Stucco Repair: Shadowing, The Most Important Concept
In order to understand stucco as a consumer, you must understand shadowing. If you don't know about shadowing then eighty percent of the rest of stucco problems won't make any sense. In a nutshell, even though most people think of stucco as flat, or almost flat it is in reality mountainous with hills, valleys, ridges, peaks, caves and overhangs. In many ways it's like viewing the Colorado mountains from an airplane flying high above. Looking straight down from a high altitude the mountains don't look very tall or appear to have much definition. As the plane gets lower and you look more towards the horizon (parallel) the mountains look taller and have more jagged features and detail. Looking at stucco is similar to this. And here's the kicker. When the sun shining almost parallel to the stucco wall and causing small bumps to cast long shadows, the variations from place to place on the stucco will look more uneven and less desirable.
A picture is worth a 1000 words.
Shadows minimized. Photo taken where the stucco grains cast short shadows. Notice the defect straight to the left from the upper left corner of the sign.
Same area of the stucco, different angle. Notice the splotchieness of the sand pattern. This is typical and normal. The grains of sand are casting longer shadows from this angle at this time of day. Ironically, this viewing angle has made the dent almost invisible. By stucco standards this wall was well done and unless you're looking at it critically from this angel it looks good most of the time. (We didn't paint this wall, this is at a gas station I use)
With the understanding that stucco looks different from different angles and always looks worse when viewed from an angle where shadows are long, everything else with regards to stucco patching and painting can now make sense.
Here is another example of a sanded stucco wall, with a harsh viewing angle used - which is maximizing the "shadowing". The particular paint (a premium acrylic) used makes the shadowing even more pronounced. More on that later.
Glad this isn't your home? The angle of the sunlight is making the worst shadowing possible. When the sun is in front of it, the defects are not quite as noticeable. (Yes, someone did a really poor job of patching the cracks on this stucco)
Exterior Patching & No Perfect Match
Its quickly apparent from searching on the internet that stucco repair is not written about very much. Even determining the types of stucco finishes available is difficult, and there is a reason for this. Tim Carter the famous newspaper columnist and contractor, wrote in one of his columns "Patching stucco so that you don't see the repaired area is as difficult as patching a hole in a piece of fabric using scrap from the original bolt of cloth. It is virtually impossible to do. A stucco mason can create an infinite amount of textures depending upon the materials used to create the stucco and the tools used to finish it. Blending the new texture with the original is a true art and craft. If you succeed in creating the illusion, go out and immediately purchase a lottery ticket!"
Though he conveys well the thought that patching stucco is difficult, for people with experience and patience a good looking (read not noticeable) stucco patch is possible in some situations.
In many other situations patches that can be seen but are not obvious to casual observers are also achievable. But unfortunately there are still situations where the correct answer is to live with the defects or re-stucco the entire exterior of the building.
The photo above is a typical example of what Mr. Carter was referring to. This is sharp sanded stucco with air voids and getting. Getting a perfect patch on just the center area is not realistic.
Here's a higher quality patch than the one pictured above it. There is a little shadowing but its not too bad.
Link to Next Page "Stucco Patching: Spoiler Alert"