Low Slope, High Standards. Flat Roofing from the Pros Who Know.
Flat roofs demand more than surface-level solutions. At Custom Installations, we treat flat roofing like the high-performance system it is — with premium materials, expert prep, and flawless integration with your building’s envelope.
Whether for a modern home addition, light commercial space, or architectural detail area, we design and install flat roofs that stand up to Chicago and Milwaukee’s harshest seasons — without compromising on curb appeal.
- Licensed, Bonded & Insured in IL & WI
- 50+ Years of Steep- and Low-Slope Roofing Expertise
- Dedicated Site Superintendents on Every Job
- Expert Drainage Design, Waterproofing & Flashing Work
Free Estimate!
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Our Certifications & Trusted Brands
Our Preferred Flat Roofing Solutions
We work with industry-trusted materials and membranes that offer long-term protection and proven performance.
Modified Bitumen Systems
Ideal for residential and light commercial builds, offering durability and ease of maintenance.
EPDM (Rubber Membrane)
Flexible, weather-resistant, and excellent for roof decks or large low-slope surfaces.
TPO (Thermoplastic)
Energy-efficient and heat-reflective — a smart option for modern flat roofs.
Flat Roofs Only Perform When Installed as a System
A flat roof is only as good as its prep and drainage. We approach every flat roofing project as a complete system — from substrate to scuppers.
What that includes:
- Precision slope design for water runoff
- High-performance insulation and vapor barriers
- Fully welded or torch-down seams for leak prevention
- Custom flashing around skylights, parapets, HVAC units, and more
Why Choose Us for Your Flat Roofing Project
Flat roofing isn’t a side service — it’s part of our core expertise. We’ve installed hundreds of low-slope systems for high-end homes, modern additions, commercial walkways, and historic restorations.
- Full System Installs & Replacements
- Skilled Crews for Torch-Down, Fully-Adhered & Mechanically Fastened Systems
- Drainage & Waterproofing Integrated into Every Design
- On-Site Supervision with Certified Roofing PMs
- Lifetime Workmanship Guarantee
Why Flat Roofing Is a Smart Investment for Midwest Homes
Built to Handle Snow, Rain & Ice Dams
Properly designed flat roofs handle water as efficiently as pitched systems — and we ensure every detail supports long-term drainage performance.
Clean Lines for Modern Homes
Flat roofing helps achieve that sleek, contemporary look — ideal for modern architecture, rooftop decks, and minimal elevations.
Low Profile, High Efficiency
Pair your flat roof with the right insulation package and you’ll enjoy energy savings and reduced heat gain — especially with TPO or reflective coatings.
Minimal Maintenance. Major Peace of Mind.
Flat roofs are easy to inspect and maintain, and when properly installed, can outperform traditional steep-slope systems in life span and reliability.
Built to Work with Skylights, Decks & Edge Metal
Our team designs every flat roof with the details in mind — including integration with railing systems, decking, edge trim, and more.
“Most Roofers Cut Corners on Flat Roofs. We Don’t.”
Flat roofing takes more than rolled membrane and a few screws — it requires planning, slope design, water control, and skilled installation. At Custom Installations, we build flat roofs that solve problems, not create them.
- Over 50 Years of Flat & Steep Slope Expertise
- Certified Crews and Site-Supervised Installs
- Trusted by Builders, Architects & High-End Homeowners
- Backed by Our Lifetime Workmanship Guarantee
About Custom Installations, Inc.
We’re a second-generation, family-operated company built on one core belief:
Craftsmanship matters. Always has, always will.
With deep roots in Chicagoland and Metro Milwaukee, our team has served homeowners, architects, and builders since 1969. From small repairs to historical restorations, we deliver consistent, high-quality results.
Hear From Homeowners Like You
Discover what real homeowners are saying about their experience with us. From start to finish, our team is committed to delivering quality, reliability, and results you can trust.
Greta Harrris
Carol Ann B.
Jonathan J.
Denali
Ryan Chitwood
Rob
Will Lynn
Jacob Rosenfeld
Robert Tschurtz
Brett Paschke
David Held
Jonathan Jonas
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What Homeowners Ask Us Most
How long does a flat roof typically last?
With proper installation and materials, flat roofs can last 20–30 years or more. We install systems designed for long-term performance, and we back full replacements with a lifetime workmanship guarantee.
What’s the best material for a flat roof?
It depends on your needs. TPO is a popular choice for its energy efficiency and seam strength, while modified bitumen offers great durability for smaller structures. We’ll recommend the right solution based on your property, usage, and budget.
Will a flat roof have drainage problems?
Not if it’s done right. Our installs include proper slope correction, tapered insulation, and custom drainage solutions (like internal drains, scuppers, or gutters) to ensure water flows off — not in.
Can you repair part of a flat roof or do I need full replacement?
We offer targeted repairs when the issue is localized and the rest of the system is sound. If the membrane is nearing the end of its life or has widespread damage, we’ll walk you through a replacement plan.
Do flat roofs need more maintenance than sloped roofs?
Not more — just different. We recommend periodic inspections to clear debris, check drainage, and reseal vulnerable areas. With this care, flat roofs stay reliable year after year.
Got More Questions?
Find Out If We Service Your Area
Custom Installations, Inc. proudly serves homeowners, builders, and property managers across Chicagoland, Metro and Milwaukee.
Primary Service Areas:
Illinois
937 Campus Drive, Mundelein, IL 60060
10936 N Port Washington Rd, Suite 343
Mequon, WI 53092
Give Us a call.
Want answers fast? Talk directly with our team — no call centers, no runaround. We’re here to help with quotes, questions, and urgent service needs.
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Prefer we reach out? No problem. Just share your info and we’ll give you a call — usually within the same business day.
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