How to Make Stucco Cement

Stucco-finished walls, like these in Greece, are common everywhere.

Stucco, which is sometimes called "cement plaster," has almost entirely replaced lime and gypsum plaster as an exterior building finish. Cement stucco is cheap, hard, strong and fire-resistant. It is also breathable, so water does not get trapped inside walls. Stucco is usually sprayed on the exterior walls of new homes and applied with a trowel for repairs. Almost every mason has his own favorite formula for stucco, which often includes pigments. None of these stucco recipes differ very much.

Things You'll Need

• Wheelbarrow
• 47 pounds Portland cement
• 12.5 pounds Type S hydrated lime
• 5 cubic feet (about 33 gallons) of loose, damp sand
• Mortar hoe
• 4 oz. acrylic concrete bonding agent
• Water

Instructions

1. Pour 1/2 bag, 47 pounds, of Portland cement into a wheelbarrow. Stucco may be applied as a base coat, brown coat or finish coat. This finish-coat recipe produces a stucco that is harder and sets faster than base or brown coats.

2. Add 12.5 pounds of Type S hydrated lime and 5 cubic feet of loose, damp sand to the wheelbarrow. Five cubic feet is roughly the equivalent of six and a half 5-gallon buckets.

3. Mix all ingredients thoroughly with a mortar hoe. Mortar hoes have holes in the blade and shorter handles than garden hoes.

4. Pour 4 oz. of acrylic concrete bonding agent over the dry ingredients. Begin to add water a little at a time.

5. Mix the stucco with the hoe and add water until the stucco has the consistency of cake frosting. Depending on the weather, the stucco will remain usable for 30 to 90 minutes. The higher the humidity, the more time you will have.

References

• This Old House magazine; "Stucco Repair"; Thomas Baker
• "Stucco Recipes for the Mortar Sprayer"; Herb Nordmeyer
• "Stucco"; Portland Cement Association
• "Stucco"; Jack Cover; November 1988