How to Cut a Window in a Stucco Wall
To remove stucco successfully, you should understand that it consists of Portland cement plaster (stucco), metal lath and a protective membrane. The metal lath or, in older homes, chicken wire, provides support for the stucco as the installer applies the wet material to the vertical surface. Without that support, the stucco would slide down the wall before it dried. Taking care when you remove the stucco will mean less repair and patching as you finish the wall around the new window, making the overall job much easier.
Measure the new opening and mark your cut lines with the chalk line so you have a guide.
Drill holes at the four corners of the square opening you've drawn on the wall.
Score along the lines with the chisel and hammer to make a neat break in the stucco.
Use a power saw fitted with a masonry blade to cut into the stucco to a depth of about ¾ inch. This should also cut into the metal lath used to support the stucco. You can make a series of shallow cuts until the blade hits the metal lath and you see sparks.
Chisel or hammer the plaster away from the wall so that you reveal the metal lath and building paper or weather resistant membrane beneath. Use the pry bar if it helps to grab and pull the stucco toward you.
Cut the sheathing on the house after you've finished removing the stucco to finish the opening. Remember there will be studs behind this and you should address the drywall or plaster walls from inside the house.
Things You Will Need
- Measuring tape
- Chalk line
- Pry bar
- Masonry blades wear quickly and you will need to readjust the depth of the power saw to ensure a consistent cut depth.
- Lay a tarp below your work area to catch pieces of stucco and make cleanup easier.
- You can cut a grid pattern into the wall so that you remove large areas of the stucco rather than one big piece.
- Wear safety glasses, a respirator and protective clothing to protect yourself from the dust you'll produce as you remove the old stucco.
- Make sure you've cut the metal lath before you pull it away from the wall or you may pull more stucco from the house than you want to remove.