Another alternative treatment we're considering for painting our bungalow's stucco exterior.
Even though painting our bungalow's exterior is off somewhere in the future (next summer???) we've continued to research alternatives for painting or tinting stucco. There are plenty of options out there, including lime washing and plain old latex paint. Now, thanks to Treehugger, we've added Keim Mineral Paints to the list.
Keim paint was invented in 1878 by Wilhelm Keim, who discovered a method to bond mineral compunds to inorganic surfaces like concrete or stone. Commonly used in Europe, Keim paint still isn't widely used in the US with applicaitons being largely limited to commercial uses and some historic preservation.
Keim paint is appealing to us for several reasons...
First, it has a wide range of applications. It bonds with any inorganic material and serves as a protective layer that, in the case of stucco, can minimize risk of cracking. It also can be applied as either a translucent or an opaque cover. This is appealing to us because we're still evaluating the right look for our bungalow. While I'm drawn to a tint that is translucent and preserves the natural variations of our stucco, we have some problems with staining so the opaque surface might be a good alternative if we can't deal with that some other way.
Second, Keim paint is highly resilient. Applications of Keim paint regularly last over 100 years with little degredation of color or protection. While our othe major option--lime wash--is also long lasting, it fades over time. The photo below shows how sulphuric acid impacts the two, respectively. Needless to say, both would outlast latex paint.
Finally, Keim paint is environmentally friendly. It's almost entirely made up of mineral extracts. The bonding agent is an engineered silica, but it has characteris similar to minerals as well as is environmentally neutral.
We haven't yet researched price at all, which would certainly be a factor. There aren't a lot of manufacturers in the States...we got a lot of our initial information from Keim Mineral Systems, which is probably where we'll start when it's time to start pricing out our alternatives.
So, while we're still unsure when we'll get around to actually doing anything it's good to have another option to consider.