Mar Mac’s MacWrap is our flagship external joint seal for use on a variety of precast reinforced concrete structures to prevent infiltration and exfiltration at both vertical and horizontal connections and joint gaps. MacWrap has proven its ability to seal joints on storm-water retention systems, box culverts, junction boxes, septic and many other precast structures. MacWrap has successfully sealed thousands of precast systems across North America relying on 4 crucial components which work in conjunction to provide a superior sealing system in a single self-contained unit.

  1. MacWrap utilizes specially formulated aggressive rubberized mastic which once applied “cold flows” into the pours of concrete, bonding permanently with the structure wall and preventing any infiltration of foreign materials or contaminates into the precast system.
  2. MacWrap utilizes a minimum of two high tensile steel compression bands which permanently secure the coupler in optimal position before and after backfill. These securing bands also compress the mastic undersurface of the coupler into the structure wall, forming an instant seal against infiltration even before backfill. With the use of high strength tensioning ratchets to restrain, no extra tools, open flames, or additional priming agents are typically needed.
  3. MacWrap is unique in that the couplers are manufactured with an internalized bonded layer of woven polypropylene, greatly increasing puncture resistance and shear strength compared to some sealing bands extruded only from a mastic material.
  4. All MacWrap couplers are protected by laminated backing, typically a heavy duty layer of Polyethylene which is inert to acids, alkalines, and other potentially corrosive and dangerous pollutants commonly entrained in soil or groundwater. Mac Wrap can also be manufactured with alternative backings to resist high concentrations of hydrocarbons, PCBs, and to prevent degradation from long-term UV exposure for above ground applications.