Decisions in the construction industry are often increasingly based on saving money rather than guaranteeing performance. When an insulation system is proposed for a project, it has been designed to meet the specific requirements necessary to perform in that particular environment. Changing parts of the system with products that have not been evaluated and recommended by the manufacturer can lead to underperforming insulation systems and severe consequences for personnel and infrastructural safety.

Although some accessory suppliers of lower cost products claim the same performance as the manufacturer-tested and approved accessories, there is often no credibility to those statements. There are major differences in the physical and chemical properties of all these products. These differences become apparent during testing and in-service performance after application. For this reason, we always recommend the adoption of a “total system” approach to specifying insulation and accessory products. The total systems approach is the only way to achieve the expected result of a high-quality, long-lasting insulation system.

Exterior coatings on insulation are usually reinforced with a fabric reinforcing mesh to improve durability, enhance mechanical resistance and help bridge insulation joints. Most fabrics sold for use with coatings are made from either cotton, glass or polyester. Cotton fabric can wick water and/or solvents, which can seriously compromise the integrity of the system and is therefore not a preferred fabric for use in conjunction with FOAMGLAS® insulation systems. Preferred alternatives are alkaline-resistant glass fabric and synthetic polyester fabrics that will not wick moisture.   Polyester fabrics provide high elongation that will accommodate the thermal and mechanical movements without rupture, allowing maximum movement of the coating. Both glass and polyester reinforcing fabrics have been tested and proven to offer superior performance with FOAMGLAS® insulation systems.

When selecting a fabric, attention needs to be paid to the size of the mesh. Larger openings will allow heavy mastics to penetrate the fabric to bond to the insulation. Reinforcing mesh with smaller openings can block the coating from passing through the fabric. This creates a barrier or slip surface and prevents the formation of the intended monolithic finish. Additionally, pinholes are much more likely to occur when a smaller mesh fabric is used.

Adhesives fall into two categories: One component (solvent or air cure products) or two component materials (products with two parts that require mixing before use). 

Generally, operating temperature and corrosion resistance will be the two strongest criteria in choosing an adhesive type. Silicones provide excellent heat resistance up to 260°C (500°F) for extended periods and up to 315°C (600°F) intermittently. 

Asphalt-based adhesives are recommended where corrosion resistance is a high priority due to possible contact with acids, alkalis and many chemicals. Other adhesive types include urethane, butyl rubber, polysulfide, epoxy, neoprene and styrene/polyester based products.

Utilized at joints, metal jacketing laps and around protrusions, sealants are used to prevent water vapor entry on low temperature, intermediate temperature, and cyclic systems. When used with the insulation, their function is to seal insulation joints and not to mask poor-fitting insulation. Butyl sealants are appropriate for use with FOAMGLAS® insulation because of their durability and low-temperature flexibility. Sealants must remain flexible and be resealable. They must also be compatible with coatings and resist mildew formation. 

For example, when our butyl-based PITTSEAL® sealants are tested against competitive sealants in a FOAMGLAS® insulation joint at 82 °C (180 °F), the PITTSEAL® sealant remained flexible, tacky, and did not crack or shrink.  In the same testing, some of the competitive products hardened, lost tack, cracked or shrunk after only two weeks. 
An approved MS polymer-based sealant alternative is also available to comply with the strict VOC regulations typically found in chilled water applications. This sealant offers the advantages of both silicone and polyurethane sealants in one product, without the disadvantages of either.

Although plastic jacketing has a relatively low perm rating, excellent chemical resistance and good impact resistance at normal temperatures, its ideal use is on indoor systems or under a metal jacket on above-ground outdoor installations that require additional weather or water resistance. For exterior applications, only ultraviolet (UV) -stabilized material such as coated PVC should be used.  Even then, the plastic jacketing life may be short on outdoor applications. Keep in mind that thermal expansion of plastic is high, and service temperatures are limited to a maximum of 65 °C (150 °F).

For most indoor systems, laminates are the preferred jacketing. On indoor applications using FOAMGLAS® insulation the primary function of a jacket is mechanical protection and aesthetics. A fully sealed FOAMGLAS® insulation system acts as its own vapor barrier. Therefore, laminate jacketings are considered a secondary vapor barrier when used over FOAMGLAS® insulation on refrigerated, chilled water, low-pressure steam and process lines.

In conclusion,  Owens Corning tested and approved accessories for use with FOAMGLAS® insulation should always be used as part of a FOAMGLAS® insulation system. 
There may be other products on the market that, depending on your specific requirement, can also meet your needs. 

However, it is imperative that the specifier and/or contractor check with Owens Corning to ensure compatibility of alternative accessory products. 

Using approved and tested FOAMGLAS® insulation accessories is one of the simplest and best ways for outstanding and high performance, while also minimizing liability for costly system failures.