How strong are lag bolts in wood: my winter wheel storage project

[SpeedracerIndy]

I got tired of the winter wheels for my Audi taking up space in the garage, so I decided to create a rack to store them in the garage out of the way. I went to Lowes, and "designed" a rack using angle iron. I used 3 1/2" lag bolts to bolt the whole rack into the 2x6 studs at the top of the garaged ceiling. My questions is, does anyone know how much weight 3, 3 1/2" x 3/8" lag bolts can reliably hold in wood? The reason I am wondering is in the last picture below. As I was putting the tires in the rack, they were a lot heavier than I remembered. When I put the 911 away for the night, I had horrible images of the lag bolts pulling out of the studs and dumping 4 tires on the hood and roof. Any bolt experts around that can put my mind at ease?

Sorry for the cruddy cell phone pics:

[gassy]

They aren't gonna go anywhere.

[ben parrish]

The lags will hold fine. It would take a lot more weight to shear the lags off. You could add some vertical supports at the end of each triangle going up to the rafters if you are really worried.

[SpeedracerIndy]

Originally Posted by ben parrish

The lags will hold fine. It would take a lot more weight to shear the lags off. You could add some vertical supports at the end of each triangle going up to the rafters if you are really worried.

Thanks for easing my mind guys! I tend to over engineer these things, but having the 911 parked under there got me a little worried.

I will probably add a few supports to the rafters as a safety precaution.

[rick-l]

From the pictures it looks like the 3/8" lag bolts go into the edge of the 2x6 plate ( 1 1/2 inches wide). How did you do that without splitting it?

[porsche4life]

Can you drill those blocks? A concrete anchor or a really big Walldog would take a lot of load off the wood

[stomachmonkey]

I woulda used Mighty Putty.

[Zeke]

I can't see how you ran the bolts. At right angle to the load, you should be fine. If you like, you could add a cable thru the centers of the wheels for safety. Your cross support looks t be maxed.

[Amail]

I know you didn't ask for other critiques, but here's mine never-the-less.

Run the diagonal leg to the same hole that the cross pipe is and use one fastener to capture them all. That way the horizontal leg is not put in bending.

Also, shorten the horizontal leg to just past the cross pipe. Extra material hanging out there doesn't help, but you sure may scalp yourself on it one day.

[javadog]

^^ Some good ideas there.

I can't tell what wood your rafters are cut from but if it is redwood or cedar, it's not the strongest thing. Adding a couple Hilti anchors into the block wall on each side would help, if you are worried about it. If you sunk your lag bolts into the plate on top of the wall and not sideways through the rafters, it's not all that stout. I can't tell much from the photos either.

JR

[SpeedracerIndy]

Thanks for the opinions guys. I'll try to answer some questions:

rick-i: Yes, the 3/8" lag is going into the 1 1/2" wide part of the 2x6. I pre-drilled the board, else it definitely would have split.

porsche4life: Yes, I could drill the blocks, but I wanted it as high as possible so I used the wood at the top. I did drill the blocks and anchor into them at the bottoms. Hard to see from the pictures. Those bolts at the bottoms aren't really taking any load though since the angle of the tires is causing the rack to want to tilt forward.

stomachmonkey: What the heck is mighty putty?

Milt: The bolts are indeed at a right angle to the load. The bottom rod isn't maxed out, it just looks that way. I ran a center support from that rod up to the rafters. When I screwed in the lag bolt securing that center support it pulled the rod back just slightly so that it looks like it's sagging. It's actually up a little higher in the center (~1/4") because of that support.

Amail: I appreciate you're critique. I'm having trouble visualizing what your saying by adding a diagonal leg to the cross pipe. I have a center support between the two tires at the center that's holding the rod in the middle already. I think that is what you're referring to. Also, I have the extra angle iron extending past the diagonal support because my rod that holds the tires is adjustable. I have wing nuts holding it on. My summer tires are bigger than my winter tires so in the winter, I have to move the rod out to the end to fit the summer wheels. Plus, I'm short (5'8") so, hitting my head on it won't be an issue. It actually is right at 8' from the ground, so unless you decided to jump up and down, just about anyone is pretty safe from hitting their head.

I think I need better pictures. I'll have to take some when I get home from work with a real digital camera.

[stomachmonkey]

Originally Posted by SpeedracerIndy

stomachmonkey: What the heck is mighty putty?

That should have been green.

Sorry.

Mighty Putty.

[David]

I'd conservatively rate it at 422 lbs.

[jyl]

If the 3/8" diameter lag bolt is stressed in shear (load applied at 90 deg to the bolt, and the bolt is screwed down tight so that it really is a shear load not a bending load), then the bolt itself should be more than fine. You can look up the shear strength of 3/8" diam steel bolt, it is far more than the weight of some wheels.

True, you never know about the crappy made-in-China bolts you buy at Home Depot. But you've got three bolts, I think, so some redundancy already.

The strength of the wood and the placement of the bolt is the question mark. Hopefully you have plenty of wood between the bolt and the lower edge of the 2"x6" and the wood isn't soft.

I would consider adding another rod, or anchoring the vertical angle iron to the wall, though. I can't tell exactly, but isn't the lower part of the rack free to swing away from the wall, pivoting on the lag bolts? If it were to swing out a couple inches, won't the wheels just drop right down, between the wall and the existing rod?

[rick-l]

I'd be worried about the plate splitting over time and the lag bolt pulling out. Is there a way you could make a bracket that attaches to your angle and fastens to the plate in 4-5 places extending about a foot to each side? That way you would not have a single point failure and distribute the load. Is the plate anchored to the block wall.

Something like a 1 1/2" wide x 2 ' x 1/8" steel with holes for 1 1/2 wood screws?

What does a wheel and tire weigh?

[rick-l]

Originally Posted by jyl

If the 3/8" diameter lag bolt is stressed in shear (load applied at 90 deg to the bolt, and the bolt is screwed down tight so that it really is a shear load not a bending load), then the bolt itself should be more than fine. You can look up the shear strength of 3/8" diam steel bolt, it is far more than the weight of some wheels.

If you look at the pictures it seems like the tires rest on the bottom bar and against the wall. the bottom angle is not supporting much and the force on the top is at 45 deg away from the wall.

This might not be in shear.

[Amail]

Originally Posted by SpeedracerIndy

In the photo, you see the diagonal brace attach to the horizontal leg about four holes outboard of the support pipe. The pipe is attached with a wing nut, and the diagonal brace is attached with a bolt and nut (I'm guessing).

If you disconnect the diagonal brace from its current hole and lose the bolt and nut, you can rotate the brace down to align with the support pipe hole and use the wing nuts to attach the diagonal AND the support pipe to the horizontal leg.

I hope this makes sense.

[jyl]

Originally Posted by rick-l

If you look at the pictures it seems like the tires rest on the bottom bar and against the wall. the bottom angle is not supporting much and the force on the top is at 45 deg away from the wall.

This might not be in shear.

I'm assuming the lag bolts are positioned parallel to the bottom bar?

I do agree the last few inches of the horizontal angle iron does nothing and is a risk to eyes, head, face, etc. At least put a tennis ball on each end.

BTW, what the bottom round bar made of? Is it a long threaded rod, passed through some pipe sections, with a wing nut on each end? Might want to think about its strength. Also, if the round bar is free to rotate, then that adds to the concern about the wheels faling down between the bar and the wall, should the rack move out from the wall.

[Amail]

Run a second support pipe behind the wheels so that they do not rely on the wall as part of their support. This way there's no question of the loads on the frame.

[Moses]

That will hold tight for at least 258 years. I'm sure of it.

Seriously though, it looks completely fine.