Replies

1. 
   Guest_ | May 19, 1999 10:26pm | #1

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   I've used 2 different methods. Neither one is terribly difficult, but having a hammer drill makes both methods much easier.

   #1) Locate the mortar joints between the blocks. Use "Tapcon" screws (the brand name, they are blue) sunk into the mortar. Be sure to pre-drill the hole to the appropriate depth (it is specified in the instructions) and blow out any concrete dust.

   #2) There are a number of expansion bolts and toggle/molly -type bolts that are specially made for anchoring to the hollow part of the blocks.

   Any decent hardware store should carry these type of screws/bolts. Just make sure you use the proper lengths.

1. 
   Guest_ | May 19, 1999 11:27pm | #2

   *Hi Per SwedeI agree with your idea number 2,(It's acually my prefered method) but not idea number 1.First, the mortar is the unknown factor. It could be very brittle and hard or could be soft like a sponge.Either way, it's no place for a tapcon, better drill the web. It will hold to the full dept of the screw.Gabe

1. 
   Guest_ | May 20, 1999 02:19am | #3

   *Anyone have a pref: lag shields v. expanding sleeves/anchor bolts?

1. 
   Guest_ | May 20, 1999 03:33am | #4

   *The best way to attach to a cinderblock wall is to through-bolt it (long hex bolt, nut, and washer(s)), although this is not possible in many situations. Personally, I have found lag bolts with lag shields to be only somewhat reliable in this application. On the other hand, I once had a situation where we had to (try to) remove an expanding sleeve anchor bolt that we had set in block… we ended up cutting it off with a sawsall.

1. 
   Guest_ | May 20, 1999 03:55am | #5

   *Hi Andrew,Use them both as required, like the lag bolts better, they seem to grip easier for me.Gabe

2. 
   Guest_ | May 20, 1999 06:59am | #6

   *Be sure the anchors you choose have the correct shear strengh and proper installation for this application.

3. 
   Guest_ | May 20, 1999 09:06pm | #7

   *Concrete trivia: doesn't "cinderblock" technically mean just the very cheapest grade of CMU, not suitable for building? Anyone know the bearing strength of a hollow or solid 6x8x16?

2. 
   ChadS. | May 20, 1999 11:24pm | #8

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   ml,

   I would check into the type of block you're looking at anchoring to, as stated above by Andrew, a true cinder block is light weight and often brittle. If you decide you can bear weight on the wall, I would recommend an anchor sleeve with epoxy (SIMPSON or HILTI make them). They make a positive, solid connection to the block and typically will not pull out or work loose. Another method I've used is to remove a few whole blocks and replace them after grouting in some cells to distribute the loading.

   Good Luck!

3. 
   ml_ | May 22, 1999 07:18am | #9

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   Does anyone have a method of attaching a ledger (solidly) to a cinder block wall which is mostly hollow (ungrouted)?

   thanks.

4. 
   Guest_ | May 22, 1999 07:18am | #10

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   ml, what is the ledger for? A deck, maybe?

   If it's for a deck or a roof system, the connection will likely be in both shear and tension. I would do everything I could to through-bolt the ledger with 1/2" HDG machine bolts AND a backer of 2x treated material. The ledger itself should be treated, of course. Code folks here in VA like to see those through-bolts 16" O.C., and will not accept lags & anchors or expansive bolts in CMU walls.

   Sturdily, Steve