Real Stucco Toronto vs. Synthetic Stucco GTA.

Many people are confused about the difference between real cement-based stucco and synthetic stucco. In the 1970s, we started hearing about stucco that didn’t crack and had more colour consistency than the stucco we were using. Then the word EIFS (Exterior Insulation Finish System) was thrown around, and the confusion started.

EIFS is for energy efficiency using foam boards or other products to achieve better insulation value, and is a whole different discussion. Much can be learned online regarding EIFS Systems. One of the problems is that we have so many names for synthetic stucco, such as Acrylic Stucco, Synthetic Stucco, Plaster Finish, and manufacturer names such as MX Acrylic, Dryvit, Sto, Synergy, Thoro, etc. Here is the difference:

Synthetic Stucco is made from acrylic resins and is very similar to paint. They have an aggregate added to replicate the look of stucco without some of the inherent problems of real cement stucco. Different sizes of sand are used to achieve different finishes, as traditional stucco uses various sizes of aggregates.

​Once on the wall, it would be difficult for anyone to tell the difference between Acrylic Stucco and a painted cement stucco wall. The key here is painted. It is pretty easy to tell the difference between real and synthetic, if not painted. Even though the products are supposed to be similar, when they are installed, they are worlds apart in physical makeup and functionality. 

Real Stucco uses natural materials and is cement and lime-based. Synthetic stucco is an acrylic resin-based product that uses no cement or lime. The similarity is the sand or aggregate used. The functional aspect is also essential. Synthetic stucco stops water from coming into the wall and is either characterized as waterproof or at least water-resistant.

Cement Stucco typically dries hard enough to keep water out, but the idea is not necessarily to keep water out of the stucco. More importantly, it can penetrate the stucco and then naturally wick out and dry by being highly vapour permeable. Synthetic Stucco can retain moisture if it can find a way in. This is usually through the windows, doors, or roof lines. Because of water-related issues, the manufacturers have tried to use co-polymer resins that have more vapour permeability than earlier synthetic stuccoes.

Cement Stucco is very rigid and is susceptible to cracking. This has been by far the number one problem associated with stucco.  Many variables cause cracks, all related to movement, and can be read about in earlier Blogs or online. Stucco also tends to dry differentially depending on how long the moisture stays on the wall. Cement Stucco typically is darker if it dries slowly and lighter if it dries quickly. In hot, dry, or windy conditions, the entire building can be lighter in colour than intended; conversely, in cloudy, moist, or wet conditions, the whole building can be darker than intended. In addition, walls can dry differently just based on shading.

The north side of the house can be drier than the south side. Even shading from the plank, trees, or other structures can reflect onto a wall and cause discoloration.   Synthetic Stucco was introduced to solve these problems, and for the most part, it did. Since Synthetic Stucco is similar to paint, it dries more evenly. Because of the nature of the resin, it moves more than cement stucco and is less prone to cracking. Keep in mind, I never said “solve or eliminate” the problems.

​Problems and their manifestation are all a result of degrees - how much movement, how much water intrusion. The other question was, of course, cost. A Price was always the motivation for using traditional cement stucco. It is relatively inexpensive. Synthetic Stucco changed that and made the cost significantly higher. Still, when stacked up against other claddings, both these materials are very affordable. So let’s go through and recap these products:

Synthetic Stucco Toronto

1.      Made of Copolymer Resin
2.      Uses sand or another aggregate to achieve the look of Cement Stucco
3.      Resistant to water
4.      Crack resistant
5.      Colorfast
6.      Comes  wet in pails
7.      Spread with an acrylic trowel
8.     More appropriate for dark colours
9.      Able to have smooth to weighty textures
10.    More expensive than cement stucco
11.     Can be used over a brown coat or in EIFS (Exterior Insulation Finish System)

Traditional Cement Stucco Toronto

1.       Made of Cement and Lime
2.       Uses different sizes of sand to achieve different finishes
3.       Highly vapour-permeable
4.       Comes dry in bags
5.       Spread with steel trowels and float
6.       More of a “natural look”
7.       Less expensive

As you can see, there are more differences than first meets the eye when making a decision which product to use. Cost is a factor, and how the materials function and ultimately look are certainly things that need to be addressed. Do your research, look at the budget, and make the right decision based on your design needs and expectations of all involved.