Looking at all of the different stucco products out there nowadays it can be a little bit confusing to know one product from another and how many different types of stucco there really are, which one is best and so on.
It really is not that confusing if you have a general overall idea of the stucco process in general.
This article outlines some of the basic systems involved and will really help to explain some of the different types of stucco systems out there, the different types of stucco finishes that you can choose from and will even touch on some of the different materials used in the stucco process to give you a better idea of what to expect.
The Different Stucco Systems That Are Used:
There are two main types of stucco systems that are used and these are hard coat systems and EIFS systems which can look very similar when finished but are in fact, very different.
Hard Coat Stucco Systems - These are cement based stucco systems, which are why they are referred to as "hard coat" systems and have a base coat of cement that is applied before the finish coat is applied (in most cases).
These can range in depth, depending on a few different factors like which stucco system you are using (three coat or one coat/two coat system), what substrate you are going over, etc. The general thickness for base coats can be from 3/8" - 7/8" typically.
The base coat is usually comprised of cement (typically Portland cement), sand and water and gets extremely hard, if properly cured. This is referred to as the base coat that will make a suitable foundation for the finish coat to be applied. The base coat is also where the "hard coat" stucco system gets it's name.
3 Coat Stucco "Hard Coat "System: A typical three coat stucco system will consist of a water resistive barrier (asphalt infused paper typically), wire, a scratch and brown coat (hard base coats) and a finish coat (with a primer coat applied if necessary).
The image on the right from Omega stucco shows a typical three coat system and the two grey colored materials are the base coats which are the "hard coats" in the system.
1 Coat Stucco "Hard Coat "System: A one coat stucco system (also known as a two coat system) also uses a cement base coat but is only 3/8" thick, instead of 7/8" thick like three coat system.
It is a lot like the three coat system but usually has a foam that is used and no scratch coat is applied, only a brown coat. The picture on the right shows a typical system and the grey material is the "hard coat" part of the system, made up of a cement based material.
EIFS Stucco Systems - An EIFS system is actually an acronym for Exterior Insulation and Finish System and does not rely on a hard base coat but instead is thinner layers of modified materials that make up the EIFS cladding.
EIFS is usually a little different and is known to have better water barriers and insulation properties than traditional hard coat stucco systems and most EIFS assemblies are designed to keep water on the outside of the building, whereas a hard coat stucco system will absorb water and it will leave the system through evaporation and/or through the weep screed.
The best example would be to look at some of the most common EIFS claddings out there to get a better idea of how they work. Different manufacturers have their own special systems but the "basics" are essentially the same, having little differences between the many systems.
Basic EIFS Assembly: The picture on the right illustrates a basic EIFS system that is an Omega Stucco system and uses an adhesive on the substrate, foam insulation board, a base coat that is embedded with mesh and a finish coat.
The main difference between this system and a hard coat system is the adhesive base used to adhere the foam to the substrate and a different finish coat that is designed to keep out water.
An EIFS Assembly With Added Water Management System: EIFS claddings can have specialty layers within the assembly that serve a specific purpose and the two most common layers help to keep out moisture and air and are usually referred to as moisture barriers and air barriers.
The picture on the right illustrates an EIFS cladding that uses a water barrier on the substrate (red layer) before the adhesive is applied.
The Types Of Stucco Finish Materials That Are Available...
There are also different types of finishes that are available as well and these can have their own advantages and disadvantages withing their own right and can also have different appearances which can make your exterior stucco look a specific way (when compared to the other type of finish materials).
Cement Based Finishes - Cement based finishes are made from a white Portland cement instead of a dark gray Portland cement that is typically used on the base coats of a hard coat stucco system. The base is white so that you can add color to the material in order to get an even, integrated color in the finish coat.
These are typically around an 1/8" thick, depending on what type of finish you are going after but can be as thin as a 1/16" if you are going for a smoother type of finish.
Acrylic Finishes - Acrylic finishes are made of acrylic that have an aggregate added to them in order to achieve a desired look. The best way to think of an acrylic finish would be to visualize a really high-quality exterior grade paint with some type of aggregate added to it but the material itself will be much thicker and stickier than paint would be.
An acrylic finish will typically be on the center side, hovering somewhere around 1/16" for most types of finishes.
Synthetic Finishes - Synthetic finishes are a lot like acrylic finishes and are even made up of acrylic, in most cases just like acrylic finishes are. Synthetic finishes are typically used more in EIFS systems and are designed to keep water from entering the wall so they do have a little bit different characteristics to them in a standard acrylic finish would.
Aggregate sizes can also affect the overall look and feel of a stucco wall and will be very different in appearance when the finish coat is finally applied. Nearly every type of stucco finish material will have "aggregate size choices" that you can choose from and these are typically referred to as smooth, fine, medium and coarse.
What About The Different Finishes/Textures?
There are different textures/finishes available that are available and some of the more popular stucco finishes/textures can be found here. Each type of finish material is capable of achieving a desired look or many different types of textures if applied correctly but will have different appearances, depending on what type of finish material you are using.
For example, a sand finish stucco texture can be achieved using any type of finish material but a cement based finish that uses a coarse aggregate will look a bit different than an acrylic or synthetic finish that uses a coarse aggregate because of the different material makeup but will be the same finish.