Differences Between Stucco and Plaster

Plaster and stucco are among the most common building materials. They have similar properties and have a range of benefits. Both stucco and plaster are known for their superior durability and fire resistance. They are generally low-maintenance.

Despite these similarities, plaster and stucco are different building materials. If you cannot decide which material is best for your project, you have come to the right place. To help you make an informed decision, we take a look at some differences between plaster and stucco. 

Composition 
Stucco is a type of plaster, but plaster is not necessarily stucco. Exterior plaster is usually a mixture of lime, plaster of Paris, and water. On the other hand, stucco is a mixture of lime, sand, and Portland cement. The composition of plaster and stucco affect how they are applied and the areas in which they could be used. 

Versatility 
Plaster is more versatile than stucco. Stucco can only be applied to some types of surfaces, whereas plaster can be applied to smooth, even surfaces and rough, uneven surfaces. In addition, plaster can be molded to create custom designs. Stucco cannot be poured into molds.  

Installation 
Stucco and plaster should be installed by an expert with an in-depth understanding of these materials. Stucco is usually installed in three layers over a wire lath (similar to a wire mesh). The lath gives the stucco a surface to adhere to. 

The first coat is a scratch coat, the second is a brown coat, and the top coat gives the stucco its unique appearance. Exterior plaster can be applied the same way (in three layers). If you do not want to apply plaster in three layers, use gypsum veneer (it can be applied in a single coat). 

Application 
Plaster can be applied directly to interior and exterior surfaces, whereas stucco is exclusively meant for exterior use. In addition, stucco has a rougher texture than plaster and is more durable than many different types of plasters. 
That said, plaster can be applied to more types of surfaces. Before applying stucco, the surface should be prepared properly. Preparing a surface to apply plaster is usually a less-time consuming task. 

Can Stucco be Installed Over Plaster? 
Yes, if the surface was prepared properly, you can install stucco over plaster. 

Over time, plaster can accumulate dirt. Therefore, before applying stucco over plaster, clean the surface to remove dirt, dust, grime, and debris. 

If you don’t clean the surface properly, the stucco won’t adhere. After cleaning the surface, give it time to dry. Before applying stucco, make sure the surface is completely dry, moisture can get trapped in the wall, and your stucco could crack or chip in the future. 

Do-All Stucco & Stone is a leading stucco contractor in Calgary. We are your go-to team for stucco repair in Calgary. Our pros have years of experience installing and maintaining stucco. To learn more, call 403-588-5306. 

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