Thursday, June 7, 2012

Real Stucco vs. Synthetic Stucco

Many people are confused by what the difference is between real cement based stucco and synthetic stucco. In the 1970’s we started hearing about stucco that didn’t crack and had more color consistency than the stucco we were using. Then the word EIFS (Exterior Insulation Finish System) was thrown around and the confusion really started. EIFS is for energy efficiency using foam boards or other products to achieve better insulation values and is a whole other discussion. Much can be learned on line 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 size sands are used to achieve different finishes as traditional stucco uses different size 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 fairly 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 make up and functionality. Real Stucco uses natural materials and is cement and lime based. Synthetic stucco is acrylic resin based using no cement or lime. The similarity is the sand or aggregate used. The functional aspect is also important. Synthetic stucco stops water from coming into the wall and are either characterized as water proof or at least water resistant. Cement Stucco typically dries hard enough to keep water out but the idea is not to necessarily keep water out of the stucco. More importantly it can penetrate the stucco and then naturally wick out and dry by being highly vapor permeable. Synthetic Stucco can keep and hold 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 vapor 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.  Cracks are caused by many variables all related to movement and can be read about in earlier Blogs or on line. Stucco also tends to dry differentially by how long the moisture stays in 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 color than intended; conversely in cloudy, moist, or wet conditions the entire building can be darker than intended. In addition, walls can dry differently just based on shading. The north side of the house can dry darker than the south side. Even shading from plank, trees, or other structures can telegraph on to a wall and cause discoloration.   Synthetic Stucco was introduced to solve these problems and for the most part they did. Since Synthetic Stucco is a lot like paint it dries more evenly. Because of the nature of the resin it moves more than cement stucco and is not as susceptible to cracking. Keep in mind nowhere did I say “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. Price was always the motivation of 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 still very affordable. So let’s go through and recap these products:

Synthetic Stucco

1.       Made of Co-polymer Resin

2.       Uses sand or other aggregate to achieve the look of Cement Stucco

3.       Resistant to water

4.       Crack resistant

5.       Color fast

6.       Comes  wet in pails

7.       Spread with an acrylic trowel

8.       More appropriate for dark colors

9.       Able to have smooth to very heavy textures

10.   More expensive than cement stucco

11.   Can be used over brown coat or in EIFS (Exterior Insulation Finish System)

Traditional Cement Stucco

1.       Made of Cement and Lime

2.       Uses different size sand to achieve different finishes

3.       Highly vapor permeable

4.       Comes dry in bags

5.       Spread with steel trowels and floats

6.       More of a “natural look”

7.       Less expensive

8.       Can be used over brown coat, continuous insulation systems, base and mesh.

As you can see there are more differences than first meet 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.


  1. Its like coming down to getting yourself a nice metal roof, or a bunch of asphalt shingles for your home. Its preference, but I would go with synthetic. It just has alot more benefits and pros.

    -Adam Ahmed
    Stucco Bronx

  2. I need to find someone to do some stucco repair in Albuquerque NM. My daughter ran into the corner of the the garage door and damaged the stucco.

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  4. I am very amazed by the information of this blog and i am glad i had a look over the blog. thank you so much for sharing such great information.
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  5. Never knew there was different kinds of stucco. What is better of the two, I live in California.

    1. Hello Mistie, Thank you for taking the time to read our blog and leaving your comment. For residential living in California, we would suggest our Real, Portland cement based stucco because the material is natural on the wall opposed to the acrylic, which is synthetic. Acrylic plasters are most widely used on commercial projects for easy maintenance on large projects. However, there are some homeowners who prefer synthetic stucco on their home so it looks more uniformed and exact.What it really comes down to is one's own preference. Hope that helps. Thanks again.

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  7. What is the best way to clean synthetic stucco??

    1. Thank you so much for your question. I apologize for not getting back with you sooner. The best way to clean synthetic stucco is to use mild detergent and soft brush. If it was due to paint or a concrete splash, then you'll have to redo the acrylic finish. Hope that helps. Take care. Thank you again for your interest in our blog.

  8. We are considering buying a home built in 1998 in the upstate South Carolina area (in valley surrounded by Blue Ridge Mountains) that is partly stone and partly artificial stucco. We have never owned a stucco home. Should we have it inspected before buying? Does it require maintenance? Can we add on a garage to the home and maintain the integrity of the exterior safely? What is the longevity of the finish?

  9. We have a 100 year old home in San Francisco, CA. Some of the exterior walls have the original stucco others have newer stucco from the 70s. There are not many cracks, only one visible one where an addition was built in the 70s. All the stucco contractors we contacted will address it. My question is, what is best, to put a 2 coat skim acrylic finish stucco system by Omega over our existing stucco or a 2 coat skim acrylic finish stucco system by Dryvit or Omega with mesh? (Which is better Dryvit or Omega?). Our house is built of wood (earthquake country). I understand that if moisture gets behind the Dryvit/Omega mesh walls it cannot vapor out like regular stucco, which breathes. Or does the Dryvit/Omega products of today have something in it that drains the moisture?
    Just to add to the info, we will get new windows and a new roof (before we do the stucco work).
    Thank you for your professional opinion!

    1. I have the same problem. I live in Oakland, CA and my house is 1927 stucco. I have water coming in all over the house and can be seen in the basement walls. I had windows replaced and they didn't seal them properly from the outside and the house is 3-stories tall on a hill with a hill driveway and narrow sides. Do I do regular stucco vs. synthetic vs. siding ? Please help.

  10. I have a beautiful home but I am told the trim around the home is synthetic stucco. Every year around October thru December woodpeckers drill many holes in the stucco. I patch and repair the holes in February. How can I replace or treat this problem permanently

  11. Our builders made a mistake with the color of the synthetic stucco they applied to our newly built home. They have offered to re-stucco the entire house in the right color or paint it with an elastomeric paint. Their preference is that we have them paint it and have suggested this is the better option because it creates another protective layer for the home. Is this true or are they trying to convince us of the cheaper option? Our preference is to have them re stucco the house but we are not sure if this is what we truly need to ensure the quality and longevity of our house.