Bituthene Mastic is a rubberized, asphalt-based mastic. It has excellent adhesion to structural concrete, masonry and wood. The VOC (Volatile Organic Compound) content is 225 g/L. Architectural and industrial maintenance regulations limit the VOC content in products classified as architectural coatings. Refer to Technical Letters for the most current list of allowable limits.
Bituthene Mastic is designed to seal terminations, edges of patches and overlaps in detail areas. On vertical applications, the mastic must be applied to both the top and bottom terminations.
Apply Mastic either with a caulking gun or trowel. If applied with a caulking gun, level the bead with a trowel to about 0.125 in. (3 mm) thickness and 0.5 in. (13 mm) to 1 in. (25 mm) width. When applied as a temporary cutoff, trowel Bituthene Mastic to 0.060 in. (1.5 mm) thickness. Bituthene waterproofing membrane may be placed over the thin cutoff the next day.
On the bottom edge of vertical applications, Bituthene Mastic should be troweled upward. Use it liberally at membrane terminations.
Material usage requirements for Mastic will vary widely from job to job. On large horizontal plaza areas with few protrusions, only about one quarter of a tube may be required per roll of membrane. A vertical application may require one half tube or more per roll of membrane. Applications involving other protrusions may require one or more tubes per roll.
Clean tools with mineral spirits at the end of each day. Mineral spirits is a combustible liquid and should be used only in accordance with the manufacturer’s safety recommendations. Do not use solvents to clean Do not use solvents to clean hands or skin.
Bituthene Mastic is an integral part of the Bituthene waterproofing system. This mastic should not be applied where it will be covered with Bituthene waterproofing membrane, except as permitted as a temporary cutoff. It should not be used as a primary waterproofing material.