Read Head Head Hammer Set Anchor

miamicuse

I have previously used Tapcon screws to attach wood (furring strips, studs, backing boards) to concrete block walls.

My experience with Tapcon is hit and miss. Sometimes the screws will bottom out and spins instead of lock tight and snugged.

Other times, I found that the screws would be driven tight into the block, holding a piece of 2x4 or 2x6. However, I am attaching other wood members to the piece of 2x4. If I am using a palm nailer or an impact driver, bang bang bang bang bang...after a while, the Tapcon would come loose a little. I can pry off the piece of 2x4 from the concrete wall.

So I tried using this hammer set anchor.



That seems to work pretty well. So far it's holding better than Tapcons.

The question I have is whether I have the right lengths.

Let's say I am attaching 2x4s to the concrete block wall. The 2x4 is 1.5" thick. The instructions says at least 0.5" embedding into the concrete. So I got 2" anchors.

However, since I will be attaching other things to the 2x4, and I need this to be flushed, I need to recess the round head of the anchor into the wood. So I drilled a 3/4" hole into the 2x4, about the depth of the anchor head, I am guessing it's about 3/8", so the anchor would protrude about 3/4" to 7/8" into the block. Is the 2" lengths good to use or should I be using 1-1/2"?

kwikfishron

I use that anchor quite frequently but I'd be using 2 1/2" myself...certainly not 1 1/2".

The key to Tapcons (for me anyway) is a clean hole drilled with a good hammer drill and a new bit.

I drill about 1/2" deeper than the screw needs and blow out the hole with air.

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Ravenworks

You could always do it the hard way and wire nail it.

miamicuse

I do the same, but still a hit and miss.

For example last week I had to attach a PT 2x4 vertically on a concrete wall. The wood is about 6' long and I decided to put in 5 screws. The top one is solid concrete where the tie beam is and the other four are blocks. I do try to drill where the webs are to get into the solid part and I also use an air canister to blow out the dust.

I recess the wood a little bit and use a hex head Tapcon screw, then I drive it in and half the time it keeps on spinning when it bottoms. You are right if I don't blow out the drilled dust this happens much more often.

But even if I drive it in tight, I found out sometimes it will sort of come loose a little if I am doing too much "vibrating" on the piece of wood. Such as nailing or impact driving other wood onto it.

The Red Head hammer set anchor seem to work MUCH better. So far no problems.

The reason I asked about the length is I was under the impression that the last 1/2" or so expands the most as you hammer it in. If I were to use 2-1/2" will the end be too far into the block to grab the sides of the wall since it is hollow?

mae-ling

I use the tapcons with the phillips head. Drill hole deeper then needed, then the head pulls down below the surface of the wood.
Are those hammer set anchors rated for the same weight/strength as a tapcon?

miamicuse

For Tapcon screws, 1/4" size with embedment of 1" in solid materials, tension is rated 750lbs and shear 900lbs.

For Hammer Set Anchors, 1/4" size with 3/4" embedment, tension is rated 880lbs and shear 970lbs.

So I would say they are comparable.

Tapcon's specs says those ratings are for embedment in "solid materials". So for concrete blocks unless you are drilling in the middle of the web it doesn't count.

My problem with Tapcon screws is movement after installation. Just seem with repetitive small movement the screws eventually come loose for blocks. For solid concrete it seems to hold much better.

miamicuse

I looked and could not find any longer than 2". Where did you find the 2.5" lengths?

Ravenworks

Why not drill a 3/16" hole (you are doing it anyhow) insert a piece of tie wire and use a # 10 sinker,it's not going anywhere and you can cut the wire flush.
You have to drill into a joint.