If you have a traditional (cement based) finish on your stucco walls then chances are you have probably read about stucco fog coat somewhere and have a few other questions related to what stucco fog coat is, how it works and why you would need to use it.... Right?
This article covers a lot of those topics and helps answer that question. Stucco fog coating is really a simple and straightforward process and once you have the basics, you will have a pretty good understanding of what fog coat is and how it works.
What Is Stucco Fog Coating?
Fog coating is a coating that can be applied to a traditional stucco finish (cement based) that will even out the color of the stucco if variations of lighter colors occur, which is normal for traditional types of finishes.
It is a spray or brush applied product that uses powdered color pigments and cement (with no aggregate) and becomes an integral part of the stucco wall and will usually last several decades if applied correctly.
How Do I Apply A Fog Coat?
When you apply fog coat to a stucco wall you will more than likely spray it on using a pump type of sprayer, that you can find at just about any home improvement store or online at places like Amazon.com. You can also brush it on but is only recommended for smaller areas and if you have a lot of surface area to cover then I would definitely recommend spraying the fog coat on instead.
Since there is no aggregate in stucco fog coat, it can be sprayed which really makes it more of that paint type of product with out having to repaint every 3 to 7 years.
When you spray the fog coat on a stucco wall, it becomes part of the stucco itself and is not just sitting on top of the surface, it actually sinks in to the stucco surface and the stucco absorbs the color, making it work more like a stain would then a paint product.
Why Would I Need To Fog Coat My Stucco?
Fog coating stucco usually occurs at two different times in the construction process and is usually applied on existing buildings that need the color to be freshened up due to fading or staining. A fog coat will help rejuvenate the exterior of the building and bring it back to it's original color by spraying on a new fresh color coat.
The other point in time when fog coats are necessary is right after the finish coat is applied and there is some color variation due to various reasons. Variation in color for cement based stucco finishes is normal and anything from too much water on a float, moisture in the air (humidity), fast or slow drying times and many other factors can contribute to and I'm even color variation in the finish.
Some people like the variation in the traditional stucco finish and some people don't like it as much, so fog coating will even out the variations and make the walls a solid color. Fog coating is applied much faster than the finished out and since it can be sprayed on is really easy to get a consistent color on the entire surface.
Fog Coat Colors Are Something To Look Into:
Color Charts - There are specific colors that you can choose from and every stucco manufacturer has a little bit different color variation, so you will want to check out different manufacturers unless you know the specific brand of stucco that is used on your house, then you can just get a matching fog coat color to match your existing color as close as possible.
I put together a post that shows many of the most popular stucco manufacturers fog coat color charts, in a single location which helps you compare the different variations a lot easier and I recommend you check it out, if interested.
Custom Colors - It is important to note that you can actually get custom colors made from most stucco manufacturers and they can match most colors, if you bring in a sample. Remember though, fog coat colors are neutral and "earthy" type of tones so you need to be sure that the color sample you provide is close to that hue and not something to vivid or too bright.
Be sure to get a color sample before you actually order any fog coat material if you are getting a custom color match to see how close they can get the color to match. This is very important because making custom fog coat colors is not like paint and there are limitations to it.
Always test a spot before applying a large amount of fog coat on the wall. Make sure it is somewhere that will an area that will not be seen (or seen often) to see how the color turns out.
Are There Any Drawbacks To Fog Coating Stucco?
There are not a whole lot of drawbacks when it comes to font coding stucco but a couple that come to mind would be the fact that fog coating can change the color of your stucco surface but you will usually only be able to achieve a similar color or something slightly darker in color.
Color Limitations - It is possible to change the color of your stucco using a fog coat but it is intended to even out color variations in traditional stucco finishes and is not really intended to completely change the color so if you do want to use stucco fog coat to change the color of your stucco, I would recommend that you try out a sample spot to see how it turns out before proceeding with the entire building.
Color Choices - Since fog coat material is also a cement-based product, the color options you will have will be very limited in the sense that you will only typically find neutral and earthy type of tones when looking at difference stucco fog coat color charts. You will not be able to achieve bright and vibrant colors like you would if you were picking out paint colors.
Limited Applications - Fog coating will only work on a traditional type of stucco finish that is cement-based. Stucco fog coat is a cement-based product and requires the stucco surface suck up the color that is sprayed on the wall, and a cement based finish will do that because it is porous and absorbs moisture. So it will not work on painted surfaces or any type of acrylic finish.
This really limits you to only being able to use a stucco fog coat on walls that have a traditional stucco finish.
What Types Of Stucco Finishes Can Accept A Fog Coat?
Like I stated earlier, only a stucco wall that has a traditional type of stucco finish that is cement-based is able to accept a fog coating. The existing stucco needs to be able to suck up the fog coat material and since cement-based products tend to be porous and absorb moisture, they are perfect for accepting fog coats.
Painted surfaces will not be able to accept any type of fog coating and the paint will either have to be removed or you will have to apply a recoat on the entire building. If you want to recover the entire building then I would just recommend adding color to the finished material and only fog coat if there are color variations after you are finished applying the finish coat to the entire building.
If your stucco gets darker when you take a water hose to it, then chances are you have the right kind of finish. When the wall gets wet, it turns a significantly darker shade of the dry color version of itself.