Old Mill Air + Water Barrier

5 gallon bucket

Old Mill Air + Water Barrier

5 gallon bucket

Total Area: 0 sq. ft.

In stock

Ships within 24 hours
Estimated Delivery Time: 4-7 Days

Product Features

The Old Mill Air + Water Barrier is a moisture barrier for external applications. The Barrier is applied directly to most common types of substrates and offers superior moisture resistance. The Old Mill proprietary blend will meet or exceed your expectations.



All Brickwebb products are protected by a 1-Year Limited Warranty.



All Brickwebb products are proudly made in the USA.



All Brickwebb materials are made from sustainable materials.



The Old Mill Air + Water Barrier is a moisture barrier for external applications. The Barrier is applied directly to most common types of substrates and offers superior moisture resistance. The Old Mill proprietary blend will meet or exceed your expectations.

Dry to the touch: 1 hour at room temperature

Recoat time: 2 hours at room temperature

Drying time: 12 hours at room temperature

Approved Substrates

Exterior gypsum sheathing (ASTM C1396)

Dens Glass Gold



Gold Bond e2xp








Exterior Plywood

Oriented Strand Board

Spray Application

Old Mill Air + Water Barrier is compatible with GRACO and Titan airless spray equipment with the following speicifcations:

Minimum 1 gallon per minute output.

Minimum hose width of 3/8 inch

Minimum tip size of 0.027-0.031

Minimum pressure requirement to spray of 2,000 psi at the gun with an airless sprayer rated no lower than 3,300 psi. Remove all filters in sprayer and gun before application.

Hopper Gun: 3/16" - 1/4" (6-6.5mm) orifice, 23-25 psi.



Job Conditions: Air and substrate temperature for application Old Mill Air + Water Barrier must be 40°F (5°C) or higher and must remain 40°F (5°C) or higher for a minimum of 24 hours. Provide temporary protection to protect the wall system from damage until permanent flashings, caps and sealants are installed. Store materials within prescribed temperature limits and out of direct sunlight. Working and drying times are based upon normal room temperature conditions will vary with temperature and humidity.

Preparation: The substrate must be clean, dry, structurally sound and free of efflorescense, oil, grease, form releast agents and curing compounds or anything that would affect bond. Painted surfaces are not acceptable and must be removed. Substrates must be flat and free of finds or planar irregularities greater than 1/4" in 10'0" (6.35 mm in 3.05m).

Concrete - Must have cured a minimum of 28 days prior to the application of Old Mill Air + Water Barrier. If form release agents or curing copunds exist on the surfact, they must be removed with a solution of muriatic acide or similar product (with appropriate precautions). Remove any residual acid by flushing with water.

Brick/Masonry - If joints are not struck flush, multiple coats may be required. Contact Old Mill for more information.

Sheathing Applications - Sheathing gaps must be less than 1/4" (6.4mm). For gaps larger than 1/4" (6.4mm) Old Mill Poly-Laminate may be used. Gap wood-based sheathing per manufacturers recommendations, typically 1/8" (3.2mm) minimum.

Mixing - Thoroughly stir Old Mill Air + Water Barrier into a homogenous consistency. Do no add water, over mix, or add accelerators or retarders to Old Mill Air + Water Barrier.

Application - Old Mill Air + Water Barrier is applied by first treating the joints and fastener locations where sheathing is used, then coating the entire surface using brush, roller, trowel, or airless spray equipment techniques. When using a foam roller, a maximum 3/4" (19mm) nap is recommended. Apply Old Mill Air + Water Barrier is an even, continuous coat, maintaining a wet edge of approximately 15 mils thickness. Oriented Strand Board and other porous substrates require two (2) coats of Old Mill Air + Water Barrir. For moisture protection, Old Mill Air + Water Barrir must be applied as a continous barrier of 10 mils dry thickness with no breaks or skips, although some areas will appear lighter than others due to the application process. The weather barrier applciation need not look like a painted surface.

Joint Treatment - Apply a thin layer of Old Mill Air + Water Barrier to the joints and embed Old Mill Poly-Laminate into the wet mixture and trowel smooth. Alternatively place and center Old Mill Poly-Laminate at all joints, corners, and gaps in the substrate. Immediately embed Old Mill Air + Water Barrier in the reinforcing mesh and spot fasteners using a paint brush or trowel and allow to dry.

Old Mill Air + Water Barrier may be flashed into window, door and other openings, using the same techniques for sheathing applications. Any remaining gaps should be filled with Old Mill Poly-Laminate.

Wall Treatment - Apply Old Mill Air + Water Barrier to the wall surface using the foam roller, trowel or by spray applying and backrolling to a uniform thickness of 15 mils wet, 10 mils dry with no pinholes or voids.

Clean Up - Tools and equipment can be cleaned with soapy water when Old Mill Air + Water Barrier is wet.

Limitations - Not for use as an exterior finish, note exposure limitations on front page.


Store in a dry place.

For thin bricks: BIA Care Instructions


Old Mill Brick products are covered for a period of one year from the date of purchase against any manufacturing defects and when used on a structure that conforms to local building codes and when installed in accordance with the manufacturer’s instructions.

Old Mill Brick will provide, free of charge, new materials to replace any determined to be defective. This warranty is limited to the original purchaser and may not be transferred to any subsequent owner.

This replacement warranty does not cover damage or deterioration resulting from:
Improper building practices or non-compliance with applicable building codes
Settling of the building or other wall movement or subsidence
Use of brick for below grade, sidewalks, paving for foot and vehicular traffic, mailboxes, soil dams or certain other limiting conditions
Collision, vandalism, war, civil unrest or other accidental or intentional events or other causes beyond manufacturer's control
Incorrect use of mortar or grouting methods
Contact with chemicals, paints or other coatings whether intended or untended
Discoloration due to airborne contaminants
Staining or oxidation.

This warranty covers only manufacturing defects in Old Mill Brick products.
Old Mill Brick, LLC. is not responsible for labor costs incurred in removal and replacement of defective products.


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