Advanced Building Products, Inc.
P.O. Box 98
Springvale, Maine 04083
Tel: (207) 490-2306
Toll-free: (800) 252-2306
Fax: (207) 490-2998
E-mail: info@advancedflashing.com


BLOK-FLASH® C.M.U. Flashing System

The complete flashing system for single wythe C.M.U. construction.

Basic Use

BLOK-FLASH® is an embeddable flashing device for exterior single wythe C.M.U. wall systems. It collects moisture that infiltrates the wall and flows down the vertical cores and diverts it to the exterior. BLOK-FLASH® is useful at all flashing/weep hole locations including base of wall, above door and window openings, above bond beams, in parapet walls, basements and any other locations where flashing is necessary.

Technical Data

BLOK-FLASH® is a high-density polyethylene composition molded into a .0625 inch thick (1.59 mm) flashing pan with .3125 inch (7.94 mm) perimeter flanges. The .0625 inch (1.59 mm) concaved weep spout with a .20 inch (5.08 mm) x .64 inch (16.26 mm) opening and a 45° drip edge extends 1.0" (25.4 mm) from the outer flange. The inner and outer flanges are spaced to allow for 1.0" of mortar bond between the upper and lower course of C.M.U. in 8", 10”, or 12" wall systems. The weep spout ceiling extends 3.5" (88.9 mm) from the outer flange into the center of the pan and acts to suspend mortar, keeping the weep channel clear. BLOK-FLASH® is impervious to water and includes chemical stabilizers to protect against UV degradation.


Performance

Assessments of the performance of BLOK-FLASH® to handle moisture penetration and to develop bond capacity.

Testing Date: October 23, 1998
Test Performed By: Soil and Materials Engineers, Inc. 734-454-9900
Test Method: ASTM C-1389
Water Penetration of Masonry*

Water Penetration Using Blok-Flash®

Time/Hrs Base Exterior Base Interior Cores Below Blok-Flash Blok-Flash Weeps
4:30 None None None 3.775 Liters

*Used in conjunction with an integral water repellent system

Conclusion:

The sample wall absorbed minimal moisture (375 ml / 12 sq. ft.) at the exterior face (chamber side) with the penetrating free water collected by the BLOK-FLASH® system and weeped per design. No visual indications of water penetration or by-passing of the BLOK-FLASH® system were observed during the testing.

Testing Date: October 23, 1998
Test Performed By: Soil and Materials Engineers, Inc. 734-454-9900
Test Method: ASTM C-1072-94
Test for Flexural Bond

Flexural Bond Using Blok-Flash®
Flexural Strength Flashing System Exterior Face in Tension
BLOK-FLASH® 56.6 PSI
Through-Wall Membrane 5.4 PSI

Conclusion:

Testing indicated prisms constructed with the BLOK-FLASH® system provided 10 times greater bond at the exterior bed joint than the membrane through-wall flashing system.

Complete set of test results available upon request.

U.S. Patent Nos. 4,910,931, 5,870,864 and Patent Pending


Installation

  1. Lay the course(s) of block below the desired flashing level until above grade. Eliminate Step 1 if you lay BLOK-FLASH® on a formed concrete foundation above grade.
  2. Install the BLOK-FLASH® course by spacing two units on each block or evenly along a formed concrete foundation or slab. The drip edge on the BLOK-FLASH® weep spout should extend slightly beyond the exterior face of the block unit it is resting on.
  3. Span the continuous row of BLOK-FLASH® with BLOK-FLASH® bridge units. This will serve to divert descending water into adjoining BLOK-FLASH® units.
  4. If the walls are reinforced, simply eliminate the BLOK-FLASH® unit and adjoining bridges at the grouted core. Cross-bed the webs adjacent to the core to be grouted making sure to overlap the BLOK-FLASH® flange. This will prevent grout from spreading beyond the intended core.
  5. Utilize standard mortar spreading techniques with mortar lapped, first over the inner and second over the outer flanges of the BLOK-FLASH® units. This will stabilize the units during installation and later will help divert moisture into the BLOK-FLASH® units.
  6. Reduce clogging from mortar and grout droppings by installing a 2" to 3" layer of pea stone into the core cavity above the BLOK-FLASH® locations. This will suspend mortar droppings and/or loose fill insulation in the core allowing moisture to flow down the inside face of the block and into the BLOK-FLASH® . Loose fill insulation poured in lifts will prevent mortar and grout droppings from clogging the core cavities at all levels of the wall.
  7. Tool all head and bed joints and remove any obstruction from the weep spouts.

BLOK-FLASH® is one part of a drainage system that will perform best when used in conjunction with integral water repellent in the C.M.U. and mortar, reducing bridging and promoting the downward migration of moisture into the BLOK-FLASH® . Contact our nearest masonry supplier for information on integral water repellent systems.

This method of installation applies to both INSULATED and NON-INSULATED walls.








Standard Sizes

Model US-8 Model US-10 Model US-12
C.M.U. Type: 8" (7-5/8") 10" (9-5/8") 12" (11-5/8")
Height: .3125" (7.94 mm) .3125" (7.94 mm) .3125" (7.94 mm)
Width: 5.625" (142.88 mm) 7.625" (193.68 mm) 9.625" (244.48 mm)
Length: 6.75" (171.45 mm) 6.75" (171.45 mm) 6.75" (171.45 mm)

Units Per Carton (all models):

  • 100 w/Bridge

Short Form Specification

The through-wall flashing shall be the BLOK-FLASH® System as manufactured by Advanced Building Products, Inc. of Springvale, Maine. Telephone toll-free 1-800-252-2306.


Insulated and Non-Insulated single wythe exterior block walls shall incorporate:

BLOK-FLASH® embeddable flashing units. A high-density polyethylene composition molded into a .0625 inch thick (1.59 mm) flanged flashing pan with a concaved rectangular weep spout and a 45° drip edge.