Concrete core drilling: the complete guide

2026-02-10 — Ottawa-Gatineau

Diamond core drilling is the clean, fast and precise way to make a hole in concrete. Here's everything a homeowner or property manager should know before requesting one.

How does it work?

An industrial drill bit embedded with diamonds spins at high speed and "grinds" the concrete in a perfect circle. Water cools the tool and captures dust — the hole is clean, crack-free, and the concrete core comes out in one piece.

Typical diameters and uses

• 1" to 2": wires, network cables, small water or gas lines
• 3" to 4": plumbing pipes, dryer vents, drains
• 5" to 8": ventilation ducts, air exchangers, sprinklers
• 10" to 14"+: technical sleeves, commercial plumbing stacks, access hatches

How much does it cost?

Questions to ask before drilling

• Are there cables or pipes in the wall/slab? (a ground-penetrating radar scan can be done)
• Is the wall structural? (a large hole in a load-bearing wall must be validated)
• Is fire caulking required after? (mandatory between floors in commercial buildings)

Horizontal vs vertical coring

We drill through walls (horizontal), through slabs (vertical), and even at angles. Vertical coring through a thick slab with rebar is a classic for adding a basement bathroom.

Need one hole or a hundred? See our coring service →