Concrete Drilling: Verify the Hole and Breakthrough

A 5–10 minute crew discussion, plus time to verify the actual controls. The crew talk and Word version are public. Separate supervisor and attendance records are included with free Safety & Systems membership.

Why this matters

A drill can contact a concealed service, twist in the operator's hands or release a core onto someone below. Establish the hole, support and breakthrough plan before the bit turns.

Learning objective

Confirm the authorized hole and verify tool support, dust control and far-side protection.

Key hazards or failure points

Concealed services or post-tensioning; torque reaction; loose drill stand; falling core; breakthrough debris; silica; water and electricity.

Practical controls

• Resolve services and structural restrictions for the hole location, depth and any stand-anchor holes. Obtain required technical authorization; do not treat a clear scan as permission to drill blindly.
• Use the correct drill, bit, handles and fastening arrangement. Set up stable control of a hand-held tool or the approved stand support for rig-mounted work.
• Protect the far side and area below. Plan core control before breakthrough, and use the silica and water/electrical arrangements for the actual drilling method.

Verify It in the Field

• Match the hole and depth to the release information and confirm the far side is controlled. Identify who maintains that protection while work proceeds.
• In the prescribed safe state, inspect bit retention, handles and support. For a stand, verify fastening, substrate suitability and any required vacuum indication or backup against its instructions.
• Confirm the applicable dust or water system works by its prescribed check. Record the source, actual result, checker and time; do not use a person to catch a falling core.

Stop and reassess

Hold for an unknown target, changed hole, uncontrolled far side, loose stand, deteriorating vacuum, jammed bit or failed dust/water protection. Switch off safely for binding; follow the isolation and recovery procedure rather than forcing a restart.

Crew discussion questions

• What evidence covers this hole and any anchor holes?
• How is the core or breakthrough area controlled?
• What confirms this support and dust-control setup is ready?

For each required control, record its acceptance source and criterion, safe verification method, responsible checker, actual result and time. Use VERIFIED, HOLD/NOT VERIFIED, or N/A with a reason. A tick alone is not evidence. Complete all applicable task inspections; do not enter danger or improvise a test to fill out a form.

Leader preparation and practical detail

Include every penetration

Illustrative situation: the core hole is covered by the survey but the drill stand needs an anchor outside that area. The operator holds setup until that penetration is included in the services and structural review. A permit for one hole does not clear the whole slab.

Distinguish drilling systems

OSHA Table 1 treats rig-mounted core drills differently from handheld and stand-mounted drills, including impact and rotary hammers. The latter entry specifies shroud/cowling and dust collection, with HEPA vacuuming for hole cleanup. Do not put water on a hammer drill unless the actual equipment and method permit it. Anchor installation and its prescribed hole-cleaning steps remain a separate technical procedure.

A stand needs a verified attachment

The Hilti core-drill manual consulted describes model-specific fastening and vacuum limitations. Check the actual stand, substrate, orientation and instructions; do not adopt another model's vacuum pressure or anchorage detail. Identify who monitors a vacuum system and what triggers a stop. No generic pull test or fastening specification is supplied here.

Control water and the exit side

Core retention, barriers and water collection must be arranged before breakthrough. Keep people out from beneath the core and protect adjacent occupied areas. For wet equipment, verify required electrical protection and its prescribed function check. The cited Hilti models have specific safety devices; do not assume every tool has the same system. Isolate before adjustment, bit changes or core removal.

Short supervisor field check

• Match the hole and depth to the release information and confirm the far side is controlled. Identify who maintains that protection while work proceeds.
• In the prescribed safe state, inspect bit retention, handles and support. For a stand, verify fastening, substrate suitability and any required vacuum indication or backup against its instructions.
• Confirm the applicable dust or water system works by its prescribed check. Record the source, actual result, checker and time; do not use a person to catch a falling core.

Confirm the relevant trained/authorized people, unresolved items, interim protection, correction owner and recheck. Record required release authority and rebrief anyone affected. The separate sheet supports these records; it does not replace a specialist inspection, permit or engineering determination.

Attendance and follow-through

Use the separate attendance sheet for participants, roles, discussion concerns, actions and late-arrival rebriefs. Attendance is not proof of competence, functioning controls or authorization to work. Keep completed records private under employer procedures.

Technical scope and references

Reviewed October 9, 2026 for construction crew preparation. Apply the actual task, jurisdiction and relevant standard provisions. Manufacturer sources below are reference examples, not approval of your equipment. No site-specific design, permit, exposure assessment, product SDS or current model manual was supplied; obtain the applicable documents before work. This discussion does not replace required training.

1. OSHA 1926.1153 — Construction silica; distinguish Table 1 drilling tasks.
2. OSHA 1926.416(a) — Concealed electrical hazards and protective measures.
3. OSHA 1926.404(b)(1) — Construction ground-fault/grounding provisions; apply their scope.
4. Hilti DD150-U 03 operating instructions — Selected safety sections, document 2204401; model-specific core-drilling guidance.
5. Hilti TE30-22 generation 04 instructions — Selected safety and preparation sections, document 2474030; model-specific rotary-hammer guidance.
6. Hilti detection-system applications — Manufacturer guidance on embedded services and reinforcement; not US law.

Connect this discussion to your JHA/JSA

Use the related worked JHA/JSA/AHA example to prepare task steps, hazards and controls. Return to What Changed Today? when the plan or conditions change.

Related Todd Jerome Jenkins article: How to Conduct a Job Safety Analysis.

Related crew discussions

• Silica Dust Controls
• Concrete Saw Safety

Put one check into practice

Use the free JHA/JSA planning and field-verification worksheet to record today’s change, the required protection and the evidence needed before exposure.