Exterior Door Frame Sealant for Professional Installers

Exterior door installation is a high-movement application. The frame shifts. The substrate moves. The sealant has to stay sealed through all of it.

AU-1 Window & Door Sealant handles the differential movement between door frames and wall systems without adhesion loss on masonry, wood, vinyl, steel and fiber cement. No primer. Permanent flexibility.

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The Wrong Sealant on an Exterior Door Frame Costs You a Callback

Exterior door sealant failures show up fast usually as water infiltration at the sill or the head of the frame within the first winter. The cause is almost always a product that lacks the movement accommodation to handle the difference in thermal expansion between the door frame and the wall system.

AU-1 is formulated specifically for high-movement window and door applications. It won't pull away from the substrate as the frame expands and contracts.

AU-1 is rated to ±35% joint movement and 800% elongation — engineered specifically for the differential movement of window and door frame installations.

The Right Sealant for Exterior Door Installation

Use the correct sealant system to ensure long-term movement,
weatherproofing, and compliance on every install.

Recommended

AU-1 Window & Door Sealant

The primary sealant for exterior door frame joints designed for long-term flexibility and adhesion across common substrates.

ASTM C-920 Class 35

TCBSAT-30

±35% Movement

No Primer

Paintable

Lifetime Warranty

No failures

Built for movement, weather, and long-term performance.

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Tower AU-1 Window and Door sealant cartridge pair white and clear

Add-On

AU-1 Window & Door Sealant

Used for flashing integration around rough openings to create a continuous air and water barrier in commercial installs.

Liquid-applied flashing membrane

Seamless waterproof barrier

Compatible with AU-1 system

Flexible and crack-bridging

Seamless Protection

Creates a continuous air and water barrier around openings.

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WHY IT WORKS

Why Installers Choose AU-1 for Exterior Door Sealant

Spec-backed performance built for real site conditions.

01

No primer on any common substrate

Steel, aluminum, vinyl, wood, masonry, concrete, stucco, glass and fiber cement AU-1 bonds directly without a prime coat. Fewer materials on the job, faster installation, no waiting for primer to cure before you can gun the sealant.

02

AU-1 LAB integrates with door flashing systems

On where a weather-resistive barrier is required around the rough opening, AU-1 LAB provides a breathable waterproof membrane with no primer requirement and integrates with standard flashing tape systems.

03

Bonds to steel, aluminum, vinyl, wood, masonry and fiber cement

AU-1 Window & Door Sealant bonds directly to powder-coated and painted steel door frames without a primer. On bare metal surfaces, a test application is recommended.

04

±35% joint movement ASTM C-920 Class 35

Accommodates plus or minus 35% joint movement handles frame expansion and contraction. TCBSAT-30 rated no primer required on most substrates.

05

800% elongation stays bonded through thermal cycling

Permanently flexible will not crack or harden over time. Internally plasticised no plasticiser leaching over time.

06

Ships in 5 days in-stock at Gainesville, GA facility

In stock and shipping in 5 business days from Gainesville, Georgia. Find a distributor near you or order direct through the Tower Sealants store.

Frequently Asked Questions

Clear answers to the most common installation and product questions. Built for specifiers, installers, and commercial projects.

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Faster Installs. Fewer Callbacks.

Most installation failures come from poor adhesion or incorrect product choice. AU-1 eliminates both with primerless bonding and proven compliance to commercial standards.

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