EFCO Special Purpose Windows Installation - Manual (Page 45)

EFCO 2014 6
Window Installation Instructions - Typical Subframe Installation Section
Installa on of Subsill Drive‐in
 Field cut and install the subhead closure ght to the
opening condi on.
 Drive Alignment dart gasket between the window frame
and the interior leg of the subsill. The gasket is typically
EFCO part number WNA3 or WNA4. Leave a gap 2” or less
between the end of the drive in dart gasket and the
subjamb.
 Before apply the subjamb closures, seal over the dart and
fill the 2” or less void between the end of the dart and the
subjamb with silicone sealant. Join this seal to the seal
that is joining the subjamb and subsill. Tool sealant line
well, it will be visible on the end product. Visually inspect
the sealant to ensure the there are no pin holes.
 Alternate method: Some subsill applicaƟons use a drive in
wedge gasket such as EFCO part number WEB4 and WEB5.
This wedge gasket should be set in a conƟnuous bead of
silicone sealant. The area that will be underneath the
subjamb closure should be filled with sealant. The wedge
gasket should be cut to fit Ɵght between the subjamb
closures. Then driven into the bead of silicone sealant run
below it.
Drive‐in alignment
dart gasket
Seal over dart
(required)
Drive‐in wedge
gasket
Set wedge in a bed of
silicone sealant
(required)
This sealant will be
visible
Alternate Method
Preferred Method