Red Seal Glazier Practice Exam

Using an elastomeric sealant is a common method for sealing insulated glass units because it provides flexibility, durability, and an excellent seal against moisture and air infiltration. Elastomeric sealants can accommodate the thermal expansion and contraction that occurs in glass units due to temperature fluctuations, which helps maintain the integrity of the seal over time. This flexibility is crucial when dealing with insulated glass, as rigid materials may crack or break under stress.

In addition, elastomeric sealants typically have good adhesion to the materials used in insulated glass units, such as glass and metal frames. This property ensures a long-lasting, waterproof bond critical to the functionality of insulated glass. Given these benefits, elastomeric sealants are often preferred by glaziers for their effectiveness in maintaining the insulating properties of the glass while also allowing for the necessary movement between the materials.

In contrast, adhesive tape and mechanical fasteners do not provide the same level of durability or flexibility, making them less effective for sealing the edges of insulated glass. Silicone caulk, while useful in various applications, may not always offer the same performance characteristics as elastomeric sealants in terms of flexibility and long-term durability, which is vital in the context of insulated glass units.