Things You'll Need
Metal nibbler (optional)
Air compressor (optional)
Hand saw or circular saw
16 penny nails
Metal siding fasteners
Corrugated metal siding may be durable and for the most part maintenance free, but when it comes time to installing a window in your building, the procedure is a bit different than when installing a window in a building with conventional siding. The high and low spots -- or ridges -- along the length of the siding give the metal strength, but the edges of a conventional window will not sit flush against the siding. Windows are available that make installing one in corrugated siding easier and give professional-looking results.
Measure and mark the window's rough opening dimensions onto the corrugated siding in the desired mounting location. Leave at least 2 inches of metal around the entire perimeter of the opening if the location is close to the edge of a wall, roof line, door or other window. Get the rough opening dimensions from the instructions that came with the window.
Cut through the corrugated siding on the marks made for the window rough opening. Use tin snips or a metal nibbler powered by compressed air. Remove the siding from the cut-out area.
Cut through any studs protruding through the opening with a reciprocating saw around the perimeter of the rough opening. Add pieces of lumber to build up the perimeter of the rough opening with wood equal to the thickness and depth of the building framing members. This makes a sturdy mounting area for the window. Use 16 penny nails to secure the pieces to the original building framing members.
Raise the window to the opening with the top facing upward and the bottom held slightly away from the building. Raise up the window only slightly, so the lip of the J-trim on the top of the window slides under the steel siding at the top of the rough opening.
Rotate the bottom of the window inward. The bottom J-molding should sit flush to the metal siding at the bottom of the rough opening.
Secure the window to the building by driving in screws or nails that have a rubber washer -- whichever type of fastener recommended by the siding manufacturer -- through the edges of the siding around the rough opening. Go through the nailing fin on the window, which is the extension that attaches the window, and into the wood frame members of the rough opening.
Apply silicone sealant from a caulking gun to all four corners of the window where the J-trim meets the corrugated siding to prevent future water leaks.
Drive metal siding fasteners in until the rubber washer compresses slightly against the surface of the siding. Driving the fasteners in too far can bow the siding inward, as well as compressing and deforming the rubber gasket, which can cause water leaks.