Garage Shelf Ceiling Support: shelf ceiling support, wood, chain, strap, or rod?

I'm building an L shaped shelf in my garage that is about 7' off the floor and spans across a 12' bay, and extends "forwards" 6' on the "right" side. Clear floor storage.

I can tie in all sides to the studs except the "front" of the shelf. I want this to be fairly sturdy so I can put bins of car parts and heavy crap up there without it ever falling down. So, I was going to tie in the front of the shelf to the ceiling but wondered what method would GRM choose?

2x4 uprights tied into the rafters? A little clunky but plenty strong.

Chain/Cable with turnbuckles for tension?

Threaded rod bolted through bottom of shelf?

Something I haven't thought of yet?

durrr.. never mind the title repeat. repetitive title is repetitive.

I'd go for threaded rods...with threads

Rods take up the least space and are adjustable. Chain / turnbuckle is adjustable and flexible when stuff bumps into it. 2x4 is cheapest, but less hi-tech looking and takes up room. I vote chain. Cable clamps can slip.

In reply to xflowgolf:

I used threaded rod when I could easily attach a shelf to the ceiling but not to the rear wall. If I could attach to the rear wall, I'd probably just use angled brackets (metal or wood) to support the shelf from underneath (not L brackets, but a diagonal brace that attaches to the bottom at the front edge of the shelf).

Wood is your worst option.

Not because of the wood, but because of the attachment. You will be tempted to nail it, and that will be a recipe for failure when you load it. If you bolt all the attachments, it will work.

I vote the threaded rod- most idiot-proof (depending on the attachment a the top and bottom)

You didn't tell us how deep this "shelf" is, or how you are going to attach to the rafters (ceiling joists?) and shelf.

I've got a "shelf" that's more like a floor- 9' deep, spanning 20'.

If it is 2' deep, it's a different issue than if it is 6' deep.

I've seen shelves held up with a chain going through a hole and a nail underneath. Lasted for decades.

Tthis is relevant to my interests. I'm doing the same kind of thning to mount my air compressor on the wall right above my show car. Probably weighs 200 lbs, shelf will be 4 foot wide, 2.5ft deep. Cannot use diagonals underneath due to clearance.

I was thinking chains on the front running up to the floor joists above, but am watching for the answer to youur much heqvier duty question.

What is the proper application for the threaded rod option?

SVreX wrote: You didn't tell us how deep this "shelf" is, or how you are going to attach to the rafters (ceiling joists?) and shelf.

Shelf is 3' deep. 2x4 construction (perimeter frame, cross bars) with plywood on top. 3 screws at every joint. No nails.

angle with lots of holes screwed across a couple rafters. more angle or strap with lots of holes bolted to that and dropped down to/bolted to your shelf.

In reply to xflowgolf:

OK, you got us halfway there. That's a good way to build the platform. I would call a 3' deep shelf holding car parts pretty big.

Now, what are you attaching to at the top? The words "rafter", "ceiling" and "joist" seem to be being thrown around rather loosely in this thread.

Are they trusses or rafters? Are you hanging from the rafters (I doubt it- that's the framing member that the roof decking is attached directly to), or the ceiling beams? If the ceiling- how big are they and how far do they span?

I would suggest each support be distributed across at least 2 ceiling beams. Lay a 2x6 across 2 ceiling beams, and drill through the middle. Have 1 support every 4 feet or so.

Threaded rod is still my choice. I like 1/2", but 3/8" would probably work. Put a 2x4 flat under your platform, and drill through it. Drilling through the perimeter frame is no good, because you will drill out too much meat (through the 1 1/2" dimension).

Screws are not better than nails for attaching a wood support to the ceiling. They have very little shear resistance.

chain, the kind with links..

I used steel strap, like plumbing tape. I did this with lag screws with flat washers to tie into the ceiling joists, predrilled the holes so the wood wouldn't split. The other end is wrapped around the steel shelving and has a bolt/nut in it.

SVreX wrote: Now, what are you attaching to at the top? The words "rafter", "ceiling" and "joist" seem to be being thrown around rather loosely in this thread. Are they trusses or rafters? Are you hanging from the rafters (I doubt it- that's the framing member that the roof decking is attached directly to), or the ceiling beams? If the ceiling- how big are they and how far do they span? I would suggest each support be distributed across at least 2 ceiling beams. Lay a 2x6 across 2 ceiling beams, and drill through the middle. Have 1 support every 4 feet or so. Threaded rod is still my choice. I like 1/2", but 3/8" would probably work. Put a 2x4 flat under your platform, and drill through it. Drilling through the perimeter frame is no good, because you will drill out too much meat (through the 1 1/2" dimension). Screws are not better than nails for attaching a wood support to the ceiling. They have very little shear resistance.

Thanks for the detailed reply. I lack in construction terminology so that helps. I had planned on attaching to the ceiling beams in one way or another. I will have to verify the sizing, but they are trusses and they run "front to back" in this garage bay which is approximately 28' deep (the gable wall is the side wall).

I think I'm pretty well set on this idea now, I like the threaded rod, with the lumber laid across the ceiling beams to spread the load to at least 2 of them.

Thanks for the tip on not drilling through the perimeter frame as that's how I would've done it. I'll probably stack a couple 2x4's sideways within the framing of the shelf so it's not a visible addition under the bottom of the shelf frame for a cleaner look... if that makes any sense.

Off to the hardware store after work. Hopefully I can get this finished up tomorrow night. I'll post a pic or two when finished.

I don't fully understand how wood is the worse option. Understand attachment is critical with wood but if the shelf was built by the builder during construction they would use wood support and the proper size nails. Agree that bolts would be best and would do it that way myself. Or at least lag bolts. I look at it as if the shelf is made of 2X4's than 2X4's would work as supports. For some reason, I don't care much for the chain or strap method although I know they will hold. Threaded rod would work best with a piece of metal or fender washer to distribute the weight. I think the size of the washer under the nut would be the main load bearing consideration with this method, pull through being what you want to prevent. Personally I do prefer to work with metal as I understand it more than wood but wood has been used for this for longer than any of us has been around.

wlkelley3 wrote: I don't fully understand how wood is the worse option. Understand attachment is critical with wood but if the shelf was built by the builder during construction they would use wood support and the proper size nails. Agree that bolts would be best and would do it that way myself. Or at least lag bolts. I look at it as if the shelf is made of 2X4's than 2X4's would work as supports. For some reason, I don't care much for the chain or strap method although I know they will hold. Threaded rod would work best with a piece of metal or fender washer to distribute the weight. I think the size of the washer under the nut would be the main load bearing consideration with this method, pull through being what you want to prevent. Personally I do prefer to work with metal as I understand it more than wood but wood has been used for this for longer than any of us has been around.

It's not a bad option in of itself. It can be done well. It is a bad option because it will likely lead to bad decisions of attachment.

If I am understanding correctly, he is building a shelf that is approximately 54 SF and intends to load it with car parts.

It wouldn't be hard to put nearly 100 lbs per SF of load on it.

5400 lbs. Twice the weight of some of our cars. Too much to hang from a few nails.

The problem is that the wood "hangers" are in tension, and the nails (or screws) would likely be in shear. This is not a standard construction problem, and if a builder did it, he would probably make the same mistake (because builders are really good at understanding loads in compression, but suck at understanding tension).

Chain, cable, and threaded rod are all best used under tension. Wood can be used in tension (like in a truss), but it's attachments become super critical.

I didn't say wood was the worst option. I said it was his worst option, because I was getting a sense that the original poster was (just a little) limited in his construction knowledge.

Chain and cable would work, but it is easy to misuse cable clamps, kink cable, wrap chain around a truss web that puts an inappropriate stress on the truss, etc. Too many variables.

Using the threaded rod (as described) will pretty much guarantee a solid storage area, without concerns about nail size, splitting from lag screws, over-nailing, under-nailing, nailing at an inappropriate angle, fastener's resistance to shear, dried out material, etc.

Now, that's a whole lot of info nobody asked for.

I'm trying to make it easy, and safe.

In reply to SVreX:

I wasn't even the op, and had planned to ask this question later this winter when I got back to the shop renovation. your education here saved me doing this. I am greatly appreciative.

when dealing with tension forces (basement garage, 2x6 boards run side to side in the modular as the split in the house is the centerline of the shop) and attaching the 2x6 load spreader for the threaded rod, what would be the optimal way of doing this? im thinking of your number of 100lbs per square foot, on a 4x8 sheet of ply, secured at one end into a block wall with tapcons. this is a hell of a lot of tension on whatever fasteners are used in this 2x6. cant go over top of the 2x6, as that's the floor of the house. so youd have to go under. assuming the 1/2 inch threaded rod, going into a 2x6 spread across 2 joists (18 inch span) at both corners (8 foot apart), three screws per joist, that would put 300lb pullout on each screw. that's without factoring in the weight of the shelf (2x6 and 3/4 ply, braces on 18inch centers)

is my head and math right here, or am I overthinking the crap out of this? reason I ask, is that the air compressor is the first thing to go upwards. after that is 2 4x8 platforms above the garage doors for crap storage.

In reply to Dusterbd13:

Not sure I am understanding your question.

Tapcons holding a rim joist to a block wall are not primarily in tension- they are in shear. But either way, I wouldn't trust tapcons for either.

The simple answer on that seems to me to be put a couple of legs under it at the wall.

Did I underthink your problem?

Just a thought- I agree on the fact that car parts get heavy fast, but building supports to support 5400 lbs seems overkill when it's a plywood shelf that would fail far ahead of that.

Having said that, I really like the idea of threaded rods. Looks trick.

SVreX wrote: In reply to Dusterbd13: Not sure I am understanding your question. Tapcons holding a rim joist to a block wall are not primarily in tension- they are in shear. But either way, I wouldn't trust tapcons for either. The simple answer on that seems to me to be put a couple of legs under it at the wall. Did I underthink your problem?

maybe. the tapcoms would be in shear. the front edge will have to be supported to my ceiling (the floor of the house) due to space constraints. no room to make floor legs/angular under braces/etc. so the front will have to go up to my ceiling. planning on the threaded rod method. so that's the reason for my long, partially unintelligible post.

hope that helped clear it up a bit. I was tired when I typed that up last night.

Michael

Ok. Gotcha.

If you put blocks of wood between the floor joists, you will be distributing the weight to 2 floor joists. So a 2x6 on the flat (probably 14 1/2" long) would fit between 2 joists, and allow you to drill for threaded rod.

The key is to attach the block from the ends. Don't nail straight up- they will pull out when loaded. A couple if lag screws into the end will work.

I'd still put legs at the wall under the tapcons.

Make sense?

In reply to ultraclyde:

Yes, 5400 lbs is overkill. That's a lot better than the failure option.

But the issue is not the plywood. A plywood shelf can easily be built to support 100 lbs. per SF

.....questions his wood and screw shelf and canoe support system which is holding a solid 800#s of stuff over my freshly painted boat.

thanks, svrex. lag screwed into the ends between the joists, with added floor legs under the rim joist. got it.

should i double up (glued and screwed) the horizontal 2x6 top plates? little added insurance?