A well-built window is only as good as the way it is set into the wall. The ALPES C113 is an outward-opening system window built around a 6060-T66 aluminium profile with a 1.8 to 2.0 mm wall, a PA66GF25 multi-chamber thermal break, and a fully glue-injected corner structure that makes the frame a single rigid unit. Those same features that give the C113 its strength and weather tightness also change how it should be installed. If you are new to the format, a quick primer on what is a casement window helps before reading the steps. This guide walks through a correct C113 installation, from opening prep to final hardware adjustment, so the triple sealing, the equal-pressure line, and the CMECH operator all perform as designed.
| Feature | C113 specification |
|---|---|
| Profile grade | 6060-T66 aluminium |
| Wall thickness | 1.8 to 2.0 mm |
| Frame width | 113 mm |
| Glass sash thickness | 57 mm |
| Mullion width | 75 / 21 mm |
| Thermal break | PA66GF25 multi-chamber |
| Hardware | CMECH, German Red Dot, 30,000-cycle tested |
| Screen | Sash-mounted Black HD Anti-PM2.5 mesh |
| Opening | Outward (outswing) |
Before opening the carton, lay out the following items: measuring tape, a four-foot level, shims (plastic shims are preferred), low-expanding foam, butyl or window flashing tape, exterior-grade silicone caulk, a drill with the correct bit, screws sized to the wall substrate, a utility knife, and safety gear. Keep the C113 unit flat and protected until it goes in. Its glued corners are rigid, not flexible, so the frame should never be levered or twisted into place.
Measure the rough opening at three points for both width and height and record the smallest figure. Check that the opening is square by comparing the two diagonal measurements; if they differ beyond the tolerance in your project specification, square it up first. The C113 frame is 113 mm wide with a 57 mm glass sash and a mullion of 75/21 mm, so leave enough reveal for the frame depth plus insulation and trim. Inspect the surrounding wall and subsill for rot, moisture, or movement and repair before proceeding. If you are carrying out a casement window replacement, remove the old sash and hardware, cut the old sealant, and check the rough opening is still sound before moving on.
An outward-opening sash sheds rain on the outside, which makes the rough-opening weather barrier the most important part of the job. Apply self-adhesive flashing tape to the subsill, then up each side by at least 150 mm, lapping the tape so water is directed outward. Add a sill pan or backer rod where the drawings specify one. Because the C113 uses a glass centerline, a thermal-break strip, and an equal-pressure sealing strip that are meant to sit on the same axis, any water that bypasses the barrier will reach those channels. Do not rush this step.
Set the C113 into the opening without fasteners. Stand back and confirm it is centered with even reveals on all sides. Run the level across the head and the jambs. The frame's 8 mm-thick 6060-T66 profile resists bowing, but the triple sealing defense, which blocks wind, rain, noise, and extreme temperatures, only works if the frame stays true. Over-shimming or forcing the unit will distort the sealing line and the multi-chamber insulation. Adjust with shims at the corners and at the lock and mullion points.
Fasten through the frame's designated fixing points, starting at the top corners, then the bottom corners, then the intermediate points. Snug each screw; do not over-tighten. Over-driven screws are the most common cause of a warped casement frame and a sash that will not pull tight. For masonry or concrete subsills use the appropriate anchors; for timber framing use screws long enough to reach solid structure. Keep the frame plumb and level as you go, and re-check with the level after every two fixings.
Once the frame is fixed and operates square, fill the gap between the frame and the rough opening with low-expanding foam. Never use high-expansion foam, which can bow the 1.8 to 2.0 mm profile. Trim the excess, then complete the flashing on the head and sides, lapping over the sill tape. Finish with a continuous bead of exterior-grade silicone around the perimeter, both outside and inside where visible. This is where the C113 monolithic sealing pays off: because the glass centerline, the thermal break, and the equal-pressure strip are aligned on one axis, a continuous outside barrier keeps the whole chamber system dry.
Reattach the operable sash to its hinges and fit the CMECH operator. CMECH hardware carries a German Red Dot Design Award and is tested to 30,000 open-close cycles, so the moving parts are built to last, but they still need correct adjustment. Swing the sash open and closed, then lock it; the sash should meet the frame evenly with no gaps and no binding. If it drags, adjust the hinge or jamb screws rather than forcing the handle. The fold-away handle should sit flush when closed.
The C113 ships with a sash-mounted Black High-Definition Anti-PM2.5 mesh. Mount it to the sash so it sits flush and can be removed for cleaning. Because the screen is part of the sash assembly rather than a clip-on retrofit, keep the sash sealing surfaces clean during installation so the frame, the sash, and the mesh all seal as one.
Install interior and exterior trim, caulking every joint. Then run a full operation test: open, lock, and unlock several times; confirm the triple sealing defense engages with a firm, even pull; check that the screen seats correctly. A correctly installed C113 should move smoothly, lock without effort, and show no daylight through the closed seal.
Outswing aluminium system windows reward precision. If the opening is out of square, the wall build-up is unusual, or the project is a large villa or commercial facade, work with a qualified casement window contractor and confirm fixing schedules and tolerances with ALPES. Many manufacturer warranties and performance claims depend on installation matching the engineering drawings, so document the as-built details.
Choosing the right product is half the job; setting it correctly is the other half. Review the full C113 specification and related system windows, or talk to the ALPES team about project support and sample units before your next opening is cut.
