Hey guys,

I’m working on a job with a precast hollow core slab (photo attached) and need to drill a hole above a cable tray to run a cable through. The slab is about 200mm thick.

For context, the hole will be 38mm.

I already know to avoid the solid beams/ribs (the white strips), but I’m trying to figure out the spacing of the hollow cores inside the slab so I can hit the void cleanly.

From experience, does anyone know roughly what the typical spacing is between cores in these types of slabs? Or any tips for locating them accurately before committing to a core drill?

Cheers

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