Mortar Net Blok-Flash Flashing System

A Unique Embeddable Flashing System for Single-Wythe CMU Construction -Blok-Flash® delivers the surest, most cost-effective control of moisture and mold-growth in exterior single-wythe CMU wall systems. It provides 10 times greater bond at the exterior bed-joint than a membrane through-wall system, with no water penetration, no by-pass, and rapid expulsion of moisture (see test data).

Blok-Flash® is a tough, lightweight, embeddable flashing system, suitable for use at all flashing/weep vent locations, including base of wall, above door and window openings, above bond beams, in parapet walls, and wherever flashing is necessary.

When moisture infiltrates the wall and flows down the vertical cores, Blok-Flash® intercepts it and diverts it to the exterior, quickly and effectively.

Blok-Flash® HIGHLIGHTS
  • Useful in all 8", 10", and 12" exterior block applications.
  • A built-in "bridge" on each Blok-Flash® pan intercepts moisture falling between pans. Saves time over installing separate "bridge units"!
  • New polyester-mesh Drainage Matte inserts quickly into 2nd-course block-cells to capture mortar/grout droppings. No more need for pea gravel!
  • Sloped bottom of new Blok-Flash® pans make drainage even faster!
  • Saves more than half the labor and material associated with membrane flashing in a multi-wythe course.
  • Maintains stronger bond than through-wall membrane flashing (see test data).
  • Eliminates need for multiple sizes of architectural CMU (another cost and headache-saver).
  • Lightweight and compact, for easy shipping, handling and storage.
  • Reduces thermal bridging, helping to maintain the wall's R-Value integrity.
  • 40% recycled polypropylene can help buildings qualify for LEED certification.


Mortar Net® USA, Ltd.
326 Melton Road
Burns Harbor, IN 46304
Tel: 800-664-6638
Fax: 219-787-5088
Contact: info@mortarnet.com