EFCO S5500 Advanced User Manual
Page 27

EFCO CORPORATION 6/2012 PART NO. Y557
27
Series 5500 Advanced & Alternate Installation Instructions
Section V: Vertical Splice Joints
STEP #3 CRITICAL MULLION SEAL AT SPLICE
A. Insert the 1/4” x 1” x 5” long foam caulk joint backer as shown below leaving 1” of
the backer extending above the top of the mullion.
B. Apply sealant between the thermal struts, starting where the notch in the mullion
begins at the exterior cover, sealing the space to the top of the mullion as shown.
C. Tool the sealant flush with the face of the notch of the thermal struts.
1/4” X 1” X 5”
FOAM CAULK
JOINT BACKER
MULLION SPLICE SLEEVE
LOWER MULLION
SPLICE ATTACHMENT
SCREWS (cap seal)
Seal the gap between the
thermal struts including
the void at the bottom of
the notch.