749 Vapor-Blok™ Water Based Vapor Barrier


749 Vapor-Blok™ Water Based Vapor Barrier2018-10-02T20:13:11+00:00

749 Vapor-Blok™ is a premium quality water-based vapor-barrier coating which effectively prevents water vapor from passing through it. It is designed to prevent the passage of water vapor into thermal insulation on cold systems or surfaces colder than ambient temperature. It is compatible with virtually all types of thermal insulation including Foamglas and can also be applied to a variety of other types of substrates as needed. It is a safe, easy-toapply water-based latex emulsion, but it achieves the type of low perm rating normally associated with solventbased products.

749 Vapor-Blok™ has a smooth, creamy consistency most suitable for application by brush (it can also be sprayed with the proper spray equipment). For applications where a heavy build is desired, a heavybrush/trowel grade is available (method of application should be specified when ordering). It has a pure white color, which remains white in service and matches most white jacketings and facings. It is excellent for protecting the insulation on cold air ducts, chilled water lines, cold storage equipment, and other similar cold systems.

749 Vapor-Blok™ is a very low-odor, low VOC coating when compared to other coatings of this type, and thus it is preferable to workers on the job site and also when being applied in inhabited spaces. It achieves its low perm rating at only 30 mils dry film (30 sq ft/gal), therefore jobs can be completed using less material than with competitive products.

749 Vapor-Blok™ is very effective vapor-barrier coating and should not be used where a breathing coating is required. Always make sure insulation being coated is dry.

749 Vapor-Blok™ meets the 25/50 flame and smoke requirements of NFPA 90A, and complies with MIL-C19565C, Type II, and is QPL listed.

749 Vapor-Blok™ MUST BE PROTECTED FROM FREEZING IN SHIPMENT AND STORAGE. After application it must be protected from freezing and moisture until thoroughly cured.

Note: 749 Vapor-Blok™ may be used outdoors but after exposure to ultra-violet light the white color will dull slightly to an off-white. It should not be applied to a flat horizontal surface where it will be subjected to standing water.

Vimasco manufactures under a stringent quality-assurance program in accordance with MIL-I-45208. Our manufacturing and Quality Assurance procedures are routinely audited by government and private industry inspectors.

Product Information and Data


In accordance with OSHA Standard 29 CFR 1910.12 (Right to Know Law) a Material Safety Data Sheet is available for the product and all Vimasco products.


Vimasco products are designed to meet the needs of specific situations. They are warranted to be effective for their intended uses only. No further warranties are expressed or implied. The methods and condition of application over which we can exercise no control are important factors in the performance of our products. We make specific recommendations for the application and use of all Vimasco products, but we cannot enforce our recommendations upon users; therefore, it is necessary that we state, as a condition of sale of our products, tat we will replace or refund the purchase price of any Vimasco product found by our laboratories to be defective, but that we assume no responsibility beyond the purchase price of the materials. No representative of our Company, Distributor or Agent has any authority to change or extend this condition of sale.