What is the Difference between Stucco and Plaster?


    In residential construction we often see plaster and stucco as primary materials for some specific finishes. They look similar and may be used for the same purpose.

    Home owners that are not familiar with basics of construction do not know the difference between stucco and plaster.

    Today Remodel On Point once and for all breaks details about each material and all readers will understand how and which material is used.

    Main Differences between Stucco and Plaster

    • Materials They are Made of
    • Primary Use of Substance
    • Application and Installation Methods
    • Cost of Material and Installation
    • How Long They Last & Maintenance

    As you can see, these materials have fewer similarities than differences. Hopefully after reading this article you will be able to easily differentiate stucco from plaster material and understand basic principles of each material.

    Substances and Materials Stucco and Plaster Made of

    Our first main difference between these two substances falls down to components it’s made of. They look alike because most of substances are the same, but base is not.

    What is stucco and plaster made of

    Even though proportions of sand, lime, water and base material in stucco and plaster are different, we can see that 3 out of 4 components are the same.

    Gypsum is base of plaster. It is soft mineral made of calcium sulfate dehydrate. Gypsum base materials such as plaster are poured into molds or applied on surfaces with mix of water and sand. As it gets dryer and wormers, water evaporates and mineral starts to become hard.

    Stucco on other hand has Portland cement base. It does have drying qualities as well but maid hardening of material comes from curing process similar to concrete. Chemical reaction continues to solidify and make stucco into hard material.

    Use in Construction and Renovation Jobs

    Now we are going to take a look where stucco and plaster are used in renovation and construction industry.

    Stucco Used in : Exterior Siding, Interior Walls and Ceiling

    Plaster Used in : Exterior Siding, Interior Walls, Trims and Crowns

    Based on our findings they are both used in exterior and interior application as siding. This however is changing every year and plaster is less used for outside work.

    Inside of the house or building, plaster takes priority over stucco material. It is due to controlled environment of interior and how materials react to weather.

    Stucco doesn’t have any other purpose than to cover a wall for protection purposes and design looks, while plaster can be used for interior and exterior trims and even sculptures that are poured into molds and hardened.

    Application and Installation Methods

    Plaster has more options for installation and one of them matches methods for stucco.

    1. First layer is a scratch coat that creates protection for exterior surface and base for further material. Usually installed on wire mesh or hard surfaces.
    2. Second coat for stucco application is called brown. Ingredients are absolutely the same. It is done for smoothening out the surface area and filling all the gaps or deficiencies.
    3. Top layer is installed for decorative purposes as third coat. It can be different in texture, size and color.

    Application and installation is similar and to unfamiliar eye would even look the same. Plaster application is usually completed with two thicker layers or sometimes in one very thick layer. The idea is to solidify gypsum based product together as a cast.

    Difference in Cost of Installation for Stucco and Plaster

    Lest compare only apples to apples. We know that both stucco and plaster can be used for interior and exterior wall covering. Therefore we can use only this comparison for costs of installation.

    On average exterior of entire house installation of lath and plaster costs $6-$9 for labor and material. Prices vary from region to region and have no affect with type of application.

    Average cost of stucco installation for exterior of the house is $4 – $10 per square foot. Here is a big difference and it all depends on type of surface.

    Applying stucco directly on block or brick wall is easier than on plywood exterior of home, therefore cheaper. Colder cities assume layer of rigid foam insulation with stucco installation that drives up the cost.

    How Long do They Last & Maintenance

    Number five difference between plaster and stucco on our list is about lifespan and maintenance involved.

    Would you be surprised if we said that plaster can last longer than stucco on inside as well as outside walls? Apparently it’s true if we compare lath and plaster that was used in construction 50-80 years ago.

    Exterior plaster is not as good as interior, because moisture in the air and rain affects its durability. Asbestos and other particles were popular to add into plaster for increasing strength.

    Good stucco work can last up to 40-50 years, but home owners need to pay for touch ups and refinishing every 7-9 years.

    Lath and plaster exterior siding could last over 80 years, while these days its close to 40-50 years. That is because asbestos and similar dangerous substances were banned from construction industry.

    Maintenances for plaster is not expensive nor required every 10 years. Most of it is just painting on top.

    Similarities between Stucco and Plaster

    Each point that we discussed for differences has many similarities as well. So let’s go through each one and understand why people often confuse plaster with stucco and the other way around.

    Here is why people think stucco is plaster:

    1. Looks Similar to Inexperienced Eye
    2. Both Were Used for Exterior Siding
    3. Same Consistency before Application

    We should start with how it looks. If you don’t know all details, you won’t know if house build 30-50 years ago has stucco or plaster on it. Even if you walk up close and touch it with your hand.

    Coming to the second similarity point we discuss application for exterior of walls. If it looks similar and were used in construction for same purpose, how could regular home owners know the difference?

    When you first buy it in a bucket the consistency of material could not be more similar. Both stucco and plaster are mixed with sand, water and lime. The only difference is in initial base where plaster has gypsum and stucco uses cement.

    Which One is Better?

    Remodel On Point thought twice before trying to answer this question and we decided to base is on construction industry and opinion of home owners.

    There will always be people arguing that plaster is better and even more people taking side of stucco for exterior siding installation.

    Specifically for exterior of the house nowadays stucco is used way more. We are talking at least 95/5 ratio.

    Stucco material reacts less to weather conditions and continues to get stronger as concrete. It is also preferred because of the better looks.

    Is Stucco or Plasters Dangerous for Health?

    Technically speaking neither of them have substances that cause any harm to human body with severe consequences.

    However plaster and stucco sometimes associate with asbestos.

    First of all stucco never had any asbestos in it or any similar products. Cement base mixture is hard enough and does not require additional substances for insulation or strength.

    Exterior and interior plaster application have history of asbestos in it, if installed in specific era. During 1930s – 1970s asbestos was popular construction substance to add into insulation and plaster mixes.

    Nowadays products that are recently developed and installed are not dangerous to people.

    Steven H.
    Steven H.
    General Contractor and Home Builder with over 20 years of experience. Write and Edit educational posts for several Remodeling Blogs. Specialize in trade management and technical construction details.

    Same Category