Things You'll Need
Straightedge and T-square
Diamond glass cutter
Cutting glass to size, in order to replace a broken or cracked pane in a shower stall, is more conveniently done at a hardware or home improvement shop. It can be tricky, if you have little experience with glass, to achieve a clean cut and to keep a large pane from cracking when you cut it. If you decide to cut your own replacement shower glass, make sure you purchase the best quality diamond glass cutter you can afford.
Measure the pane of glass you are replacing. If possible, remove it from the shower frame and measure it lying flat to ensure that you get the most accurate measurements.
Spread an old bedsheet flat on a hard floor, such as the concrete floor of your basement. The sheet will cushion the glass and protect your floor from cuts, as well as collect any glass shards, should the glass break.
Put on work gloves and safety goggles.
Lay the glass pane onto the sheet.
Mark the needed measurements on the new pane of glass using a grease pencil. Use a straightedge and T-square to get a straight line for cutting.
Drip a small amount of oil onto the cutter wheel of a diamond glass cutter to lubricate it.
Cut along the cut lines on the pane of glass using the cutter, pressing hard enough to score the glass. It will not cut all the way through on one pass. Keep the cutter moving fluidly; do not pick up and press down on the cutter, if possible.
Hold the glass pane up, and snap cleanly along the scored line.
Repeat the process for all necessary cuts.
It can be helpful to purchase additional glass and practice your cutting and snapping technique.