Hardcast Sealant Mastic 2INX 304099

The Hardcast 304099 is a two inch wide mastic sealing tape used for sealing duct joints and seams.

Mastic tape combines the sealing performance of a brushable mastic with the convenience of a tape. It carries a layer of mastic on a backing, so it is pressed onto the joint rather than brushed, and it seals as it is applied.

The distinction from ordinary duct tape is fundamental. General purpose cloth backed tape uses a pressure sensitive adhesive that dries out, loses adhesion, and releases, often within a few years and faster in a hot attic. Duct systems sealed with it are commonly found with the tape hanging off and every joint open.

Mastic based products do not fail that way, because the seal is formed by the mastic itself rather than by an adhesive holding a backing in place.

For this reason, codes and standards generally require listed materials for duct sealing, identified by a UL 181 or similar marking, and ordinary duct tape does not qualify despite its name.

Application requires a clean, dry surface, firm pressure to bed the mastic, and adequate overlap at the ends.

The tape form suits long seams and regular joints; brushable mastic remains better for irregular shapes and awkward transitions.

Confirm the product carries the required listing for the duct type and application.

Brand

Hardcast

SKU

304099

Category

Duct Sealants

Weight

3.1 lbs

Dimensions

9.00" x 9.00" x 2.00"

Price

$31.00

Availability

In stock (3 available)

Rating

0 / 5.0