Drilling Concrete Floor

[Damian30]

Hi,

I'm trying to drill my concrete floor to enable me to screw down some plywood.

I am trying to drill to a depth of 60mm, with a 8mm masonary drill bit. I've been using the hammer action, medium to fast setting and had no real problems with the 5mm pilot. However, I've now burnt out a couple of drill pits. The floor is pretty tough in places, perhaps I am pressing too hard or trying to drill a too big a hole, but any advice from somebody who has experience in this area would be very much appreciated.

Many thanks - I'm getting desperate...

Damian

 

[JohnD]

Why 60mm? Is someone going to try to lever the floor up, or do you have antigravity in your house?


If the concrete is damp (and you might have gone through the DPC) it sems to lubricate the drill with a wet cement slurry instead of cutting into it. Or the concrete might have a hard flinty aggregate, or you might have hit steel reinforcement.

I think you need a bigger, slower drill and a shallower hole.

 

[Damian30]

Hi,

Thanks for the reply.

It was suggested on another forum that I should screw down with 75mm screws to hold the 19mm tight to the floor (laying solid oak over the top).

Would an SDS drill be a better option?

Thanks,

Damian

 

[noseall]

never buy anything other than sds mutch greater impact power. incidently 7mm drill bit is ideal for standard brown plugs.

 

[JohnD]

Hi,

It was suggested on another forum that I should screw down with 75mm screws to hold the 19mm tight to the floor (laying solid oak over the top).

Damian

seems excessive to me, I'd have thought it could float, but I'm not a floor enthusiast. Is it very uneven, then?