4 5/16 Subframe Installation The subframe system is a great installation tool for installing windows in masonry conditions. Typically subframes are used in masonry openings so that windows can be anchored into the opening without having to anchor directly through the window itself. The subframe acts as a receiver to the window in which the subframe is anchored directly to the masonry. The window is installed into the subframe and is held into place with the use of compression trim clips.
Subframes are typically considered for openings that have a flat anchoring area on all four sides in which the subframe can be installed. Irregular openings or openings that require covering over existing window frames should consider our panning system. One of the great advantages of using the subframe system is that it makes installing a large window easier. The subframes four-piece track system is much lighter than the window and thus makes the installation process of squaring, leveling and plumbing the window much easier than doing this with a window weighing several hundred pounds.
Another advantage of using the subframe is that squaring, leveling and plumbing are made much easier, especially when multiple window units are used in each opening. The subframe can also be installed from inside the building. This can be a great advantage in multistory buildings where scaffolding or ladders would typically be needed. The procedures for installing the subframe are not complicated, but Gerkin recommends that a skilled installer who is familiar with commercial window installation be used for the installation.
Subframe systems are to be ordered by rough opening size only. When measuring the rough opening, look for the smallest rough opening size. Measure in at least three locations both in width and height. Typically the outer edges of the opening and the center of the opening are checked. Gerkin will downsize the subframe and the window so that there will be a 1/4 joint between the rough opening and the subframe on all four sides. The subframe will come factory cut to fit for your rough opening.
The subframe will need to be sealed then screwed together. Check to make sure that the joints are completely sealed with caulk prior to installation. Using a flat surface, lay the subframe sections down on the working surface and line up the predrilled holes on the jambs with the receiving screw grooves on the head of the sill.
Make sure that the sill is sloping to the outside. Use the provided subframe screws and screw in two screws per corner. Install commercial installation hard impact shims on the sill.
Shims should be placed at the ends of the head, sill and jambs and 16 on center then check for level. Then lift the subframe into the opening and center the subframe so that there is a 1/4 joint on all four sides. Plumb, level, and square into place.
When shimming make sure the head, sill and jambs are flat. Do not bow the frames when shimming. Check for twist by measuring the interior and exterior of the subframe at various points.
Place an anchor at each shim placement. Next, trim the shims to the correct size. Once the subframe is fully anchored into the rough opening, fill the exterior joint with backer rod prior to caulking.
Caulk the full perimeter of the subframe to the building with a high quality 100% silicone caulk. Using fiberglass insulation or soft cured foam insulation, insulate the interior 1/4 cavity around the perimeter of the subframe. Prior to installing the window into the subframe, caulk the anchor heads.
Then run bead of silicone on the inside legs of the sill on the window frame. Run a bead of silicone along the inside edge of the bulb weather stripping at the jambs and head. Lift the window into the opening by first setting the sill of the window onto the subframe sill.
Once connected to the sill, pivot the window forward into the jambs and head. Insulate the void between the window and subframe with batt insulation. Install two pre-cut subframe jamb clips. Place the barbed end of the clip into the subframe receiver groove. (Do NOT use caulk around the interior clips.)
Make sure that the bottom of the clip lines up with the bottom of the subframe sill. Using a block of wood (one-by-four) and a hammer set the block of wood on the clip and position the block of wood as close to the outside edge of the clip as possible. Using the hammer, pound the block of wood to snap the clip into place. Work your way up the clip until the whole clip is snapped into place. Repeat on the opposite jamb. The clip will not engage unless the edge of the clip takes the brunt of the force.
Hitting anywhere but the on the edge of the clip may damage the clip. Install the head clip. Place the barbed end of the clip into the subframe head receiver groove. Do NOT use caulk around the interior clips. Using a block of wood, (one-by-four) and a hammer set the block of wood on the clip and position the block of wood as close to the outside edge of the clip as possible.
Using the hammer, pound the block of wood to snap the clip into place. Work your way across the clip until the whole clip is snapped into place. The clip will not engage unless the edge of the clip takes the brunt of the force. Using 100% silicone caulk, seal the full inside perimeter of the subframe. By closely following these window installation procedures, your windows will perform at their best in operation and energy performance. Thank you for choosing Gerkin Rhino Series Aluminum Windows!