Hard Brick...

[timcgibbs]

I'm working on wrap-around porch re-build and the plans call for tapconning some 'posts' to the brick foundation directly below where the beams meet the ledger.  I use hammer drills and bits often. Tried a SDS Bosch bulldog and a Milwaukee 1/2" corded dedicated hammer drill yesterday.  The concrete bit tips just 'melt' in this brick!  It as if they just re-temper into a little metal ball bearing.  We tried multiple holes in various areas of the foundation and found the same thing over and over. 

Has anyone come across this 'uberbrick'?  And what is it's kryptonite?

 

[chrisrosenb]

I have never found a way to drill very hard bricks.
Even if I was able to drill a hole into them, I was not able to drive Tapcons into them because the threads cannot cut into the brick.
I try to drill into into the mortar joints if possible. 

 

[jvsteenb]

In many cases, it's not the wisest thing to do to place an anchor ( tapcon or otherwise ) in a mortar joint.
If the brick is extra hard baked brick and its a vertical hole top-down, you maybe succesfull using an SDS drill thats grinded to actually have an edge, using wather as a coolant and intermedium and without hammering.
You'll have to have a grinder with a hard enough stone to grind carbide..... a standard bench grinder stone just won't cut it, literally.
There are universal drills, that can be driven with an ordinary drill and that can be surprisingly efficient when used wet. DEFINATELY use a ground current triggered circuit breaker ( whatever you guys call them ).

But the best chance you probably have is using a tubular diamond core drill ( they are available as small as 1/2") and a helper with a garden hose to keep it watered. It's a bit hard to get started, though that's not so bad on small diameter drills, but once its in it's a straightforward job.  Over here you can rent this machinery and that'll be a bit easier, as they usually have a special attachment for the watersupply, and sometimes a drill support to get it in straight.

Retract the drill, remove the core, flush clean, let dry and use a chemical anchor.

Regards,

Job

 

[Deansocial]

never had a brick that i can't drill. what bits are you using? I use these http://www.us.hilti.com/holus/page/module/product/prca_rangedetail.jsf?lang=en&nodeId=-58021

 

[timcgibbs]

We finally drilled the holes! - (well, my poor young helper was on the hammer drill for 5 hours to drill as many holes. burned through about 8 bits.)  We tried Ram set shots too - nothing, they would just chip the brick.

Thanks for your good ideas. I'll keep them up the sleeve for next time!