I'm really starting to hate TAPCONS!

[Bob Winkler]

Working on affixing my T&G subfloor to my workshop slab in preparation for an oak floor. Work has been difficult and I've snapped as many screws as I've driven successfully. I've tried all the usual remedies:

1. Used good screws from McFeely's- no luck
2. Am using a hammer drill to pilot holes
3. Tried different 3/16" drill bits, including Bosch and Tapcon. I'm using 1/4" screws. No luck
4. Tried phillips and square drive bits (screws are universal).
5. Replaced McFeely screws with genuine Tapcon which were 1/2" shorter to limit penetration to 1". This has improved things a little, but still is very random.

The most common issue is stalling of screw or snapping. The concrete is less than 2 years old, and does not have much aggregate, but is fiberglass filled.

I'm almost at the point of using concrete nails and pound away. I thought the screws would hold better. Any ideas?

Bob

[Steven Satur]

I have used Tapcons at work. They are hit and miss, some hold, some snap, some just strip out even with a torque screw gun.
What are you trying to do, attach T&G oak right to the concrete? I would try attaching sleepers first, then the T&G.

Steve

[Anthony Whitesell]

Unfortunately, I've had almost the same experience. The 3/16" Tapcon, calls for a 5/32" drill bit. I had the best luck drilling with the Bosch Blue Granite bits. I was using Philips-head and stripping the heads out as often as I was able to sink them. This last round I changed over to head head and an impact wrench with 100% of the screws sinking the first try. On the flip side I had to drill twice as many holes to get enough of them to the correct depth. Some spots of the concrete were hard and other spots quite soft. Talk about hit or miss.

Which type of hammer drill? I am using a Big Lots special ($20) rotary hammer drill, like a regular drill with a hammer action. I have often wondered if a SDS style hammer drill (the ones that work more like a impact wrench) would be more effective.

P.S. For what it's worth, the outside of the foundation drilled much easier than the inside. First hole was deep enough on every attempt.

[Bob Winkler]

I'm attaching 3/4 advantage subfloor over 1" XPS insulation. The oak gets nailed to the subfloor. I assume that sleepers would have the same attachment issues with Tapcons as the subfloor.

Bob

[Bob Winkler]

Actually, 1/4" tapcon screw calls for 3/16" bit. I'm using a Ridgid Hammer drill which is doing quite well at boring the holes. I agree, the Bosch bits work very well. Maybe I'll try lubing the screw with spray teflon to see if that prevents the galling going in.

Bob

[John Lanciani]

Hi Bob,

When putting tapcons in vertical, you need to either go about 50% deeper than the screw length or blow all of the dust out of the hole. The dust packs into the bottom of the hole and has nowhere to go otherwise. I use an SDS rotary hammer to drill, and a cordless impact driver to install. With a fresh bit and good screws - I only use real ITE/tapcons -I average about 95% success. Don't overlook the drill bits, with each hole you drill they lose diameter and after 75 or so holes they get pretty tight.

[Anthony Whitesell]

If only I had a bit that last 20% that long...I drilled 12 holes and blew away one bit, but then again I am using that cheap HF-like rotary hammer drill.

You're correct on the sizes Bob. I'm using 3/16" screws and the 5/32" bit. (I've corrected my post)

[Bob Winkler]

I'm cleaning the hole using my vacuum to suck out the debris. Tomorrow I'll try compressed air as suggested.

Regarding the drill bit, I use the Bosch drill with the hammer drill to create the hole, then use the Tapcon bit in another regular drill to do a final sizing of the hole. I am drilling the hole about 1" deeper than the screw size, but can go deeper. I'll try that too. Maybe tomorrow will be my lucky day.
Bob

[Doug Sewell]

Go rent a Hilti hammer drill. I didn't believe how good they were until I used one. I was tyring to drill with a Dewalt and was getting nowhere then switched to the Hilti and it went through 30 year old concrete like butter. Oversize the holes and GENTLY screw the screws in. DO NOT try to overpower the screws or they will snap, use the clutch on the drill and things should improve greatly.

[Roger Pozzi]

You never said what driver you are using. But, my experience with TapCons ended with me using a corded drill for driving and, NOT burping them in, keep the power on it until seated. This does take quick reflexes but every time I stopped part way in, the screw broke.
As for cleaning the hole, I just placed my vacuum hose directly on the hole and let it suck down to the floor.
This is only my opinion but, it worked very well for me.

[Bob Riefer]

I used a ramset to fasten various things to the floor in my shop (such as bottom plate on walls, stairs footer etc.). With a little liquid nails underneath, and considering that weight + gravity = a pretty not-wanting-to-move surface to begin with, this has held fast for me.

Also, I've seen many instances of wood floor install where sleepers are not fastened down with anything other than liquid nails. No mechanical fastener at all. This is how I would do it at my own shop actually - if ever the floor needs to be pulled up, the concrete is in good shape still. And in reality, with hundreds (thousands) of pounds on an interconnected structure, where's it gonna go?

edit: But if you are set on using tapcons, the above poster (Roger) is right... you can't stop for even a second with tapcons, you need to drive them with power until they're seated fully. If you stop, back it out, and take another run at it. Momentum, proper sized pilot hole, and cleaned out hole are the keys in my experience. (oh, and I'm sure this is obvious, but just in case... tapcons can take either a screw driver or a socket interface.. use the socket)

[John Coloccia]

When I buil my shop, I had the same issue with Tapcons. Every other one would snap. I started driving them with an impact driver (actually, and old electric impact wrench....cheap Kawasaki I picked up from Pep Boys) and that completely alleviated the problem.

[Steve Ryan]

I use a Bosch SDS Bulldog. Drill deeper and ream in and out with a vac nozzle right at the bit. This gets most of the dust out. I often use the sleeve that fits over the bit with the proper bit at the end to drive the screws. Often even drive the screws with the hammering action on. Other times I use a seperate driver.

[Kent A Bathurst]

Never had trouble with tapcon into block or brick, but had some snap into poured floor - so I drilled deeper, blew the holes out, AND "wiggled" the bit a little bit to create a slightly larger hole diameter - that did the trick - I have never worried about extraction resistance into the floor - gravity works the other way, even in Georgia. My guess was that there was simply no "give" left in the poured floors in my two 90-year-old basements - I think it must be fully cured by now, huh?

[Ryan Hellmer]

If you're not using an SDS, start. Life is too short for the wrong tool for the job. I drilled about 100 1/2" 3" deep holes in concrete for rebar pins using a milwaukee hawk SDS. The whole job took about an hour and I only used 1 bosch bit that was previously used and still has lots of life left. Other than that, I have never had much luck with tapcons. I either use expandable anchors or nails fired with the remington.

Ryan