Theisen Roofing & Siding: Protecting Cortland, IL Homes for Generations

For over 50 years, Theisen Roofing & Siding has been the trusted name for homeowners in Cortland, IL and the surrounding area. This family-owned business operates from its own 20,000 square foot facility right in town, ensuring they have the tools and team ready for any project. They focus on residential work, with a dedicated crew of trained employees who handle every job from start to finish—no subcontracting. While they primarily schedule work, they understand the urgency of storm damage and work to address urgent needs promptly for the community.

Key Roofing, Gutter, and Siding Services

Theisen Roofing & Siding offers a full suite of services to protect and enhance your home. They handle everything from routine maintenance to major replacements.

• Roofing: New roof installation, complete tear-offs, re-roofing, repairs, and thorough roof inspections.
• Gutters: Installation, cleaning, repair, and replacement of seamless gutters, plus gutter addition for better water management.
• Siding: Installation, repair, and replacement of siding to refresh your home’s exterior.
• Extras: They also install skylights to bring more natural light into your home.

Areas Served Around Northern Illinois

Theisen Roofing & Siding proudly serves a wide area of Northern Illinois. This includes Cortland, IL, DeKalb, Sycamore, Genoa, Sandwich, Maple Park, Plano, Rochelle, and many surrounding towns in DeKalb, Kendall, and Boone counties. Their long history in the region means they have a deep understanding of local housing styles and the specific challenges posed by Illinois weather, from heavy snow loads to summer storms.

A Family Story Since 1971

The company’s story began in 1971 when Ray Theisen started the business. It was built on hard work, honesty, and a commitment to doing the job right. Today, Ray’s sons, Jeff and Brian, run the company, carrying forward the same family values. They’ve grown from a small operation into a well-established local employer with a large facility, but they’ve never lost their personal touch.

Leadership and Community Roots

Jeff and Brian Theisen grew up in the business. They are not just owners; they are hands-on professionals who understand roofing and siding inside and out. Their local presence is strong. Theisen Roofing & Siding is an active member of the DeKalb Chamber of Commerce and the U.S. Chamber of Commerce, and they maintain a strong standing with the Better Business Bureau. Choosing them means supporting a business that is invested in the community’s success.

What Makes Theisen Roofing & Siding Stand Out

Several key features set this Cortland, IL company apart.

• Certified Quality: They are certified by leading manufacturers like CertainTeed, GAF, and Malarkey, which allows them to offer strong extended warranties on their work.
• Seamless Gutter Expertise: They manufacture custom 5” and 6” aluminum seamless gutters right on your property in over 20 colors that are designed not to chip or peel.
• Complete Crew: Their own trained employees do all the work. You won’t have different subcontractors showing up each day.
• Wide Material Selection: They offer many types of shingles and also provide aluminum soffit and fascia in their 20 color options.

Why Locals Trust Theisen Roofing & Siding

Homeowners and businesses across DeKalb County return to Theisen Roofing & Siding for simple reasons: reliability, quality, and a lasting local presence. When you hire them, you get a team that has been solving local roofing problems since 1971. Their quotes are free and straightforward, their work is backed by manufacturer certifications, and their commitment is to your complete satisfaction. For a roofing, gutter, or siding company that treats your home like their own, the choice for many in Cortland, IL is clear.