CRL Tremco® 440 Aluminum-Backed 1/8 x 1/2 Butyl Sealant Tape

• Superior weather resistance for exterior glazing
• 100% solids, solvent-free butyl compound
• Available in Aluminum and Black colors

CRL Tremco® 440 Butyl Architectural Tape (SKU: 71017F1) is a pre-formed butyl sealant tape designed for glazing applications. The 100% solids compound of butyl and polyisobutylene contains no solvents or volatiles, preventing shrinkage and long-term sealant failure. Tremco® 440 forms a durable, watertight seal to prevent water infiltration and delivers superior weather resistance and permanent elasticity—even at low temperatures. Highly adhesive and adaptable, it is ideal for non-compression glazing of vision lites and spandrel panels in metal and wood frames in low-rise construction, and for lap sealing between steel, aluminum, porcelain and other similar or dissimilar panel materials.


Typical Properties:
Base Polymer: cross-linked butyl rubber (polyisobutylene); Solids Content: 100% by weight; Cure Time: fully cured before application; Hardness: 65 durometer Shore "00"; Temperature Range: Application 20°F (-7°C) to 120°F (49°C); Service -40°F (-40°C) to 158°F (70°C); Weathering: Unaffected by ultraviolet through glass. Remains flexible at low temperatures.

Limitations: Not for use in joints subjected to continuous water immersion or temperatures exceeding 158°F (70°C). Not for use with lites of glass over 75" (1.91 m). As lite size approaches this maximum, consider a higher-performance glazing system such as CRL Tremco® Pre-Shimmed Butyl Tape.

Applicable Standards: AAMA 800-92, 804.3, and 807.3.

Good Glazing Practices: Surfaces must be free of frost and standing water, brushed clean, solvent-washed (MEK, toluene or naphtha) and wiped dry prior to application. At installation, ensure positive contact and approximately 10% compression to fully mate joined surfaces. Glazing tapes held under compression with clips or wedges provide the best watertight seals.

Always use 80 durometer Shore "A" setting blocks at sill quarter points. Use spacing shims (50 durometer Shore "A") for lites over 100" to accommodate wind loading. Do not place tape below the sight line on the sill rabbet unless a cap bead is specified—in that case place tape 3/16" (4.76 mm) below the sight line to allow for the cap bead. Do not overlap tape ends; butt without stretching. Keep release paper in place until ready to set the glass to maintain a clean tape surface.

Product Warning:

Limitations: Not for use in joints subjected to continuous water immersion