The stucco begins with the lath. The lath is basically a combination of black paper and wire, these are installed over the plywood or yellowboard. Together, these items act as a water-barrier and a key for the stucco to adhere to the building.
Stucco consists of sand and cement and is applied over the lath in three coats known as the scratch coat, the brown coat and the finish coat. The scratch and brown coats can be hand applied or applied by machine or pump. The finish coat can be a cement based finish or an acrylic based finish. Each coat of stucco requires a proper cure time prior to the subsequent layer being applied, this will aid in ensuring the stability of the stucco and minimizes cracking.
By choosing from a variety of materials, finishes and colors, your stucco product can give your home or building a unique quality. The basic stucco finish is regular cement with a smooth to heavy texture. Color can be added to any of these finishes, however since this is a cementatious product, anything added to the cement can result in unavoidable cracks and color streaking. We like to advise that when using a color sand finish that painting may be necessary to achieve the desired end-result. The optional acrylic based stucco does not crack and maintains a true color. There is very little maintenance with this product and will last many years past a cement based stucco.
It is important to realize the limitations of the cement product you are choosing and research your choices accordingly.
As mentioned before, stucco is a cementatious product which means it is rigid and unforgiving to movement. With that in mind, as the earth moves, doors and windows close and walls receive force "cheddar cracking" may appear. Cheddar Cracking (as in the look of cheese) are small cracks, 1/8" or less and are perfectly normal, and standard within the stucco industry. They should not be filled with caulking or stucco, however sometimes painting the building after the stucco has completely cured, will minimize the appearance of these cracks.
Larger cracks in your stucco could be the result of a bigger problem and needs to be addressed with your builder or stucco contractor. These need to be repaired by a professional and again, should not be caulked.
After your stucco is complete, it is imperative that caution is taken when installing items such as lights, electrical boxes, canopies, etc. into the wall. If the waterproof paper (the lath) is penetrated in any way, water can, and most likely will leak inside and cause damage.
Like a puzzle, all items of the building process works together to complete a perfect picture. When windows aren't installed correctly, foundations aren't poured right, doors framed out of plumb, etc. this will affect the finished stucco product.
As stucco ages, it may get dirty which sometimes enhances the appearance of the finish. If cleaning is necessary, mild detergent, water and a brush will often times be all that is needed. If major cracking, over 1/8 th of a inch occurs, it is best to consult a contractor for repair.