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Best Radon Contractors in Castle Rock, Colorado (2026)

Ranked using real Google ratings, review counts, and certification data only.

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#3

Defining Principles LLC. DBA Pillar to Post Home Inspectors

Castle Rock, CO

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Google rating: No Google rating available

Reviews: 0

Certifications: 1

Certifications

NRPP Measurement Professional

Services

Testing
Call 7208782529Visit website

#8

Aaron Woodfield

Castle Rock, CO

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Google rating: 5.0 (21 reviews)

Reviews: 21

Certifications: 1

Certifications

NRPP Mitigation Specialist

Services

MitigationCrawlspaceCommercialvapor barriersump pump
Call 3033058419Visit website

#11

Aspire Property Inspection

Castle Rock, CO

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Google rating: No Google rating available

Reviews: 0

Certifications: 1

Certifications

NRPP Measurement Professional

Services

Testing
Call 5555555555Visit website

#12

Green Door Home Inspections ltd

Castle Rock, CO

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Google rating: No Google rating available

Reviews: 0

Certifications: 1

Certifications

NRPP Measurement Professional

Services

Testing

#13

Radon Free Colorado

Castle Rock, CO

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Google rating: No Google rating available

Reviews: 0

Certifications: 1

Certifications

NRPP Mitigation Specialist

Services

Mitigation

How We Rank Contractors in Castle Rock

Our ranking methodology is transparent and data-driven. Sponsored placements are clearly labeled and appear separately — they do not influence organic ranking position.

  1. Google rating — Higher average ratings rank higher. This reflects real customer satisfaction across verified Google Business profiles.
  2. Review volume — More reviews break ties between similar ratings. A 4.8 with 50 reviews outranks a 4.8 with 3 reviews because the signal is more reliable.
  3. Certification count — NRPP and NRSB certifications break remaining ties. More certifications indicate broader competency across mitigation, measurement, and specialized techniques.
  4. Data integrity — All ranking data comes from verified sources: Google Business API, NRPP/NRSB certification databases, and contractor websites. Template-generated or unverifiable data is excluded.

Read our full methodology for details on data sourcing, verification, and quality thresholds.

Related Pages

All contractors in Castle Rock (13)All contractors in ColoradoMitigation cost in ColoradoTesting cost in ColoradoCost calculator tool

FAQ

Who is the best radon contractor in Castle Rock?

6224 Inspections is currently ranked #1 in Castle Rock based on Google rating, review volume, and certification count from our verified data sources.

How many radon contractors are in Castle Rock?

We currently list 13 radon contractors in Castle Rock, Colorado. 13 hold NRPP or NRSB certifications and 6 have Google reviews.

What should I look for when choosing a radon contractor?

Focus on strong ratings with meaningful review volume, current professional certifications (NRPP or NRSB), and clear service coverage for your home type. A good contractor will assess your specific foundation and provide a written scope that includes suction point count, pipe routing, fan specification, and post-mitigation testing.

How are these Castle Rock contractors ranked?

We rank contractors using a transparent, data-only methodology: Google rating first, review count second, and certification count third. Sponsored placements appear in a separate, clearly labeled section and do not influence organic ranking position. All ranking data comes from verified sources including Google Business profiles and national certification databases.

Should I get multiple quotes in Castle Rock?

Yes. With 13 contractors in Castle Rock, getting at least two written quotes is practical and recommended. Compare the number of suction points, fan model, pipe routing plan, warranty length, and whether post-mitigation testing is included. Price alone is not a reliable differentiator — system design matters more for long-term radon reduction.