EFCO 406X Series - Manual (Page 12)

Series 406X Storefront Installation Instructions
EFCO 2014 Page 12
Section 3C. Expansion Mullions
Expansion mullions are required in elevations that are over 20’ - 25’ wide and can be used with both screw
spline and shear block systems.
 Do Not use expansion mullions at entrance jambs. Locate the expansion mullion at the next vertical mullion over so
that the distance between expansion mullions is never more than 25’-0”.
Screw Spline System Fabrication Steps:
1. Follow steps 1-3 in Section 3A for cut lengths and hole preparations.
2. Follow standard unit construction method.
Shear Block System Fabrication Steps:
1. Follow steps 1, 2, and 5 in Section 3B for cut lengths and hole preparations.
2. Follow standard unit construction.
W104
Note:
Expansion Joint gap must be
maintained before anchoring unit. W104
21U9 21V0
Fig. #10