EFCO Special Purpose Windows Installation - Manual (Page 50)

EFCO 2014 11
Window Installation Instructions - Typical Subframe Installation Section
Mullion Installa on Into Subframe
 Set mullion into the subframe and plumb to the opening.
 Fasten the mullion to the opening by using two mullion
anchor clips supplied by EFCO (KA20). Locate one at the
subhead and one at the subsill. Fasten the clip to the
mullion with the fasteners provided by EFCO, and to the
opening with fasteners provided by the erector.
 The mullion anchor at the sill should be set in a bed of
silicone sealant. Then seal over the heads of the fasteners
a aching it to the subsill and around the perimeter of the
clip. Tool sealant and inspect for pin holes.
 Lay a bead of sealant next to the gasket reglet on the
mullion. Join this sealant line to the back bead at the subsill.
Make sure this bead is taller than the bulb vinyl. (This bead
at the mullion can be leŌ out if and only if the mullion is
sealed to the window via an exterior filet seal, see page 12)
 Leave a gap 2” or less between the end of the drive in dart
gasket and the mullion stem.
 A er the window, subhead closure and subsill drive in dart
gasket have been installed, begin installing clips from the
top placing the 1st 1‐1/4” clip as close to the subhead
closure as possible. Then placing the rest 16” on center with
the EFCO supplied fasteners. Spacing may need to be reduce
depending on job condi ons (see approved shop drawings).
 Seal over drive in dart before installing the 4” pressure clip.
 There will be one 4” pressure clip for each mullion this goes
at the sill.
 A ach each mullion clip to both window jambs with the
EFCO supplied fasteners. Drilling into the window jambs is
not by EFCO. Ensure that the windows jambs remain square
and plumb.
KA20 mullion
anchor clip
Seal over
fastener
heads
Set mullion anchor clip
in a bed of sealant
Bead of sealant next
to gasket reglet
4” mullion clip
Fasteners to
a ach to mullion
Fasteners to a ach
to window jambs
Join sealant lines