# Tapcons not grabbing cinder block



## nateshirk

I'm using 3/16"x 2-3/4" tapcons through a 2x3 and into cinder block. I'm using the bit that came with them (which seems a tad too big). They don't even start to grab. They just spin. Could the bit be too big? Would a bigger tapcon help, or would that crumble the block too?


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## joecaption

May want to share what it is your trying to do.
Any wood in contact with a block wall needed to be pressure treated.

I try to hit the mortar not the block and mostly use the 1/4 screws and always predrill the wood for a clearance hole in the wood.
If there's no predrilled hole the screw tries to push the wood away from the wall.


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## stadry

tapcons are for conc, not ' cinder block ',,, don't expect much pullout strength & expect reduced shear strength,,, those blocks have little strength other'n compressive strength ( holding up weight such as a house ! )

depending on your task, you may wish to attach a 2x4 supported by the conc floor using lead shield lags just to stabilize the 2x4


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## concretemasonry

There is a falicy about not having untreated wood in contact.

The actual requirement only applies to concrete that is in contact with the soil or actual water. It is allowed in masonry cavity walls above grade and is used on many high rise concrete structures.

It just takes a little common sense and not a blanket standard.

Dick


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## joed

Definitely sounds like the holes are too big.I have successfully used tapcons into concrete blocks many times. The blocks are harder than the mortar and give better results in my experience.


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## ben's plumbing

you will be disapointed when using tapcons on cinder block....won't hold ..ben sr


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## concretemasonry

The strength of block can vary widely since the standards (ASTM, etc.) are so low. For a good manufacturer, the strength is not a problem and they usually about 30% to 50% over the minimums because it actually is more costly to make a weak block. Water (not cement) is cheapest way to make a stronger block, but a good contractor will not accept that because dimension uniformity is the way to get economical walls.

Usually, the aggregate gradation will control the ability to hold a threaded anchor. Some aggregate types are better than others, but few block are made for nailing into.

Dick


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## danpik

.........


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## nateshirk

Why do threads go so far off track? Can I just get some good, solid ideas on how to secure some lumber to a block wall?


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## Oso954

You might want to mention why you are trying to attach them. Hanging tools, putting up dry wall, building shelves for heavy weights, etc.

It might make a difference.


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## Red Squirrel

I gave up trying to use tapcons, I find they're too hit and miss. Some will grab but most wont. 

Look at powder actuated tools, or even construction adhesive like PL premium. That stuff holds VERY well. Downside is it takes a while to cure so you can't exactly afix something and put weight on it right away, and as much as it does hold well I would not trust it for anything that has to hold people. (ex: if you have a very tall cinder block wall I would not make a second floor with only adhesive!) Then again I would not trust tapcons for that either...

For solid concrete I like to use wedge anchors. More expensive per unit than tapcons but they go in faster and hold much better.


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## stadry

you're from philly, right ?,,, ' threads go so far off track? ,,,some good, solid ideas on how to secure some lumber to a block wall? ' gosh, thought we had list'd some good stuff :yes: lead shield lags, pl const adhesive,,, we forgot conc nails ( hardened steel ) & boogers :laughing: then again, you never said what you were trying to accomplish :huh:


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## danpik

nateshirk said:


> Why do threads go so far off track? Can I just get some good, solid ideas on how to secure some lumber to a block wall?


 It is called thread drift. Happens sometimes. I deleted the drift that I made. Sorry.


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## danpik

something to understand about tapcons. The method and tools used to drill the hole are important. If you have a slow drill or a dull bit the extra time the bit stays in the hole actually can make it bigger from the erosion of the dust working its way out of the hole. Also, you need to make sure you are drilling straight into the hole and not moving the bit around as you drill. Setting the screw is equally important when it comes to the proper tool. I can never get a screw to hold properly if I use a slow speed driver. I found my Makita Screw gun to work best. If you use a slow speed drill or cordless, it can cause the screw to act as a drill bit and ream out the hole as it goes in.


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## nateshirk

I will be securing drywall to the 2x3's. I need something that will sit flush or below the wood. I know.....the moisture is already taken care of. I just figured if I mentioned that I need something to do the job that a tapcon should be doing, that would be all the info needed.


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## stadry

IF they're cinder blocks, tapcons won't work,,, i'd probably use hardened conc nails & pl adhesive


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## joecaption

The wood should not be attached directly out to the concrete.
You should be building a 2 X 4 wall out away from the block.

Some reasons why:
How would you install boxes and run the wiring?
There will be no thermal break.
They may rot due to moisture.


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## hammerlane

danpik said:


> Also, you need to make sure you are drilling straight into the hole and not moving the bit around as you drill.


I agree with danpik. Method of setting tapcons even into hollow block is important. First and foremost when drilling, make sure you do not let the bit walk around the hole. Clean the hole out of dust before inserting the anchor and when setting the anchor dont let it turn too fast or overtorque it.

Here are some other fastening options.


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## jponto07

joecaption said:


> The wood should not be attached directly out to the concrete.
> You should be building a 2 X 4 wall out away from the block.
> 
> Some reasons why:
> How would you install boxes and run the wiring?
> There will be no thermal break.
> They may rot due to moisture.


+1 on all of this!

You only need about an inch or so between the back side of the 2x4 wall and the existing masonry wall.


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## Anti-wingnut

nateshirk said:


> Why do threads go so far off track? Can I just get some good, solid ideas on how to secure some lumber to a block wall?


Substitue the "internet" for "Chinatown". It's just the way it is. You get what you pay for.
http://www.youtube.com/watch?v=1v_BVNGAfYM


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## nateshirk

As I already said, the moisture is taken care of. I'm not asking how to build a wall. I cannot build it thick enough to frame a normal 2x4 wall. 2" Foam is going down first, except under the wood. A 1/2 inch piece of foam is going under the 2x3, so it all sits flush. 

I'm drilling straight through the block. Nothing should be sitting in the hole. I'm not reeming it. I take the tapcon and screw it in, not fast or slow. It just spins straight through, and never even tries to grab the block.


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## Anti-wingnut

I'd use this:
http://www.clarkdietrich.com/products/drywall-framing/z-furring-channel

And attach with these:
http://www.fastenal.com/web/products/details/50505


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## hammerlane

A 3/16" tapcon should be using a 5/32" bit for its hole. Verify your bit is 5/32


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## jponto07

nateshirk said:


> I'm drilling straight through the block. Nothing should be sitting in the hole. I'm not reeming it. I take the tapcon and screw it in, not fast or slow. It just spins straight through, and never even tries to grab the block.


Either your block is exceptionally brittle and crumbling as you are drilling, your bit is bent causing it to open the hole wider than the bit itself or you aren't holding the drill as steady as you thought. Otherwise, your hole would be okay.

Just out of curiosity, what kind of drill and bit are you using?


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## rustyjames

Forget Tapcons in "cinder" block, ain't happening with any degree of comfort. The hammer type ones Anti showed sometimes work. I'd try the double cinch expansion or a toggle, forget sleeve anchors and powder actuated fasteners too. Cinder block is the worst material to fasten too, been down that road.


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## stadry

GUYS !!!!!!!!!!!! they're cinder ' according to the op,,, not even as strong as conc blocks,,, maybe not all that many have ever seen a cinder block :huh: IF the op needs, use a toggle - use a conc nail & pl, use the conc floor & brace the other end against a top place nailed to the ceiling joists,,, hasn't enough bee said by now ? somehow i think most of us wouldda had the *^$#@%*)^&$# 2c4's in already :thumbsup:


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## stuart45

You may be able to use the dot and dab method with insulated plasterboard.
http://www.youtube.com/watch?v=LpAe75e19X0
http://www.ecotherm.co.uk/our_produ..._with_the_minimum_of_thickness/eco-liner.aspx


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## ChantryOntario

Scroll up to the pictures posted above. See the expansion anchors. Purchase some. They are excellent for cinder blocks.


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## concretemasonry

Unfortunately, few people know what a "cinder block" is and they think any block of concrete with cores (1, 2 or 3) is a cinder block, but by code it is a "concrete block" and may use actual cinders (waste product or natural cinders). The most common cinders are only found near/around old railroad lines and near some older industrial plants. - They are highly variable waste products with different properties, so only trial and error would be the best method. Real "cinder block" from 40 miles away may be totally different.

Actual concrete block are much different and the better ones are made from naturally created lightweight aggregate and are more costly and are not used for low cost uses. Natural cinders are sometimes used in architectural block and are very pricy and have good properties and uniformity.

Dick


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## BigJim

If you have screws that just spin in the hole, I find this works for me, and you can bury the screw head in the wood. Cut a length of 12/2 WG romax electrical wire about 6 inches or so long. Strip the outside insulation where you have three individual wires but leave the plastic on the individual wires. Insert one wire into the hole you drilled and bend back about 1/2 inch of the wire outside of the hole so it won't fall through. Just screw the screw in and it will hold. It has always worked for me.


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## CosmicMiami

I have used tapcons in block successfully. I have also used tapcons unsuccessfully in block.

Here's a question. If I were to use the anchors that are hammered in with a shield, what's the procedure for removing them if necessary?

Thanks. I like the idea of using the wire in the hole. I have used two part putty in larger holes with tapcons and after it cures it is rock solid.


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## stadry

you install the lead shields in the proper size hole - place whatever must be attached - start screwing in the lag,,, NEVER hammer in the lag already inserted into the shield,,, to remove, reverse procedure - screw the lag OUT,,, don't expect to save the shield, tho :no:

tapcons in CINDER block will fail more often that they'll work successfully

2part epoxy putty + a tapcon ? that's like suspenders & 2 belts, no ? :whistling2:


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## CosmicMiami

itsreallyconc said:


> NEVER hammer in the lag already inserted into the shield,,,


I know that. I was referring to the one that is hammered in.
tapcons in CINDER block will fail more often that they'll work successfully



itsreallyconc said:


> 2part epoxy putty + a tapcon ? that's like suspenders & 2 belts, no ? :whistling2:


I've done this in block when the tapcon doesn't hold snug and it works great for hanging stuff like hose reels and such on my house. Most all the construction here (see my name) is CBS. But yes, it does seem a little redundant. I would use something a little more substantial for things that carry a bigger load.


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## joed

Any anchor used in concrete should be considered permanent instal.


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## nateshirk

In the end....I used the redheads. I could only find them up to 3 inches in depth, but it was just enough to hold real nice. It only requires to be 3/4 of an inch to be embedded into the block and I had about an inch going in. Thanks for all advice.


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