drywall knife – 4-in.
Wire brush
Shovel
Wheelbarrow
Drywall hawk
Flat trowel
Rubber grout float
Pro Tip: Work safely around fresh stucco. According to This Old House Magazine, the alkalis in wet cement can cause burns. Wear gloves or touch the mix only with your tools, not your fingers. Keep a bucket of water nearby to wash any splashes off your skin.
In this video, This Old House general contractor Tom Silva explains how to patch stucco.
Steps:
1 Scrape loose, blistered stucco from the wall with a 4-inch drywall knife.
2 Clean away loose grit and dust from the wall with a wire brush.
3 Create stucco by mixing three parts sand, one part Portland cement and ¼ part lime in trough or wheelbarrow.
4 Add water and mix with shovel until stucco is the consistency of peanut butter.
5 Mix in some mortar dye to tint the stucco to the desired color.
6 Lightly mist the wall with a garden hose; keep wall damp while applying the stucco.
7 Place some stucco on the hawk, then spread it onto the wall with a trowel.
8 Patch in all exposed wall areas with stucco.
9 Use a wet rubber float to smooth and blend the new stucco with the surrounding surfaces.
10 Press the rubber float into the stucco, then pull straight out to create a stippled texture.
11 Allow the stucco to thoroughly dry, then apply a coat of masonry primer and paint.
Keep in mind that no patch, no matter how expertly textured, will perfectly match the color of the old stucco around it. As This Old House Magazine advises, to get a seamless look you may need to apply a pigmented coating over the entire surface — options include concrete paints and stains, mineral paints, lime washes, and “fog coats” of pigmented cement. Whichever coating you use, make sure it’s alkaline tolerant and permeable to water vapor. Otherwise, it will be peeling off in no time.
