Cabot Protec BlueGlass Sheathing was developed for commercial and residential application's where the product's performance will not be compromised due to extended exposure (up to twelve months) under normal weather conditions (as herein defined) during construction. "Normal weather conditions" shall mean climatic normal weather with usual high and low temperatures, with occasional moderate rain and wind. Abnormal weather shall mean severe wind and/or rain, hail, cascading rain, earthquakes, tornadoes, hurricanes, floods, and similar or like conditions. 

Cabot BlueGlass Sheathing is comprised of a proprietary formula which provides a fire-resistant and water resistant gypsum core, that has been reinforced with glass fibres to increase it's resilience. The product is encased in a mold-resistant coated fibreglass mat distinguishable by the blue colored fibreglass matt facer bearing the name Cabot BlueGlass Sheathing printing with the same blue colored back mat. The coated glass mats are dimensionally stable and resist warping, rippling, buckling and sagging due to fluctuations in temperature and/or humidity. These panels feature a square edge formation with the ends cut square.


Primary Uses

Cabot Protec BlueGlass Sheathing is designed for mechanical attachment to the framing using nails or screws. This product can be used as a substrate for exterior claddings such as wood siding, shingles, panel siding, vinyl or metal siding, masonry or brick veneer, conventional cement-stucco systems and Exterior Insulation and Finish Systems (EFIS). It is recommended that cladding be mechanically attached through the sheathing into the framing. 

Notwithstanding anything contained herein, exterior claddings and their application methods shall be the responsibility of the cladding manufacturer. Consult the local building code when a water-resistive barrier or vapour retarder is required. Cabot Protec BlueGlass Sheathing is suitable for prelim work prior to building enclosure resistance is required. This product is not designed to have joints taped or treated. 



  • Exposure: extended resistance to typical weather conditions not exceeding twelve (12) months after application.
  • Mold Resistant: mitigates mold and mildew growth.
  • Noncombustible gypsum board is naturally fire-resistive.
  • Dimensionally stable: resists warping, sagging, buckling.
  • Suitable for walls and exterior ceilings as well as prelim work prior to building enclosure. 



  • Is designed for mechanical attachment only to the wall framing using either nails or screws. Construction of fire-resistance rated design assemblies shall be in accordance with the construction details specified in the referenced fire-resistance rated design. Do not use as a nailing base. 
  • Is not a finished surface, but a substrate that shall be covered by exterior wall cladding and is not intended for joint treatment or paint. 
  • Is not a structural product, and not a replacement for structurally engineered sheathing requiring shear resistance. 
  • Shall be properly flashed at openings and located so that no joint will align with an edge of an opening. Joints shall be staggered. 
  • Holes and cutouts for pipes or fixtures, or other small openings, shall be properly protected by means such as flashing or caulking.
  • Check with local code for requirements for sealing horizontal joints. 


Storage and Handling

Store all Cabot Gypsum products flat; do not store on edge as panels are heavy and may fall over causing injury or death. Store in an area that offers protection from adverse weather conditions, condensation, and other forms of moisture. Avoid job site conditions that expose gypsum board to water or moisture. Plastic shipping bags are temporary, and intended for protection during transit only, and must be remove promptly upon arrival. Store gypsum board under protected cover, off the ground with sufficient support to prevent sagging. Exercise proper care to avoid impact, scuffing of the glass faces, undue flexing, and damage to board edges, corners and ends. 



Cabot Protec BlueGalss Sheathing shall be installed according to ASTM C 1280. 


Mold and Water Resistance

Cabot Protec BlueGlass Sheathing has been engineered with special chemistries that provide enhanced water and mold resistant protection in gypsum panel products. In independent laboratory tests per ASTM D3273 (Standard Test Method for Resistance Surface of Interior Coatings in an Environmental Chamber) Cabot Glass Sheathing products achieve a 10 rating, the highest level of performance for this test method. No material may be classed as mold-proof. Prolonged exposure can result in the growth of mold or mildew on any surface. The use of good design, with proper handling and construction practices, is the most effective and best method to minimize mild. This includes avoiding water exposure during all phases of the project, such as: storage, handling, shipping, and product installation and system maintenance both before and after project completion. 


Fire Resistance Rating

Fire Resistance Rated Designs are promulged from tests performed at IAS* certified independent testing laboratories, and these designs include specific materials assembled in precise configuration. When choosing construction details to achieve specific fire resistance rated requirements care must be taken to insure that each component of the specified assembly is the proper one specified in the referenced dire resistance rated design, and assembled in accordance with the specific requirements of the assembly. *(The International Accreditation Service-IAS- is a non-profit, public benefit corporation and a leading accreditation body in the United States. Internationally recognized, accreditation by IAS makes it easier to market products and services both inside and outside the United States.)


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