# Mounting 2 x 4 to block wall ?

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• posted on March 11, 2008, 9:38 pm
charlie wrote:

If the 2x4's are orientated vertically and are resting on the floor, they will support most of the weight. Think of a hundred lb weight hanging on a 2x4 in free air, just your hand holding it from falling over. It will not require 100 lbs of effort on your part to stop the 2x4 from falling. the force you are exerting is not vertical, the 2x4 takes care of that. You effort is only opposing the overbalance of all load being on one side.
HeyBub may have been sober all along.
Of course the OP could add 2x4s to the front of the shelves as well and have a device that would not require any attachment to his walls at all.
LdB

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• posted on March 12, 2008, 12:51 am

OK, so suppose your 100 lbs of weight is from a shelf bracket supporting a shelf 1' wide. Let's take the worst case, that all the weight is at the front of the shelf. Then that's a moment of 100 ft-lbs.
If the shelf bracket has two fasteners into the 2x4 that are 1' apart, then the load on the top fastener is 100 lbs of tension. If you are holding the 2x4 5 ft from the ground and have the bottom end against your foot, you have to apply a tension force of 20 lbs.
Now if the 2x4 is glued to the face of the masonry wall, and is 8' long, then a tension force of 25 lbs at 4' from the bottom gives 100 ft-lbs. If the adhesive is along the entire length of the 2x4, then that's a tension load on the adhesive connection of only 3.125 lbs/ft.
Yours, Wayne

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• posted on March 11, 2008, 4:33 pm
Tapcon Screws are the best. Use the proper drill bit that is just under the thread size. Sometimes you have to work the screws in and out.......Then final tight..... 1/4 " are great............. jloomis

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• posted on March 11, 2008, 5:52 pm

Another option which may be simpler depending on your situation. If the 2X4s will run floor to ceiling, you can just rest them on the floor and use brackets and screws at the top to attach them to whatever wood is available - floor joists or sill plate. (i.e., no attachment to the block wall at all) I have put up basement shelves this way and it worked fine. I also have used a powder-charge gun to attach to the blocks and that worked fine too. -- H

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• posted on March 12, 2008, 6:12 am

TapCons of the proper length. Easy to use, and incredible pull out strength.
Steve

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• posted on March 12, 2008, 6:15 am

I answered TapCons because you said it was solid concrete. In that case, TapCons would be the thing. BUT, if you have grouted cinderblock, use sleeve anchors. These are anchors that hold in soft masonry such as cinderblock and grouted cinderblock. Just look for the particular fastener labeled "sleeve anchor" and allow for the thickness of the board, and 2" penetration into the block, which would be 4" for a good fastener.
Steve

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• posted on March 12, 2008, 10:40 am
Steve, and others:
It looks like Tapcons are ideal, if I have a solid wall. Yes , it is a cinder block wall. But, I have looked closely in my basement, and I can see concrete spillover at the top of the wall. So now, I think it has been poured solid. This cabin was built over 30 years ago, and I have forgotten some of the details.
I think that my best bet is to "assume" that this block wall was poured with concrete for reinforcement, and initially try drilling and using the Tapcon screws. If I see that it is not solid where I drill, then I could go with some type of toggle/ molly bolt, or the sleeve anchor, right ?
Thanks to Steve and to all others for the very nice comments and advice !! I have learned a lot from this group.
James

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• posted on March 12, 2008, 5:32 pm

You'll know when you drill your first one. Many times, a mix of grout was almost slurry as compared to a real mix of concrete with aggregate. I repaired a ton of gates in Las Vegas where they used sandy grout instead of a concrete mix, and the sleeve anchors were the way to go. If the Tapcon is almost squeaky tight, that's what you want. If it is looser than that, just put a lot of tapcons, or maybe add a sleeve anchor at the top and middle of the two by.
Steve

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• posted on March 12, 2008, 6:17 am

Duh, just another aside. If you use TapCons drill in the exact center, or on the edges where you will be drilling into cinderblock and not grout. If you have to drill into grout, use sleeve anchors.
Steve