Metal Roof & Metal Building Sealant Tapes

Self-expanding, universal closure tapes.

EMSEAL metal roof and building sealants are precompressed, self-adhering tape seals made from resilient, open-cell polyurethane foam impregnated with either a water-based acrylic-modified asphalt emulsion (AST Hi-Acrylic) or a water-based, acrylic impregnation (MST).

These sealants replace liquid-applied sealants, butyl tapes, and closed-cell closures in dynamic joint conditions.

EMSEAL tapes have been specified by metal roof and building component manufacturers and experienced erectors for more than 30 years.

How it Works

The foam is impregnated, precompressed, and supplied in continuous reels. At installation, it expands gradually, exerting continuous backpressure against the joint substrates. This pressure, combined with the adhesive properties of the impregnation, maintains a durable seal without mechanical fastening or wet application.

As building components expand and contract with temperature changes, the seal accommodates movement while maintaining continuous contact with the substrates.

Compression at installation is matched to the application: higher compression for watertightness in water runoff conditions; lower compression for applications such as snow seals at roof ridges.

Metal Roof & Metal Building Sealant Tapes

Self-expanding, universal closure tapes.

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Available in two impregnation options, AST Hi-Acrylic (acrylic-modified asphaltic) and MST (100% acrylic) are black and grey sealant tapes for metal roof and metal building applications.

EMSEAL precompressed foam expands to fill voids in roofs and wall construction.

Features

Will not dry out and become hard or brittle.

UV-stable and highly resistant to aging and vermin (bugs, rodents, birds, etc.)

Will not extrude from between joints when squeezed, which is a possibility with caulk or butyl-type tapes.

May be used in non-moving gasket-type applications as well as in moving expansion/contraction-type joints.

Sizes

Available compressed thicknesses:
3/32″ (2mm) up to 3/4″ (20mm)
Equivalent expanded thickness:
3/8″ (10mm) up to 3″ (75mm)

Available widths:
3/8″ (10mm) up to 5″ (125mm)

Download product size chart (pdf)

Movement

EMSEAL where movement is expected, and watertightness is required, the sealant tapes can accommodate +25% and -25% (total 50%) movement of the supplied compressed size when installed in gaps equal to the supplied size.

See compression chart below for levels of sealing at respective compression levels.

Color

AST Hi-Acrylic: Black
MST: Grey

Uses

Seal out dust, air, wind-driven snow, and moisture through joint details in metal buildings and similar structures, both pre-manufactured and site-built.

Ideal as joint fillers in expansion/compression seals in joints that are subject to movement from thermal expansion and contraction of a structure, and as gasket-type seals in mechanically fastened, non-moving applications such as lap seams.

Suitable for use against metal, plastic trim, and other materials common in metal building structures.

Use in all applications where the material will be allowed to expand to fill voids.

Provides a durable and versatile solution to these typically difficult-to-seal panel contours at eaves, hips, valleys, peaks, concealed gutters, etc.

Use small-sizes in flat-on-flat “gasket” applications (side laps, end laps, and laps with closures) where the material will be held at a high degree of compression by fasteners such as clips, screws, etc.

In gasketing applications, EMSEAL metal roof and building sealants are hard-working, long-lasting, high-performance alternatives to butyl-tapes which generally squeeze out; or to closed-cell materials which suffer compression set and additionally tend to dry out and crumble.

Sealing Levels & Compression

The following indicates levels of sealing at respective installed compression levels:

Emseal sealant tape compression and sealing level chart

The Choice: AST or MST?

AST Hi-Acrylic is by volume the most widely used. Black in color as the result of it’s advanced acrylic-modified asphaltic impregnation, AST affords economy without sacrificing performance.

MST features the latest in acrylic chemistry and is grey in color. Choice of MST over AST is really a preference of the user for color and chemistry.

Installation

Storage and Surface Preparation:
• Tape should be stored in a warm dry interior location. Ideal application temperature is approx. 75°F (24°C). Expansion will be faster at higher temperatures and slower at lower temperatures.
• IMPORTANT: Reels must be stored FLAT and kept compact. Should material expand in package it can still be used. Unroll material, allow it to expand, then recompress it between surfaces to be sealed.
• Tip: For faster expansion in cold conditions keep the material warm before use and, if desired, apply heat from a hair dryer to installed material to accelerate expansion. Joint faces should be dry and cleaned of dirt, oils, grease, etc. There should exist sufficient depth to receive full width of the sealant.
Opening Reels:
• Only open materials that will be used immediately. Remove shrink wrap.
• Cut in front of colored marking tape and pull back release liner to expose mounting adhesive.
Square Off Ends:
• Start and finish ends must be cut square. For easier cutting, spray knife or scissors with mist of water.
Peel Off Liner:
• Remove release liner to expose adhesive face of tape.
Adhere to Surface:
• Press adhesive face to one surface. Align other surface with tape. Secure surfaces together. Tip: if needed, cut and fit small filler pieces of tape to fill panel corrugation or voids.
Joining Lengths:
• Overlap one piece of tape to another. Cut through both pieces at a 45-degree angle with a long-bladed utility knife. Reposition mitered faces over each other and pinch them firmly together to make a join.

Available in many sizes. Consult EMSEAL or your product vendor if you have needs for varied sizes and uses. There are many sizes and configurations available for countless applications.

Availability and Price

Available for shipment internationally.
Prices are available directly from the manufacturer.
The product range is continually being updated, and accordingly EMSEAL® reserves the right to modify or withdraw any product without prior notice.

Limitations

• Will not adhere to components that are dirty or dust covered or to surfaces coated with oils or other release agents.
• Will expand to follow and fill irregular substrates within reason. Sharp corners and acute angles may need to be filled with additional filler pieces in order to ensure a proper seal.
• Substrate must be capable of resisting, without bending or deflection, approximately 1.5 to 2.5 lb/in2 (10 to 17 kPa) back pressure from the tape.

Sustainability

Environmental Product Declaration (EPD)

EMSEAL provides a third-party verified Environmental Product Declaration (EPD) covering its precompressed foam sealants and expansion joint systems (ASTM-EPD1130, valid March 2026 – March 2031).

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