A base coat is a layer of cement applied to any structure before being overlaid with bricks.

In theory, it can be as thick as you want. In practice, though, there are two main types of cement base coats used in construction: Those that have been mixed with sand or stone scraps as filler. It's easier to apply yet costs more because of the filler. Pure cement consists of only cement and water (or oil). They spread easily and evenly but cost less than the ones above because they use less material. The base coat has two main purposes: The dried plaster acts as a seal to prevent water from seeping through the foundation. Also, the set plaster covers up the imperfections in the substrate that would otherwise be visible.

What is cornice cement?

Cornice cement (or cladding mortar) is simply an upgrade of the base coat. The difference between them is that base coats are meant to be applied on bare structures, while cornice cement is used specifically on brick facades. A cornice adhesive makes the facade more water-resistant and provides a smooth finish. It is also suitable for attaching cornices to plasterboard walls, ceilings, and sealing cornice joints. You can also use cornice cement for quick fixes of the cracks in windows and door frames. The downside? It's a bit more expensive, but it does have its benefits. A cornice adhesive is excellent for smaller jobs requiring quick fixes. It has high bond strength. Unlike base coats that have various extended working times, cornice cement has a shorter setting time. Cornice cement is either packaged in paper tubes or plastic buckets. In these instances, A cornice adhesive can be used as a standalone material, so no need to add sand brick scraps.

What is a cornice?

A cornice is a decoration that covers the top of an architectural structure. It can be as simple as plain brick or even be made of wood (timber) and stone. Its an important task for many builders.

Cornices are added so as to hide the junction between roofing and walls. The masonry walls extending from the roofline are for waterproofing purposes to prevent heavy rainfall from damaging your property's interior. A decorative cornice adds to the visual appeal of the finished edges.

A typical cornice consists of two parts:

The sofit is the part goes over the wall and creates a covered area underneath the roof where you could put electrical wires and plumbing fixtures.

The fascia is on top, and it does create a smooth transition between the walls and the roofing.

Can cornice cement be used as a base coat?

Yes, it can. It works especially well with modern masonry (particularly cement and concrete) because these materials tend to be incredibly sturdy and waterproof already due to their composition:

It is important that the surface of the masonry you want to apply the cornice cement on is clean from any dust or dirt before being coated. This way, you'll get a smooth transition between the two layers of material.

If you want to use this as a base coat, make sure it is thick enough. You'll typically need at least 9 mils (0.22 mm) of cement on the surface area in order for it to be considered as a base coat. It is recommended that you apply 2-3 layers of it so that it can adhere properly.

This process will take longer than using the cornice cement as a standalone material, but these structures can last for decades with proper care and maintenance if built by an expert builder.

What does a cornice include?

A cornice is typically composed of different parts: The moulding is also known as an entablature. This part will cover up the wall's surface. This goes with both types of cornice (metal and stone). The moulding will contain the part that is visible above the wall (the "fascia") and also the one below it (the "sofit"). The frieze is where you place decorative pieces for aesthetic reasons; The corbel can be either plain or carved with designs like flowers or animals. It projects outwards from the wall to support overhanging features like balconies, eaves, etc.

How do you use cornice cement?

Just like any other material in construction, cornice cement must be mixed before it can be applied to surfaces. If you do not follow the proper ratios when mixing it with sand, you may end up with a mixture that won't work. It will be difficult to apply and, in some cases, unusable.

How to apply cornice cement

There are different methods in applying a cement-based product. Some of which can be done by hand, while others need heavy machinery specifically designed for this purpose. The latter is recommended for bigger projects.

You'll see that separating the mixture from larger particles will give you better results. Likewise, if you have a power mixer, it would still do well to use your hands so as to get every single piece of material properly coated with the mixture.

For better adhesion, apply mesh or paper tape to cracks before applying the cornice cement. When filling a wall or plaster board cracks, set the mesh tape. Cover it completely with the adhesive. After the recommended drying time, scrape off high edges and use a fine grade sanding paper to light-sand the top coat until it's smooth. The process is the same when using paper tape to repair plasterboard wall cracks. Before using it to cover deep holes, ensure they are prepared correctly. Installing cast cornices is a skilled trained requiring a number of competencies, according to the training.gov.au website.

Can you paint over cornice cement?

Yes, you can. Many people do this because they believe that the more layers of paint it gets on top, the longer it will last. In reality, however, the opposite is true. The materials used for a cornice are different from those of a wall or ceiling, so it requires proper prep work before painting. This way, you'll be able to get a smooth transition between your painted surface and your cement-based cornice. Over time though, if your material starts to crack, whether due to rot or excessive moisture building up in some areas, then yes, you can definitely paint over it as long as you follow all safety precautions needed when painting chemically sensitive objects. It's best not to use solvents. They can lead to a chemical reaction with the composition of your cornice cement, leading to changes in its appearance or functionality.

Can you use cornice cement as an exterior finish?

Applying a cement-based material on external surfaces can be challenging because of their exposure to all kinds of environmental conditions, especially those exposed to direct sunlight for long periods. This includes areas like patios, terraces, and decks. When exposed to heat, it may crack, which is why proper care must be observed when tackling these types of projects.

What is the best way to install cornice cement?

Using something like wood or jute fibre for cornices with complex designs may work well for you. This will help keep things in place while the cement sets on areas hard to reach. They won't do anything to secure your entire structure, but they are handy when tacking specific portions of the cornice's surface. If not, then use some adhesive for this purpose.

Apply another layer over the cracks using cornice cement; Once everything has dried up nicely, cover everything with paint or perhaps even use sealant if needed. Its a task that can add great visual appeal to the overall look when building a house.

What is cornice cement grout?

Often, you'll notice that your material will look like it has some grout in between its crevices for added detail. You can achieve a similar effect by mixing cement with other materials to get this done. For example, if you want a darker colour shade, you can try adding black pieces of charcoal to the mixture, while lighter tones may need something more neutral coloured such as white sand instead. This way, whatever tool or object placed on top of your cornice's surface will have the same appearance from the bottom up, which eventually creates a uniform finish.