Hi all,

I need to drill two four inch holes through my foundation wall. I'd like to avoid jack hammering and use some kind of drill or coring tool that will leave a respectable looking hole, so whats out there?

Thanks for the help

John Landy

 

your best bet is to go to your local rental store, they will have several options. there is an eletric drill that is perfect for what you need to do, it's not exactly a drill, but is made to hammer or drill thru concrete.hth's

 

John:

A core drill with a 4" bit would give the best looking hole.
To use one you would drill one or two 1/2" holes, depending on the unit. With these you would securly bolt the baseplate for the core drill and then assemble the drill. A water line connects to the drill to flush the waste concrete away and cool the bit.


Image credit: powertoolstore.com

An easier way would be to rent a rotary hammer drill with a 3/4" carbide concrete bit and a small chisel.
You could drill a series of small holes and then clean up the edges with the chisel. This is what I normally do.
If you need picture perfect holes you could find a piece of steel pipe and grout it into the hole.


image credit: powertoolstore.com

Note that some rental places won't rent a core drill to a novice as the bits cost hundreds of dollars and are easily damaged.

 

Thanks for the replys I think that I will go the multiple hole method and then clean it up by placing a thimble and re-cementing thanks again

 

Grout plastic pipe in the hole. Corrosion and rust stains can lok ugly if the pipe is exposed on the outside.

 

Be careful. If you use a hammerdrill thats powerful enough to drill thru a foundation, It will have tremendous torque.If bit jams in hole you will not be able to hold on to it. Can break arms and jaws. Hilti makes one with automatic torque control(ATC). Drill stops if bit jams. I own the TE76. It does what it says it will do. very safe.Ask for a drill with(ATC) where you rent.