Question 1

What is the difference between conventional stucco and one-coat stucco?

Accepted Answer

Conventional Stucco is the traditional stucco system. Conventional Stucco (or scratch & brown) consists of two-coats of portland cement plaster and one coat of finish coat over wire or metal lath. Scratch & brown coats are installed at 3/8" thick layers each, while the finish coat is typically installed at 1/8" thick.
 
The first coat is the scratch coat and called so because it is literally scratched with a tool, to leave long horizontal ridges that provide a mechanical key for the next coat. The brown coat (or second coat) brings the wall out to a level surface and usually to a full ¾" thickness. A finish coat is then applied over the brown coat. See more about Conventional Systems by visiting our Systems and Assemblies page.
  
A One-Coat System (Western 1-Kote, in our case) consists of a modified portland cement plaster coating that is designed to go on in a one coat layer from 3/8' to 1/2" in thickness, over wire or metal lath, with a finish coat typically installed at 1/8" thick.
 
One-coat systems are often applied over insulating foam. Some of these assemblies provide improved energy efficiency and higher R-Values when combined with an approved continuous insulation board component. W1K Systems are impact resistant, and may be installed as a conventional system coating (scratch & brown) coats complying with ASTM C926.
 
See more about Conventional Systems by visiting our Systems and Assemblies page.

Question 2

If One-Coat systems use insulating foam, how does Western 1-Kote differ from Exterior Insulating Finish Systems (EIFS)?"

Accepted Answer

There are some differences between the two systems, but both systems also share some similarities as well. Some of these are listed below:
Exterior Insulating finish Systems (EIFS) use lower density foam than One-Coat systems.
EIFS does not use metal reinforcing to hold the material in place, while One-Coat systems do. 
One-Coat system basecoats products are installed in thicker layers, and are portland cement based, while EIFS are not.
Traditionally, One-Coat systems are more durable and impact resistant than EIFS.
Both systems may be used in commercial and residential projects.
EIFS is substantially superior on R-Values and overall energy efficiency.
EIFS can contribute greatly towards LEED certifications than One-Coat systems.
One-Coat systems mey be finished with portland cement based and acrylic based products, while EIFS may be finished only with acrylic based products.
To see more about these systems, visit our Systems & Assemblies page.

Question 3

Is it normal for Stucco to crack?

Accepted Answer

To a certain degree, yes! Stucco naturally cracks. As mentioned in a Technical Bulletin issued by the Stucco Manufacturers Association: "There are two fundamental types of stresses that cause stucco cracks—internal and external. Internal stresses are due to the natural curing and drying process of stucco. Stucco shrinks as it hardens and gains strength. This shrinkage, when restrained, may create hairline cracks. External stresses are due to the transfer of outside forces into the stucco assembly. Common examples are at the corners of windows and doors. These stresses can cause movement within the stucco, which can result in wider cracks than internally generated cracks."

There are stucco systems assemblies in existence which may prevent the apperance of cracks in both the basecoat and finish. Ours is called Crack Resistance System or "CRS". 
 
This system is typically found in our multi-year warranty systems for both Conventional & One-Coat system assemblies. The system consists on a layer of BPS Kote with embedded fibermesh which is is designed to reduce surface cracking.
 
To see more about Crack Resistant Systems, visit our Systems & Assemblies page. For the full Technical Bulletin about cracking in stucco, click here.

Question 4

How to deal with Efflorescence in stucco and what causes it?

Accepted Answer

Let's identify it first. Efflorescence the crystalline deposit, usually white, that may develop on the surface of integrally colored exterior Portland cement plaster finishes. Typically, this manifestation occurs during periods of damp, wet and cold weather, but it can also occur during optimal weather conditions.

Efflorescence is not normally due to application or faulty materials. Rather, it is an unfortunate manifestation of a combination of various factors and events that sometimes take place together at the same time despite human efforts to contain/prevent it. As stated in a Technical Bulletin from the Stucco Manufacturers Association: "Once salt deposits have already manifested as efflorescence on the surface, a variety of methods have been suggested for effective removal. In general, most efflorescence can be removed by dry brushing followed by flushing with clean water. For the plastering industry, we oftentimes are dealing with efflorescence caused by Calcium Carbonate deposits. Calcium Carbonate efflorescence is a more serious problem compared with other types of efflorescence since it is extremely difficult to remove. It appears usually as a white “bloom” and, in worst cases, forms a hard white crust." For the complete SMA's Technical Bulletin regarding Efflorescence click here.

Question 5

Could any color be macthed for either Exterior Stucco Finish or Acrylic Finish applications?

Accepted Answer

Not really, but we could get really close! Although our Color Lab department does their best, there may be some instances in which some colors may be too dark or too bright to be replicated in Stucco or Acrylic finishes. Not every color can be replicated, but we can certainly give you close options. Contact the WBP Color Lab department near you to inquire about color matching.

Question 6

What's the difference between Exterior Stucco Finish and Premium Acrylic Finishes (PAF) ?

Accepted Answer

Exterior Stucco Finishes are portland cement based with lime and aggregates and may be mixed with color pigments added for color. It is available in a wide variety of textures and colors; although light and muted colors work better with this product, Exterior Stucco Finishes are traditionally used for adding depth and dimension to walls. It is the only product that combines the effects of texture, color and light. It is an excellent choice for southwest stucco designs due to the interaction of texture, color and light. it is not consistent in color like paint and can be unpredictable in terms of the finished 'color.' Exterior Stucco Finish is very poor at bridging cracks. So tolerance of hairline (or sometimes larger) cracks are required, especially in fine and super fine textured finishes.
 
Premium Acrylic Finishes are acrylic based products with high grade aggregates designed to express specific textures when applied to stucco surfaces. PAF is also available in a wide range of colors and textures from muted to saturated. The textures available with PAF look very much like Exterior Stucco Finishes but the product is far superior to exterior stucco at bridging hairline cracks. It is also water resistant and less prone to efflorescence. PAF offers a wider variety of color oprions and better fade resistance than Exterior Stucco Finishes.

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