subject: Installing Single Hung Windows In A Masonry Wall [print this page] Masonry walls present unique challenges to installing single hung windows. The first step is to establish the bottom edge. Mark the wall about an inch below where you want the sill, and then use a level and tape measure to set the other corner. Measure an opening half an inch wider than the window, to allow for adjustments, and then measure up to set the top edge. After that, drill the corners - use a masonry bit, and cut the opening with a saw fitted with a masonry blade. Be sure to wear goggles to protect your eyes.
Clean the sill and put flashing tape on it, two strips, one on the inside edge, and one on the outside. Cut the tape six inches too long, so that you can extend it up each side about three inches.
Place spacers on the sill and use shims to get them level, and then position the single hung windows in the opening. Use more shims and a level to achieve the proper degree of being plumb and level. Single hung windows have nailing fins. Drive galvanized nails into each of the prepared holes.
After that, cut flashing tape to cover the exterior. For the sides, tear the tape so that it is 4" too long, and then centre each piece so 2" go beyond the nailing fin on each side. Do the same at the top, but make the overhang 1" on each side.
Add insulation around the window frame, and then caulk sealant around the outside edge. If the window has any sort of trim, attach each piece. At this point, just fix and paint the drywall, and you're done.
