Using magnets will only find the drywall screws that hold the drywall to the strapping. With a furred ceiling it will not find where the furring strips are screwed to the floor trusses. A peephole is really the easiest way.

 

[wasfast]

There are infared adapters for your phone from Flir and a lower cost one from Walabot:
https://walabot.com/diy

The Walabot is only available for Android (no iPhone). More than a stud finder, you can find pipes and thermal leaks on surfaces up to 4" thick.