Serving Nassau & Suffolk County Homes with Premium Installations Since 1985
Long Island’s Experts in Windows, Doors,
Siding & Roofing
Thermo-Seal has been the go-to exterior remodeling contractor for homeowners throughout the Tri-State area for over 40 years. We specialize in high-quality windows, siding, roofing, doors, and gutters, delivering expert craftsmanship and top-tier products from industry-leading brands.
Unlike other exterior remodelers, we never use subcontractors—our full-time team ensures consistent quality and superior results. With elite-level certifications from leading manufacturers, such as Andersen Premier Certified Contractor, GAF Master Elite Contractor, and James Hardie ALLIANCE member designations, we bring the highest standards to every project.
WINDOWS
DOORS
SIDING
Roofing
Gutters
WINDOWS
Upgrade your home with high-performance Andersen windows, including composite Fibrex®, wood, fiberglass, and vinyl options. We also offer premium selections from Pella and Harvey, all backed by a limited lifetime warranty. Our expertly installed energy-efficient windows enhance curb appeal, improve insulation, and provide long-lasting durability with superior craftsmanship.
DOORS
We install Therma-Tru, Andersen, Pella, and Harvey doors, offering top-quality entry, sliding glass, French, and storm doors. Choose from wood, vinyl, fiberglass, or steel options, all of which deliver enhanced security, insulation, and style. Our expertly installed doors improve energy efficiency while elevating the beauty and functionality of your home’s entrance and living spaces.
SIDING
Enhance your home’s exterior with James Hardie fiber cement siding, known for its durability, weather resistance, and stunning appearance. We also proudly offer vinyl siding from CertainTeed and Westlake Royal Building Products, as well as cedar shake siding which will add a touch of natural warmth to your home. Available in multiple styles, our siding options provide superior protection and timeless beauty with minimal maintenance.
ROOFING
Protect your home with premium roofing solutions, including GAF asphalt shingles, tile, metal, and copper roofing. As a GAF Master Elite Contractor, we ensure expert installation and long-term durability. Our high-quality materials and professional craftsmanship offer superior weather resistance, energy efficiency, and a long-lasting, beautiful roof built to withstand the elements.
GUTTERS
Protect your home’s foundation with a seamless gutter system and gutter protection solution. Our high-performance gutters efficiently channel water away from your home, preventing costly water damage and erosion. Designed for durability and minimal maintenance, our systems keep your home safe while minimizing the need for gutter cleaning.
Certified. Trusted. Proven.
When you work with Thermo-Seal, you can expert craftsmanship backed by trusted credentials. We’ve partner with the industry’s leading manufacturers, earning their top certifications to bring you the best products on the market. As a fully licensed and insured company, we ensure your investment is protected at every step.
Why Choose Thermo-Seal?
For over 40 years, homeowners have trusted Thermo-Seal for superior exterior remodeling. We deliver expert craftsmanship, high-quality materials, and an unwavering commitment to customer satisfaction. With a proven reputation, professional in-house installers, and industry-leading warranties, we ensure every project is completed with precision, care, and lasting value.
Free, No-Hassle Estimates
We believe in transparency and convenience. Our free, no-obligation estimates give you a clear understanding of your project’s scope and cost—no pressure, no hidden fees, just honest advice.
In-House Installers
Unlike many contractors, we never use subcontractors. Our full-time installers ensure consistent craftsmanship, quality, and accountability, delivering superior results ever time.
Decades of Experience
Since 1985, we’ve been transforming homes across the Tri-State area. With more than 40 years of expertise, we provide top-quality remodeling solutions backed by a trusted reputation.
100% Satisfaction Guaranteed
Your happiness is our priority. We back every project with a 100% Customer Satisfaction Guarantee, ensuring you receive high-quality service and results that exceed expectations.
What Our Clients Are Saying
We strive to make the entire home remodeling experience positive for our customers—from your first phone call, until the final handshake.
“I had a very good experience with Thermo-Seal. Chose them after interviewing many others because they’re local, communicated efficiently, and offered good midrange pricing and lifetime warranty. The crew did a fantastic job with the installation. They came early and finished 5 windows in 5 hours, and then they cleaned up. Highly recommended!”
Patrick B.
“We just completed a window and siding job for our home with Thermo-Seal. We are very impressed and satisfied with the quality of their products as well as the installation. I would recommend this company & I would use them again in the future if needed.”
Mindy L.
“The crew was a pleasure to work with, and we love our new windows. The installation was efficient, and the team was very professional. I’ve seen a difference in my heating bill since the install, which was our primary goal so we are very happy so far! I will work with Thermo-Seal again for a front door replacement when the time comes.”
Bonnie K.
“We hired Thermo-Seal for new windows and siding and I could not be happier! Their team is on time, professional, and meticulous about their work. You can tell they take pride in their output and ensure things are done correctly the first time around. The project completed ahead of schedule and we were kept in the loop the entire time. Very happy with their work and highly recommended!”
Sarah C.
“We were referred to Thermo-Seal by a neighbor who was very pleased with the results. We replaced seven windows and a sliding patio door are thrilled with the results and how much they enhance the appearance of our home. Without hesitation, we recommend Thermo-Seal for your home improvement projects.”
Frank D.
“Cannot believe how stress-free an experience it was dealing with Aaron and his team. Aaron was very patient with our multiple questions and never any sales pressure. The installation was clean, quiet and the installation team friendly and helpful. The windows were installed a few weeks before they were promised and there were no surprises. We will be strongly recommending Thermo-Seal to friends looking for replacement windows.”
David B.
