About Drennen Custom Contracting
Drennen Custom Contracting is a Fort Collins general contractor that has served Northern Colorado since 1973 and works as both a roofer and a radon contractor. Its licensed radon division tests buildings and designs mitigation systems for homes, real estate transactions, new construction, multifamily properties, schools and commercial facilities. Most residential systems use active soil depressurization with a fan beneath the slab or beneath a sealed crawl-space membrane, and the company also does passive activation, repairs and documented post-mitigation results. Warranties are included, and free estimates are offered. Roofing work includes replacement, repair, Class 4 impact-resistant systems and inspections, plus remodeling. Rated 5 from 440 Google reviews, 434 of them five stars and 1 one star. The company is licensed and insured, and its offices can be reached at (970) 482-9100. Realtor and builder pages cover real estate documentation and new construction radon planning.
Services and details
Installs radon mitigation systems
YesRadon testing
YesSub-slab depressurization
YesCrawlspace systems
YesNew construction
YesCommercial and multifamily
YesReal estate transactions
YesPost-mitigation test
YesWarranty or guarantee
YesRepairs existing systems
YesFree estimates
YesColorado radon license shown
Yes
Contact
- (970) 482-9100
- 608 E Trilby Rd, Fort Collins, CO 80525
- Website
- View on Google Maps
Listing compiled from public sources on 2026-11-04. Report a correction or request removal. Back to radon contractors in Fort Collins.