Concrete coring demands precision and specialized equipment—hire the wrong contractor and you'll face costly delays, structural damage, or safety hazards. Before signing a contract, you need to ask the right questions to separate competent operators from those cutting corners. Here's what separates a solid hire from a mistake.
Does the Contractor Have the Right Equipment?
Concrete coring isn't a one-size-fits-all operation. Ask specifically what type of coring rig they own and whether it's suitable for your project's depth and diameter requirements. Wet coring rigs cool the bit with water circulation, producing cleaner cores and less dust—essential for indoor work or sensitive environments. Dry coring works in other scenarios but creates substantial dust and heat. A qualified contractor should explain why their equipment choice matches your project, not just tell you what they have available.
Also verify they own their equipment outright or have reliable access to it. Contractors renting on-demand may face availability issues if your project spans multiple days.
What's Their Experience With Your Specific Application?
Experience matters enormously. A contractor experienced in coring for HVAC penetrations through 8-inch walls differs from one specializing in fiber optic conduit runs through 12-inch concrete slabs. Ask for specific examples:
- How many similar projects have they completed?
- What's the thickest concrete they've cored through recently?
- Have they handled your building type (residential, commercial, industrial)?
- Do they have references from the past 12 months you can contact?
Request photos of completed work. Look for clean, perpendicular holes with minimal chipping around edges—that indicates operator skill and proper equipment maintenance.
Can They Navigate Code and Utility Concerns?
This is non-negotiable. Before drilling, utilities (electrical conduit, plumbing, rebar, post-tension cables) must be located and marked. Ask:
- Do they use ground-penetrating radar (GPR) or X-ray to scan before coring?
- Will they coordinate with a utility locating service?
- Who bears the cost if unmarked utilities are damaged—contractor insurance or your responsibility?
- Do they have documentation proving scanning was completed?
A contractor dismissing this step is a red flag. Hitting a live electrical line or structural reinforcement creates liability nightmares and safety risks.
What About Timeline and Cost?
Pricing for concrete coring typically ranges from $150–$400 per hole for standard residential or light commercial work, though larger diameter cores or deeper penetrations cost more. Get a written quote that specifies:
- Number and size of cores (diameter and depth)
- Whether the price includes concrete removal and cleanup
- Scanning/utility location costs (usually $200–$500 added)
- Timeline (most jobs complete in 1–3 days)
- Payment terms and deposit requirements
Ask if they charge extra for cores deeper than 12 inches or diameters exceeding 6 inches. Unusually low bids often mean corner-cutting; ask why their price undercuts competitors.
Do They Handle Permits and Inspections?
Some projects require building permits and post-coring inspections. Clarify whether the contractor will:
- Obtain necessary permits on your behalf
- Coordinate inspections
- Provide documentation for your records
- Handle fees (typically $50–$200 per permit)
Smaller residential jobs may not need permits, but commercial work often does. A knowledgeable contractor knows your local requirements without you asking.
Are They Properly Insured and Licensed?
Verify general liability insurance ($1–2 million minimum) and workers' compensation coverage. Request a Certificate of Insurance listing you as an additional insured. Confirm they hold any required state licensing—requirements vary by jurisdiction. If coring into occupied spaces, ask about dust control methods and how they'll minimize disruption.
When you're ready to hire, comparing multiple qualified contractors side-by-side saves time and money. Platforms like Mercoly let you find and compare trusted concrete cutting and coring providers in your area, making it easier to verify credentials and get competitive bids.
Frequently Asked Questions
Q: How do I know if a contractor's price is fair? Get written quotes from at least three contractors and compare scope details; typical residential coring costs $150–$400 per hole, with larger or deeper cores commanding premium pricing. Watch for quotes significantly below market rate, which often indicate inadequate insurance or corner-cutting.
Q: What happens if the contractor damages rebar or post-tension cables during coring? Their insurance should cover structural damage liability, which is why verifying coverage is critical—ask to see the policy and confirm limits. If uninsured damage occurs, you may be responsible for expensive repairs.
Q: Can any contractor handle industrial concrete coring? No—industrial projects require contractors with heavy-duty equipment and experience coring thick, reinforced concrete; always request past industrial references and verify their largest diameter and deepest penetration to date.
Get multiple quotes from vetted contractors and ask these questions before commitment.