Stucco 101: Watering The Final Color Coat

Stucco is a type of covering for homes or dwellings that has been used for centuries. It is a mixture of lime, cement, and sand, which can be applied over stone, brick, and wood, providing a seal from wind and other elements. Today, stucco is commonly used as an exterior for homes in hot and dry areas. The process of adding colour to stucco is simple but requires knowledge of the type of colour to add (powder or liquid) and how much to use. The colour is added to the finish coat and mixed with the base material before application. Powdered colours are typically used for cement-based materials, while liquid colours are added to acrylic and synthetic finishes. The drying time for stucco varies depending on the finish, temperature, and humidity, but it generally takes 24-72 hours for the true colour to show.

The finish coat is when colour is usually added to stucco

Adding colour to stucco is a straightforward process, but it requires some knowledge of the materials and procedure. The finish coat is when colour is usually added to stucco. The base material is typically a white or whitish-grey colour, and the finish colour is added to this base coat before being applied to the wall. The type of colour used depends on the type of stucco finish. Powdered colours are used for cement-based materials like traditional stucco finishes, while liquid colours are added to acrylic and synthetic finishes.

Traditional stucco finishes are made from Portland cement, lime, sand, and water. The colour is added to the finish material by first mixing it with a percentage of the total water required. This ensures that the colour is evenly distributed throughout the material. The base coat material is then added to the water and colour mixture, followed by the remaining water to achieve the desired consistency.

Acrylic and synthetic stucco finishes, on the other hand, are made with liquid acrylic and aggregates, such as crushed rock. To add colour to these finishes, the colour bottle is shaken and poured into the bucket of material. A small amount of water is added to the colour bottle to ensure all the colour is used. The mixture is then stirred according to the manufacturer's instructions.

It's important to note that colour consistency is crucial when mixing multiple batches of stucco. If possible, it's best to mix all the material at once to ensure uniform colour across the entire wall. If mixing in batches, it's essential to use the same method for each batch to maintain consistency.

The drying time for stucco can vary depending on the type of finish, outdoor temperature, humidity, and other factors. Acrylic finishes typically dry within 24-48 hours, while cement-based finishes can take up to 72 hours. Additionally, acrylic materials tend to darken slightly as they dry, while cement-based materials dry lighter than their freshly applied colour.

Powdered colour is used for cement-based stucco, and liquid colour is used for acrylic stucco

Stucco is commonly imagined in a grey and white colour, which is the natural colour of stucco. However, pigments can be added to the stucco base to achieve different colours. The two main types of stucco are traditional stucco (made with Portland cement) and acrylic/synthetic stucco finishes. The traditional stucco is mixed with dry ingredients and water and is grey/white when no pigments are added. Acrylic/synthetic stucco finishes come in a white liquid base form that is ready for colourants.

The two types of stucco require different colouring agents. Powdered colour is used for cement-based stucco, and liquid colour is used for acrylic stucco.

For traditional stucco, a powdered colourant is added to the stucco mixture before water is added. The amount of powder required depends on the total weight of the stucco base and the desired vibrancy of the colour. Manufacturers recommend using 3-7% of the total weight of the stucco base. The powder is first mixed with water, and then this coloured water is added to the stucco base. This process ensures an even colour throughout the stucco mix.

Acrylic/synthetic stucco, on the other hand, requires a liquid colourant. The liquid pigment is added directly to the stucco base and mixed with a drill. Acrylic stucco already comes in a bucket, making it convenient for adding and mixing the liquid colourant.

It is important to note that stucco colours can be customised, and there are as many stucco colours as there are paint colours. Adding pigments to the stucco base is preferable to painting the stucco after application, as it maintains the porous texture and breathability of the material.

The stucco colour will look different when dry

When choosing a stucco colour, it's important to know that it will look slightly different once it's dry. This is because the stucco mixture needs time to fully set and show its true colour. The drying time depends on factors such as the type of finish, the number of coats, outdoor temperature, and humidity.

Acrylic stucco finishes, which are primarily made of acrylic, usually take between 24 to 48 hours to dry and reveal their true colour. In most cases, they dry within 24 hours, but this can be extended to 48 hours if two coats are applied on cooler days (around 50-60 degrees Fahrenheit). Interestingly, acrylic finishes tend to darken slightly as they dry, so if the initial colour looks lighter than expected, don't worry—it will gradually darken.

On the other hand, cement-based stucco finishes can take a bit longer to dry due to their porous nature. They typically take between 24 to 72 hours to dry and display their true colour. The drying time is significantly influenced by the outdoor temperature and humidity as the material absorbs moisture from the air, slowing down the process. Unlike acrylic finishes, cement-based finishes tend to dry slightly lighter than their freshly applied colour.

It's worth noting that the "dry time" is different from the "cure time." Dry time refers to the initial setting of the material, giving it some strength and a colour that's close to the final one. Cure times, on the other hand, are extended periods where the material gains its full strength and final colour. Cure times can range from one week to a full month, depending on external factors, the material used, and other variables. However, in most cases, you don't need to wait for the stucco to cure to see the true colour.

To summarise, the stucco colour will indeed look different when it's completely dry due to the various factors mentioned. Therefore, if you're concerned about colour accuracy, it's advisable to test the colour on a small area or refer to the manufacturer's instructions for guidance on drying and curing times.

Colour coating offers long wear, but is more expensive than painting

Colour coating and painting stucco are two options for homeowners looking to change the colour of their exterior walls. Stucco is a durable and low-maintenance finish that can last between 60 and 80 years with proper maintenance. While painting is a more popular and cost-effective option, colour coating offers certain advantages that make it a more appealing choice for some.

Colour coating offers long wear, typically lasting 15 years or more, which is significantly longer than the average five years of paint. This makes it a more suitable option for those who are not interested in regular painting jobs. Additionally, colour coating can be applied soon after the stucco job is complete, usually within a few days, whereas new stucco must be allowed to cure for 28 days before painting. This means that the surfaces are not left exposed to the elements for an extended period.

The colour coating penetrates the entire layer of the exterior surface, unlike paint, which sits on the surface in a very thin layer. As a result, wear and tear are less likely to show on colour-coated surfaces. However, it is important to note that colour coating is more porous than paint, making it susceptible to water absorption, which can cause damage to the original stucco. This also makes it more prone to staining, requiring recoating to hide the stains.

Another consideration when choosing between painting and colour coating is the colour options available. Because there is a maximum ratio of pigment to coating in colour coating, darker colours may be difficult to achieve, limiting the colour options for homeowners. On the other hand, painting allows for a wider range of colours, as the paint is simply applied to the surface of the stucco.

In conclusion, while colour coating offers the advantage of long wear and less visible wear and tear, it is more expensive and may not be suitable for those seeking a wider range of colour options or concerned about water absorption and staining. Painting, on the other hand, provides protection against moisture absorption and is a lower-cost option that can be applied by homeowners themselves, but it may require more frequent touch-ups and involve more extensive preparation. The best choice will depend on factors such as the location of the house, weather patterns, and the condition of the existing surfaces.

Portland cement is used for colour-coated stucco

Portland cement is a key ingredient in colour-coated stucco. Stucco is a construction material used as a decorative coating for walls, ceilings, and exterior walls, and as a sculptural and artistic material in architecture. It is applied wet and hardens to a very dense solid.

The basic composition of stucco is cement, water, and sand. Traditional stucco is made of lime, sand, and water, while modern stucco is made of Portland cement, sand, and water. Portland cement was introduced in the latter part of the nineteenth century to improve the durability of stucco. It is very hard and brittle and can easily crack if the base it is applied to is not stable. Its typical colour is grey, but white Portland cement is also used.

Colour is added to the finish coat of stucco and mixed with the finish material before it is applied to the wall. Powdered colours are used for cement-based materials like traditional stucco finishes, and liquid colours are added to acrylic and synthetic finishes. The colour type depends on the base material, which is usually white or whitish-grey. For traditional stucco finishes, the powdered colour is added to a percentage of the overall water required for mixing to ensure the colour is adequately mixed into the material.

Colour coatings for stucco are formulated from Portland cement and colour pigments and are applied in a thin layer to the exterior of a home. While painting stucco is a lower-cost option, colour coatings offer long wear, typically lasting 15 years or more. They can be applied soon after the stucco job is complete, and the colour penetrates the entire layer. However, because the material is Portland cement-based, it is porous when dry and can absorb water, which can wreak havoc on the finish and potentially cause the stucco to peel off.

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