Brief Anatomy of a Stucco Wall
Stucco walls consist of a base material which may be metal lath, brick, stone or concrete. A layer of stucco, which is actually another form of concrete, is then applied over the base material in layers until the desired thickness is reached. Some stucco walls are also painted, embedded with color pigments or textured. Though it is useful to know what kind of base material, paint, pigments and texture techniques were used in creating your damaged stucco wall, it is not necessary as the repair technique I am about to share with you will work for the majority of stucco walls.
Words of Warning about Stucco Repair
One caveat though, if your stucco walls are embedded with pigments instead of paint or textured with items like gravel, you will want to purchase replacement items that closely resemble the remaining wall. Otherwise the repaired area will stick out like a sore thumb. As far as pigments go, a good rule of thumb is to make a test batch first by adding a little bit of the metallic oxide pigments at a time to white stucco mix and then let it dry completely. Match the dried test batch to the remaining wall and adjust the color as needed before whipping up a full batch of pigmented stucco patch.
Materials Need to Repair Stucco Walls
In order to complete a minor stucco wall repair job you will need to gather together the following materials;
1 pair work gloves
1 pair safety goggles
1 putty knife
1 wire brush
1 pointed trowel
1 wooden float
1 bag stucco patch mix (make your own mix if need be)
Stucco pigments, if needed
Texturing materials, if needed
1 old blanket
1 roll duct tape, heavy duty
Access to a working garden hose
1 pair safety goggles
1 putty knife
1 wire brush
1 pointed trowel
1 wooden float
1 bag stucco patch mix (make your own mix if need be)
Stucco pigments, if needed
Texturing materials, if needed
1 old blanket
1 roll duct tape, heavy duty
Access to a working garden hose
Step 1: Clean and Prepare the Damaged Stucco Surface
Before attempting this task, be sure to don your work gloves and safety goggles. Once your safety gear is on, use the putty knife, pointed trowel, wire brush and garden hose to clean away any loose debris from the damaged area. Continue by wetting but not soaking a blanket with water. Duct tape the wet blanket over the damaged area and allow it to sit like that overnight. This is because the damaged surface area must be sufficiently damp to properly receive the stucco patch.
Step 2: Patching the Damaged Stucco Wall
According to the manufacturer's instructions, prepare the stucco patch mix. You may need to make your own stucco patch mix which should consist of one part Portland cement, three parts sand, 1/10 part hydrated lime and enough water to make the mixture a consistency of wood putty. Depending on whether or not the stucco base is exposed will determine what you do next. Damage that does not extend down to the stucco wall's base material may be patched in one application. However, if the stucco base is exposed, you will need to complete the patch in layers over at least two applications.
Assuming that the base was exposed, your first step will be to use a pointed trowel to firmly pack the damaged area within ¼ inch of the damaged area's surface rim. Once the damaged area has been packed with patch up to ¼ inches deep, wet the patch area and cover it with a damp blanket as described in step one. Allow the first layer of the patch to sit like that for approximately two days. In order to keep the blanket wet you may need to periodically sprinkle it with water. At the end of the two day period remove the wet blanket and, using a square trowel, apply another layer of patch mix so that the damaged stucco area is flush with the undamaged stucco area. Proceed by using a wooden float and any necessary texture materials to blend the repaired area in with the rest of the stucco wall.
Once the repair has been made you will need to recover it with the wet blanket and leave it like that while the patch cures. You will need to keep the blanket damp during the entire curing process, which generally takes three to four days depending on the brand of stucco patch used. After the patch has cured the blanket may be removed. Once the wall dries you may paint it if necessary.