Tapcon screws & concrete block?
 

Joe J wrote:
I'm going to be building some heavy duty shelves in the basement,
attached to concrete block. The horizontal supports will be 2x4s, with
5/8 material for shelves.
My plan was to attach the 2x4s to the block using tapcons. Pre-drill
through the 2x4s, then since the longest length tapcons I can find are 2
3/4, I was going to counter sink them into the 2x4 about 1/2".
Here is the question. Am I better off going into the block, or the
mortar joint? I've got a hammer drill, so that isn't an issue. I'm
thinking into the block, rather than the mortar, would be a stronger
fit. Each set of shelves will be 8' long, 2' wide. I was going to use
5 tapcons per 8' section into the wall.
Open to suggestions. I've built these same shelves every house we've
lived in, but in the garage attached to the studs. First time trying
with concrete block.

Thanks,

Sounds good to me, going into the block not the mortar. I built mine
the same way. Only thing is my block was filled with concrete every 2
feet so it would actually be difficult to get a Tapcon to strip. If
none of your blocks are filled, just go easy and not too much pressure
with the hammer drill. And if you get one here and there that don't
hold well, just drill again a few inches over. Or, I hear people have
very good results with loose holes by inserting a piece of 12 or 14
gauge copper wire then screwing the tapcon in again. So hopefully you
have some extra romex around.