Panels are attached to parallel studs through the expansion joint flanges, enabling the finished surface to contract or expand naturally without cracking. #40 is ideal for joining dissimilar wall types such as CMU to wood framing and at construction joints. If installed horizontally, assure the female portion is on top.
The adjustable expansion opening, or reveal, is 1/4" to 5/8". Additional weather shields should be installed behind the joint to enhance the weather resistance of this system. Backer-rod and elastic sealant is often installed to assure water resistance.
The #40 Expansion Joint is also available in zinc for increased corrosion resistance.