That's it.

A couple of points to add to the previous post:

- a crash deck just under the core-drilled floor will stop damage to the floor beneath

- if the core is close to a column, you need to get the engineer to okay this as you will probably be cutting through some important reinforcement. 300mm will be cutting through at least 2 main bars in any one layer of reinforcement

- if you are not close to a column or beam then you will still need to ask the engineer since he has probably allowed for small diameter holes in his specification (less than 100mm diameter for example)

- 500mm slab sounds very thick and may be a transfer slab, in which case you this is another good reason to ask the engineer

Thank you to all.

Let me confirm the slab thickness once more.

You can also drill from the bottom, is a lot cleaner and can be done without creating a mess with the dirty water. (re: Hilty) And the cut piece stays in the core drill cylinder.

Hi Sandeep, 500 mm is a thick slap. You are sure you do not drill through a beam section? This is a parking garage?

Make sure you check location of core drilling, try not to cut any of the steel, or you have to check the design for loss of reinforcement. The slab thickness is too large. Never seen this on the job. Please make sure your structural engineer takes a good look!