# Core bore



## dmar2053 (Feb 6, 2013)

We are starting a job where the floors have 2in of wood then 12 to 14in of concrete, old building. Has anyone every used their core bore to drill through the wood or do you suggest using a hole saw first? We have to drill probably 1000 holes.


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## Nathan901 (Feb 11, 2012)

I would get really tired of smelling burning wood after the 2nd or 3rd hole.


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## Kleinfelterj (Jan 23, 2012)

I've drill wood with a core bit already. It works but it's not ideal. Especially not for a 1000 holes. I'm talking one or two holes it's not to bad. I'd be calling drive core or someone that specializes in hole boring


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## Michaelcookplum (May 1, 2011)

1000 holes really, you should just quit


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## Cajunhiker (Dec 14, 2009)

That's a whole lot of holes. 
I would say go with hole-saw bits, then core through cement. Obviously, you're gonna burn through quite a few of them.


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## dmar2053 (Feb 6, 2013)

Michaelcookplum said:


> 1000 holes really, you should just quit


Not to sure what you mean by that???


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## Flyout95 (Apr 13, 2012)

sub it out, it'll be faster and they'll figure it out.


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## Mykeeb33 (Mar 6, 2015)

With that many holes, I'm sure you've already compared the cost of subbing it out vs. having your own guys (apprentice) doing it. I imagine there would be quite a problem managing the slurry as it more then likely wouldn't float up through the wood. As for the wood, contact your core drill supplier, and see what they suggest. You will be buying a few of them!


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## Workhorseplmg (Apr 10, 2013)

I would put an apprentice on drilling 3/8 holes all the way through. Then use a hole saw on the wood a little bigger than your core bit, then drill the core from the concrete side. This can all be done by an apprentice by themselves. I bet you can do it for a 1/4 of what you could sub it out for.


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## AWWGH (May 2, 2011)

What size holes? If you have the cheap enough labor then do it yourself I saw. It's not rocket science, as plumbers we drill wood and concrete every day, you just happen to have 1000 of them. Have you journeyman mark the holes, have one apprentice drill wood, one drill concrete. If you don't have the labor and you are busy don't waste time tying up a journeyman to pop holes in the floor and sub it out.

It's going to suck for whoever does it, the question is it profitable?


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## Workhorseplmg (Apr 10, 2013)

I guarantee if I had to drill a 1000 holes with a core bit that it would be $$$$$


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## wyrickmech (Mar 16, 2013)

We normally sub it out they have the training and equipment like speed bits which will cut the wood without damaging the bit. Also it keeps from tying up your manpower.


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## TC27 (Mar 10, 2012)

We had a job with roughly 750 holes varying between 3" and 12" in an older building. 2 layers of 3/4" plywood and 20" of speed tile garbage. Core drill it, anchor the drill with lag bolts using an impact gun. Go dry thru the wood, which will smell like burnt wood, knock the wood slug out and then drill it with water.


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