small diameter concrete fasteners for cladding

[NorthCivil]

I am regularily engineering claddings (light weight, regularly fastened back to building). low loads (wind governed). sometimes fixed back to concrete superstructure.

The go to historically has been to use 10 or 12 gauge screws with nylon plugs. though in recent years the suppliers of these nylon plugs have been adding disclaimers, that supporting even lightweight claddings is not an appropriate use of their nylon anchor product. (Hilti, Ramset).

the alternatives offered by the big players, are M6 diameter screw anchors, the likes of hilti HUS or ramset ANKA screws. Aside from these being very expensive, the size of these is too large to make work with a lot of cladding products without alterations that make the contractors grumble.

Is anyone aware of any small diameter (5mm or less) fasteners for use into concrete that have support from the fastener supplier? would be nice if there is an ETA report for the fastener... even nicer if the fastener is rated for post seismic performance in cracked concrete.

I dont mind if they are european, american, whatever. if there is something good out there, i know tons of distributors that would be happy to bring them in.

 

[Ingenuity]

What about HILTI KWIK-CON II in 3/16" diameter (4.76 mm, so just under your 5mm max requirement)?

They come in an arrangement of head-types, in both carbon and stainless steel.

Not too sure if they have ICC-ESR report.

 

[NorthCivil]

Thanks for the response

KWIK CON II aren't rated for seismic though,

 

[brut3]

I work in the same specialty as you do. The anchor size that you're looking for is going to be extremely difficult to find, especially if your looking for approved fasteners in cracked concrete. I don't think that you're going to be able to find 3/16" diameter fasteners though. I know there are other manufacturers that make post installed concrete screw anchors but ITW Ramset has seismically rated fasteners. Check out the link

https://www.tapcon.com/landing-page/.

 

[DBronson]

NorthCivil:

I assume you've looked at Zamac type fasteners? Pretty quick and easy to install. Link

Regards,
DB

 

[dik]

Can you use Tapcons?

-----*****-----
So strange to see the singularity approaching while the entire planet is rapidly turning into a hellscape. -John Coates

-Dik

 

[NorthCivil]

Thanks for your replies

Tapcons - specifically the 3/16" diameter look like a good option. they dont advertise any compliance on their website, i will have to chase down a technical rep.

those "zamac" fasteners, or drop-pins, pin drive anchors, as they are known around here, are popular with the local bricklayers but they give me the heeby jeebies, not appropriate in my opinion. when i used to practice overseas in a different seismic environment they were explicitly banned by the authority for any applications requiring post seismic performance. For good reason too. they are a friction fit anchor with a smooth bearing surface. and 0 cracked concrete performance I imagine.

 

[Ingenuity]

Tapcons - specifically the 3/16" diameter look like a good option.

I would use a HILTI KWIK-CON II before I would use a TAPCON.

Here is an image of 1/4" dia x 4" long TAPCON and 1/4" dia x 4" long KWIK-CON II.

Notice the difference on the shank diameter and thread type.

I have conducted load pull-tests of both types and KWIK-CON has superior capacity - even in cracked concrete.

HILTI screw anchors are more expensive compared to TAPCON.

 

[dik]

To me, it's not the dia. but the safe load capacity... are you sure the Tapcon is 1/4" and not 3/16"? I've used Tapcons for years and find them OK.

-----*****-----
So strange to see the singularity approaching while the entire planet is rapidly turning into a hellscape. -John Coates

-Dik

 

[Ingenuity]

Nope. Tapcon was confirmed as 1/4" dia - from the box of 100.

Respectively, whilst you may have been 'specifying' Tapcons for years, you may not have 'used' them for years. The difference being that many times an installer shear-offs the shank on Tapcons before they are fully-seated. I switched to HILTI due to this very problem decades ago, besides their lower pull-out capacity.

And, no I do not work for HILTI

 

[dik]

I've used them for years, too... you have to make sure they don't 'bottom out'. I've not twisted one off, yet.

-----*****-----
So strange to see the singularity approaching while the entire planet is rapidly turning into a hellscape. -John Coates

-Dik

 

[XR250]

Agree with Ingenuity. Personal experience here - Tapcons will shear off - KwikCons won't. A 1/4"Ø KwikCon is also def. larger than a 1/4" Tapcon.

 

[Ingenuity]

Thanks XR250.

I am just checking with my HILTI tech rep why there is NOT a ICC-ESR on Kwik Con's.

Tapcons ICC-ESR are evaluated for uncracked concrete only.

 

[Ingenuity]

 

[brut3]

I had mentioned it earlier in the thread. But ITW Redhead makes a Tapcon + product which is rated for use in cracked and uncracked concrete. The diameters of these anchors range from 1/4" - 1/2". I'm sure there are other small diameter concrete screw anchors out there rated for both cracked and uncracked, but here is a link to their ES Report.

https://www.itwredhead.com/portals/0/fmproductcatalog/documents/products/108/esr3699.pdf

 

[XR250]

I actually used 1/4" Ø Kwikcons on my first house instead of anchor bolts. Might not have been the best idea but it seems to work.

 

[NorthCivil]

re: earlier comments about head snapping off.

In a past life i spent a lot of time with a screwgun/drill, mostly with #10 or #12 fasteners. mostly between aluminum and steel components. I have experienced this phenomena of heads shearing off of the shank. though usually with cheap bulk ordered imported fasteners, and improper torque settings on the gun.

i would expect a 3/16" fastener to be more prone to the shearing of the head from the shank of the fastener, compared to a 1/4" fastener.

but would imagine avoiding this comes down to correct gun settings, and if screwing into concrete, correct pre-bore hole size & even hole prep (using a little brush or similar to remove debris)