A friend is constructing his benchwork shelf fashion, and hopes to attach it to concrete walls using wooden brackets with angled braces-to achieve a legless structure. What would be the best method of attaching this type of benchwork to a concrete basemen wall? Are special drill bits required? What kind of mounting hardware would work well?
I drywalled and made stud walls from wood against the concrete block with insulation, cost some bucks but keeps the dust and cold out. other wise you need to make sure you drill out the block with concrete drill bits and a hammer drill (prevents concrete block from just crumbling). Then glue in plastic molley’s or wood dowls with an all purpose cement or concrete putty, let them dry then drill a small guide hole for the wood or plastic fastener to anchor your shelf bracket. I would use steel brackets and 2.5 inch screws. I like the Home Depot shelf kits, they have the heavy duty type with 2 tabs for heavy loads. I can support up to 30 lbs, 23 inches away from the wall.
Use a masonry bit of the proper size for your fasteners. A hammer drill makes it go a lot better but you can drill concrete with a regular drill eventually. Not sure about block walls though. In block stay away from the “mortar” in between the blocks. Try to only drill into the webbing of the blocks. I really like Tapcons for concrete fasteners. No inserts to put in the holes and they hold well. Drill and screw. Nice and easy.
Make sure you use a concrete drill bit and lead anchors, if you can still get lead anchors. A masonry drill bit will not work in concrete. I burned one up thinking that it would.
[tup] on tap-cons. Available at almost all hardware stores. Not cheap compared to standard screws though. A box of 100 1/4"x 2 1/2" runs about $18 USD. But the come with the bit and driver and you have a durable plastic box with lid when you use them all. The key with these screws is to drill the hole at least 1/2" to 1" deeper than the length of the screw that will actually go into the block (2" screw holding a 1/8" thick bracket means you need a hole at least 2 1/2" deep, A peice of electrical tape wrapped around the bit at the desired point makes a great indicator) and also if using a drill with a screwdriver tip GO SLOW! As the screw tightens against the wall you need to go even slower. It is fairly easy (depending on the strength of your drill) to strip out the hole.
I use tap-cons wherever possible at home. Perhaps buy a small quanity and practice in a out-of-sight portion of your wall to get the hang of it.
I will also strongly recommend the TapCon fasteners…I use them to install inmate phones in the cell blocks at the county jail; if they can stand up to the abuse the animals (I mean inmates) throw at them, they will hold a layout up on a concrete wall.
Don Z.
Forgot to add-
as stated before stay away from the mortar joints and use 1/4" screws, not the 3/16". 3/16" screws are decent for concrete but suck in a block wall application.
Tap-con screws work well. And are probaby your best bet.
If the walls are solid concrete, and you have access to one, you could also use a Ram-set gun (my favorite). But don’t try it on a block wall, you’ll blow the nails right through the block.
Nick
Also agree on the 1/4" Tapcons. They work best if hole drilled with hammer drill especially for poured concrete. Masonry bits in a standard drill tend to walk if you hit the stone and the Tapcon may not grab as tight.