drilling in new concrete

[Comboverfish]

Hi,

I just used a portland-based fortified concrete as a morter to pack around and support a new outdoor sillcock watervalve. It's pretty strong on its own but I would like to use tapcon concrete screws in the flange holes for added strength.

Is it OK to drill day old concrete to make the drilling operation easier, then wait for it to fully set to install screws ---- or to just wait until fully cured and drill conventionally?

Thanks for your time!

[Comboverfish]

Thanks for the quick reply. Seems like good advice.

[Travis Jordan]

I'd wait. A good 5/32 or 3/16 (depending on Tapcon size) will go through even cured concrete like butter. Well, almost.

[scott_z500]

"It'd probably be OK, but I'd wait. Since the concrete is so new, you're likely to crack it in a big way, or chew a much larger hole than you intended."

I'n no expert, but this is exactly what I was thinking.

[raven]

It'd probably be OK, but I'd wait. Since the concrete is so new, you're likely to crack it in a big way, or chew a much larger hole than you intended.

The real thing is that you should have a hammer drill, so that you don't think that drilling in concrete is a tough job that you're tempted to find workarounds.

John

[Comboverfish]

Thanks John and Scott Z for the replies. I have a crappy hammer drill from Harbor Freight that will do small diameter drilling OK. It's no big deal to wait but I was interested in the theory of drilling new concrete.