Where Engineering Meets the Elements
Precision-engineered, American-made thresholds and weatherproofing components, trusted since 1959.
THE ORIGINAL WEATHER STOPPERS
Since 1959, Combo Aluminum has been a leading manufacturer of exterior door components in the building and construction industry. Our experienced team of experts aim to provide our customers with high-quality products and a superior level of service.
Our Products
Every Combo Aluminum product is engineered for precision and durability. We manufacture thresholds, door sweeps, weatherstripping, and astragals designed to deliver reliable performance and long-term protection for your entryways.
DOOR BOTTOMS & SWEEPS
Door bottoms and sweeps are essential components for exterior doors, serving to create a tight seal between the door and the threshold. They help prevent drafts, water, dust, insects, and noise from entering the home, improving energy efficiency and indoor comfort.
COMBINATION SILL THRESHOLDS
A combination sill threshold for exterior entry doors serves as a dual purpose component, acting as a weather seal and a structural support for the door. The sill threshold also helps protect the door’s bottom edge from damage and wear, offering a smooth transition between the door and the flooring.
FABRICATION OPTIONS
Threshold fabrication offers various options to ensure a precise fit and functionality for different door systems. Sill notching involves cutting specific sections of the threshold to accommodate the door frame, creating a seamless connection with the sill for improved weather sealing.
SILL COVERS & ACCESSORIES
A sill cover for exterior entry doors serves as a protective layer over the door threshold, shielding it from the elements and wear. In addition, it enhances the aesthetic appearance of the entryway while extending the life of the door threshold by protecting it from direct wear and tear.
RESIDENTIAL THRESHOLDS
Made from durable materials like wood, metal, or composite, thresholds provide structural support to the door while preventing moisture damage and wear. Additionally, they offer a smooth transition between the door and the surrounding floor, enhancing both the functionality and appearance of the entryway.
INSULATED SILL THRESHOLDS
Insulated sill thresholds with substrates for exterior entry doors are designed to provide superior thermal performance and weather resistance. The integrated insulation helps reduce heat transfer, improving energy efficiency by preventing drafts and minimizing heat loss.
OUTSWING THRESHIOLDS
Outswing thresholds for exterior entry doors are designed specifically for doors that open outward, providing a secure seal and preventing water, drafts, and debris from entering the home.
COMMERCIAL ADA THRESHOLDS
Commercial ADA saddle thresholds for exterior entry doors are specifically designed to meet accessibility standards while providing a smooth, secure transition between the door and the floor. These thresholds feature a low-profile, beveled design that minimizes tripping hazards and allows for easy passage of wheelchairs, carts, and other mobility aids.
JAMB WEATHERSTRIP
Jamb-type weatherstrip for exterior entry doors is designed to seal the gaps around the doorframe, preventing drafts, moisture, and dust from entering the home. Installed along the vertical and horizontal edges of the door jamb, it creates a tight barrier that improves energy efficiency by reducing heat loss and enhancing indoor comfort.
ASTRAGALS & MEETING STILES
An astragal for exterior entry doors is a vertical strip installed along the meeting edge of double doors, typically on the inactive door, to enhance security and weatherproofing. Astragals are often equipped with a gasket or weatherstripping to improve insulation and energy efficiency further. In addition to their weather-sealing function, astragals also provide an added layer of security by preventing forced entry between the two doors, making them an essential feature for both comfort and protection.
REPLACEMENT SEAL INSERTS
Replacement seal inserts for exterior entry doors are designed to restore the weather proofing and insulation of worn or damaged door seals. These inserts fit into the grooves of doorframes or thresholds and are made from materials like rubber, foam, or pile effectively block drafts, moisture, and dirt from entering the home.
METAL MOULDING & FLOOR TRIM
Metal molding and trim for exterior entry doors provide both a decorative and functional role, enhancing the door’s appearance while offering protection against the elements. Made from durable materials like aluminum, metal trim helps safeguard the door frame from weather damage, wear, and corrosion.
New Releases
Advancing the Standard.
Discover the latest innovations from Combo Aluminum, featuring high-performance sills, weatherstrip, and aluminum components engineered for durability, precision installation, and cohesive design. Six decades of craftsmanship, refined for the future.
FULL LINE CATALOG
Access the full Combo Aluminum catalog to view our complete range of
aluminum exterior door products. Each item is presented with detailed
specifications, available finishes, and performance data—engineered for precision and reliability in every build.
Our Story
A Legacy of Precision Since 1959.
Established in El Cajon, California, Combo Aluminum traces its roots to Wally Miller’s patent of the original Combo Sill; an innovation that transformed the building industry.
Today, more than six decades later, our commitment to precision, integrity, and durability remains unchanged.
Every aluminum component we produce is engineered for performance, protection, and long term reliability.
Contact
Let’s Build Together.
Whether you’re requesting a quote, exploring distribution, or need technical support, our team is ready to help. Combo Aluminum is committed to fast response times, clear communication, and solutions built on trust and precision.