Stucco’s Versatility on Display at Claremont Colleges

Founded in 1887, Pomona College and the other seven Claremont colleges are a striking demonstration of what stucco can do in different architectural styles. From the contemporary smooth-troweled Santa Barbara Finish at Claremont-McKenna to the machine dash finish on the oldest buildings at Pomona College, the Claremont Colleges really show off the best that stucco has to offer. These photos were taken on a recent visit to campus.

1Pomona College has the most traditional architecture and uses machine-dash 16/20 stucco to create a California Gothic collegiate feel.

2A stone’s throw away, Claremont-McKenna recently built a contemporary dormitory with smooth-troweled Santa Barbara Finish stucco and poured concrete. Smooth-troweled finishes allow for natural looking color variation and sleek lines in virtually any color.

3Across the walk path, this Claremont-McKenna dormitory is made of pebblecrete stucco. This is a unique look, made by embedding larger aggregate in the cement stucco and then exposing it through the use of mechanical grinders or chemical washes.

4Stucco can also be used to create boardform looks in a variety of colors.

5The award-winning student center at Claremont-McKenna used Vero lime paint to stand out from all the other striking buildings on campus. The lime paint gives a soft watercolor appearance with natural color movement.

6Even the boutique hotel Casa 325 showed off an innovative stucco finish; the designers chose a coarse 16/20 stucco troweled down to create an interesting texture different than the traditional application methods of sponge floating and lace texture.

Another photo of Kravis Student Center at Claremont-McKenna:


Homeowner Repair Continuation…..

As you recall I have a hillside house with planters on either side of the driveway. Water had been eroding the stucco on my house for many years. I scraped off all the material in some cases back to the CMU (Concrete Block). Then I applied Super Blockade as a waterproofing material. It would have been better to put the waterproofing material on the positive side (inside the planter) but it would have been a huge job to remove all the soil, weed cover and the landscape bark. So this is the next best thing. Following the Super Blockade I used LevelX to base the wall out and bring the material up to the level of the existing stucco. While it was curing I removed a small piece of stucco from the wall and took it into the Merlex lab. The lab guys matched the chip and gave me a new Merlex “P” number to order stucco. I had them make it in premix so I could use a drill and paddle to mix the material. I also bought some Acrylex at the same time to add to the stucco to insure the bond over the polymer modified base coat. Last Saturday we applied the Santa Barbara Finish and the color was really close! I know over the next six months it will look exactly like the rest of the house. The guys that did the smooth stucco were really good and actually took a day and a half to apply just 7 sacks of stucco! This shows how much effort it takes to make a smooth job look good. I waited three days after they were done and then applied Micro Seal II to the stucco. This is the last step in the attempt to keep moisture out of the finish material and not have a re-occurrence of the delamination.

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Homeowner Wall Repair

When I bought my house, the previous owner had not waterproofed the walls behind the planter areas. I re-stuccoed the entire home using a Santa Barbara Finish. Within a year or so I began to notice efflorescence and a resultant spalling of the stucco surface just behind the planter areas.  I knew the best fix was to waterproof the positive side of the wall. That is, the side with the dirt and moisture in it. However, as with most jobs like this, I did not want to dig out the back in the wall.

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So I did the next best thing:

1. Using a 3 lb. sledge hammer and a wall scraper. I removed any material that was punky, spalling, or sounded hollow. This is the concept of: “the next coat is only as sound as the surface you are going over.”

2. I mixed up and spread Merlex Super Blockade to stop the water or moisture from coming through. I made sure to put on at least 2 coats.

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3. I then used LevelX to cover the Super Blockade and also to build up those areas that had been removed. I added some Acrylex to the Levelex to ensure a good bond. In some places it took two coats to build up the material level with the existing Santa Barbara Finish that was remaining.

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4. There were some areas the Santa Barbara finish was still functionally good but pitted and ugly from the damage cost by efflorescence. We rolled SuperHold on the smooth surface before applying the LevelX. Again this is to insure bond of the subsequent coat.

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At this point, the wall is ready for stucco.


Stucco should go on next week…. I will send the final pics and any comments following…


Faith In The Stucco Industry Continues – Part II

On Tuesday, I walked Phase I of the Plaza San Clemente Outlet Mall project, which is using our exterior plaster system. It is coming along nicely. Brady seems very pleased how the materials are spreading and their professionalism and attention to detail continues.


Phase I of Plaza San Clemente is approx. 40,000 yards. Phase II will follow with 27,000 yards. The system implemented on the majority of the walls is Densglass fiberglass faced water resistant gypsum board screwed to the studs; 60 minute paper (WRB) is applied over the board with 3.4 metal lath installed over this to hold the first pass (scratch coat) of mud. The mud consists of factory blended and sanded Insulex fiber reinforced base coat material by Merlex. The scratch coat is field mixed using a mixer and pump to apply the material directly on the metal lath. The material is then tooled to introduce furrows typical of the scratch coat. Brown coat is applied following a two day cure time. The brown coat is tooled flat using a Plaster Rod and tooled with trowels to introduce the subtle mottling required by the scope of work. After another two day cure time and the third coat is applied. This third coat is a relatively new addition to the plaster system and is known as “Base and Mesh” or the “bed and mesh” system. It is also characterized as Crack Resistant Coat or Crack Isolation System. Merlex Basex is applied by Hawk and Trowel over the tooled brown coat and, while still wet, the mesh is embedded into the material. The  4 oz Alkali Resistant fiberglass mesh is worked into the material to create a barrier to stress. The polymer in the Basex also serves to absorb some stress as it emanates up from the natural movement of the building. As soon as the next day Merlex Santa Barbara Finish can be applied from the top down to create the early California look desired. The subtle humps and bumps are barely perceptible but are sure to add to the natural beauty and traditional look of bygone days. The architecture calls for long planes of material using no plaster stops as Control or Expansion Joints. These tend to break up the field and long stretches of wall and most feel they help in crack reduction. The further benefit to these breaks is to allow a stopping point for the labor as they tool the smooth finish on the wall. Without a stopping point it is common to get “cold joints.” These are where an area of finish dries before the next step is started. In a natural application (without paint) this is to be avoided at all costs. However, because the entire job will be painted, it is only a matter of patching these “joint” areas and sanding them out before painting.








There is a detail at the bottom of the wall where it is furred out 1 ½” to give contrast to the rest of the wall. This will be 16/20 float finish.


Super Blockade Water proof Cement Material is being applied at the local foam plant (Foam Co Products in San Diego) to stand up to rain and moisture of the large dome caps on the corners throughout the project. Each cap specifies Santa Barbara smooth Finish (Color P-7851) modified with Acrylex to properly adhere to the waterproof material.

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With all this said, Phase I of the project is coming to completion soon, and is going to look great with the right team behind it. We’ll keep updating each section of the project.



    San Diego, CA (June 24-25, 2015)- MERLEX STUCCO, [manufacturing stucco, acrylic finishes, and waterproofing products since 1963 in Orange, CA], will showcase its newest products and solutions in San Diego, California at the homebuilding industry’s most anticipated west coast conference and exhibition, PCBC. As the only industry event that partners with the Leading Builders of America, PCBC 2015 will gather close to 10,000 high quality buyers representing every segment of the industry: homebuilders, developers, architects, building scientists, lenders, investors, marketers.
    From June 24-25, prominent industry leaders will gather to present the latest product, trends and innovations both on the show floor and through the high-level education program.
    Established in 1963, MERLEX STUCCO has since expanded opening two warehouse locations in Los Angeles and San Diego counties.
    Merlex Stucco will be exhibiting again this year in San Diego because “PCBC is the perfect opportunity for us to connect with top quality professionals in the residential building space,” explains Melissa Higgins, Director of Marketing, Merlex Stucco. “We’re showcasing our products to a highly qualified audience—including representation 21 of the largest publicly and privately held homebuilders in the nation. On top of that, we are building relationships to carry on throughout the year.”


    Merlex will debut a newly designed display booth along with a few new products at BOOTH #130 and invites professionals in the industry to visit us. For more information on the educational conference and schedule, visit

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      About PCBC:

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    Dedicated to advancing the art, science and business of housing, PCBC is the largest homebuilding tradeshow representing the west coast region. Launched in 1959 as a small educational conference at the Sheraton Palace Hotel in San Francisco, PCBC is now an annual two-day conference, product display and business exchange and is open to anyone professionally involved in the building industry, including builders, developers, architects, remodelers, designers, contractors, dealers/distributors and suppliers/manufacturers.


C R & Sons use Merlex products to remodel to perfection



I had the pleasure of talking with C R & Sons on the jobsite this week and drawing on their combined 100 years of experience with remodeling projects.  They really are among the best plastering companies in the area, and have been for decades.

On this project, they had to install weep screed and J-metal trim on the garage, then patch in level with the old stucco.  They used our PSB Premium Scratch & Brown product, “which is factory blended with plaster sand and additives in order to get good hang and spreadability. The guys added Luminate cement to accelerate the set, so they could patch and apply the next coat the same day.” 


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Lupe applying PSB


The house had a combination of substrates… some new brown coat, some painted old stucco, and some unpainted old stucco.  The customer wanted to minimize cracking on the smooth-troweled Santa Barbara Finish, so Ciro’s crew applied a flexible polymer-modified, Basex crack reduction system with embedded mesh over the entire surface of the house, after water blasting off any loose material. This evened out the differential suction to achieve an even finished appearance, ensured bond even over paint, and will prevent up to 90% of cracking.

Alex applying base and mesh (Basex) crack-reduction system

Alex applying base and mesh (Basex) crack-reduction system

They applied the Santa Barbara Finish the next day and the walls look great… even color, solid bond, and so far no cracking.  These guys know what they’re doing, and Merlex products are perfect for these types of jobs.

New Faith in Stucco Industry


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I spent a day with the Brady Company on the job in San Clemente last week, and their professionalism and attention to detail renewed my faith in the stucco industry.   They were applying the scratch coat to the first building of an outlet mall to beat all outlet malls.  This one is perched atop a hilltop in the most charming beach town in Southern California, and has Pacific Ocean views to go with the great shopping.  They are pumping our Sanded Insulex product as their scratch and brown coats, made with washed clean silica sand, factory blended so it’s the same ratio every time. Insulex is blended with fibers for improved strength and sag resistance allowing for accelerated job scheduling due to reduced wait times between plaster base coats. Our flexible polymer-modified, crack-reduction system (Basex) is then being applied as the base coat, specifically designed for smooth coat finishes. One of the key advantages of using our base and mesh system (Basex) is the fact it withstands cracks in the base coat up to 0.04 inches without cracking through the finish coat. Lastly, Brady will apply our Merlex Santa Barbara Finish smooth-troweled stucco as the finish coat. san clemente1 These guys from Brady are pros.  The mixers, Ernesto and Ismael, followed our mixing procedures to the letter and stopped the mixer after a few minutes to break the set.  Not many crews follow that instruction, although it’s on every one of our technical data sheets and gives the plaster better workability and open time.  I saw Ernesto checking the slump of the material before sending it to the Tommy Gun several times.   The hose crew was just as good.  Joe ran the nozzle this day to set the tone for his guys, who were hustling to move the hose, trowel out the scratch coat, and keep the trims clean.  They worked calmly and efficiently and together, communicating with each other to ensure they did the best job possible.  The nozzle and mixer talked frequently by walkie-talkie to ensure proper speed, coordinate breaks and lunch, and fine tune things.  Chuck Cannon, their plaster superintendent, did his part to ensure their success, adjusting the hose configuration, reminding the guys of standard operating procedures and safety issues, and getting the right people in the right places. san clemente 4   This is the first time I’ve blogged about a work crew.  But these guys made me believe that our products are in good hands out there, and that our industry can be successful in rising to any challenge that comes our way in the field.

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Sunrise over the jobsite

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When Choosing Stucco Colors, Beware of Color Pigments

There is always quite a stir over colors in stucco. The designers, architects and owners want the colors that will make the project sell more quickly, add appeal, match existing schemes and make an aesthetically beautiful project. The contractor warns that heavily pigmented colors are expensive, troublesome and susceptible to problems. What is the answer? It is of course complicated and pros and cons must be weighed. Let’s start with the most asked questions about stucco and color:

  1. Pigments are expensive and when you get over a pound the price goes up? This is true. Typically manufacturers allow one pound of pigment in a sack of stucco with no extra charge. Blue and Green are the exception as they are more expensive colors. Pigment is by far the highest cost raw material in stucco by weight. When custom homes want that rich earth tone with four pounds of color it can be as much as twenty dollars extra per sack. Remember though, if we are talking about a high end custom home then the homeowner should get what they want for an exterior color. A very large custom home might use 100 sacks of stucco and even at 20 dollars this is only 2000 dollars more.
  2. The contractor says he has a hard time making stucco even and consistent with heavily pigmented colors? This also is true. However keep in mind what texture is wanted. A lace texture or sand finish is very unsightly with mottled color. In this case the wall would certainly have to be fogged to even out the color. In smooth finish applications color mottling is typically required. With darker colors we see movement and character in the stucco. It becomes a benefit and part of the artistic beauty of the finish.

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  1. Are some colors so dark that fog coat cannot be produced for that color? This is a common assumption and most stucco manufacturer s have specified limits to making fog coat with over 4lbs of pigment. The reason is that fog-coat comes in a 25lb bag. If there are 5 lbs of color in the bag that constitutes 20% of the bag by weight. We cannot take that much cement and other ingredients out of the bag to accommodate this much color. Similarly, we cannot produce heavily pigmented pre-mix stucco for the same reason. We never want to put so much color in the bag that it threatens the integrity of the product. We should be able to produce fogcoat that can even out color variances using dark pigments. The solution then is to make fog-coat in base and color and let the contractor mix it in the field.
  2. Are colors more “problematic” when they are dark? Yes, stucco is certainly not paint. It is not logical to expect stucco to react as paint does. Weather plays a huge part in how stucco looks and the more pigment involved the more the weather and other variables can affect color. Efflorescence is more noticeable in darker colors. It is not because there is a higher presence of salts, it is that salts are white by nature and show much more on darker walls.


  1. My contractor has asked me not to use the dark color I want for my home. What should I do? It is your home and being the owner or builder you should have what you want. But… Go in with your eyes open! He doesn’t want to do it because he has experience that there are many things that can go wrong and he knows that he will be blamed for the problems. My advice is to:
  2. Always do a mock-up and agree on the color before starting the job.
  3. Discuss mottling, efflorescence, extra cost and find the tolerances and expectations of both parties and put it in writing!
  4. Discuss what to do in the event of freak storms, repairs resulting from damage by other trades and who will pay for these issues.
  5. Weigh the pros and cons very carefully when choosing color.

Remember, stucco is by nature a natural product. All the raw materials are from the earth and it is almost always hand applied. This is the beauty of the product. We don’t have to re-do it every few years like paint. Stucco has an extremely long life cycle. So like any natural product or handmade material certain allowances must be made for the very nature of the product. Life is a give and take so go for that dark color on a smooth wall! Enjoy the beauty of the staining and mottling the same way you would admire your handmade antiques with all of their beautiful imperfections!




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The rainy season has finally hit Southern California. For those of us in the stucco business lots of rain can only mean one thing: EFFLORESCENCE!

This is the white powdery material we see on concrete, masonry, stucco and other substrates that are naturally high in alkaline. Usually about a week following the rains I get quite a few calls from builders and homeowners letting me know that “the lime is coming out of the stucco”! I patiently explain that these are naturally occurring mineral salts that are present in plaster, cement, stucco, mortar, stone, soil, water, and many other materials used in construction. In some cases the efflorescence can manifest itself as a “bloom” of white calcium carbonate and have a crust. The water soluble salts liquefy and as the wall dries the water migrates to the surface carrying the salts. The water turns to vapor and evaporates leaving the salts on the surface in the form of efflorescence. We see it most often in new construction where the salts are in higher concentrations. But efflorescence can occur over time as long as the salts are present and the conditions exist for them to migrate to the surface. Slower evaporation also tends to allow more salts to come to the surface and obviously large amounts of rain exacerbate the condition. The good news is that these salts can be neutralized. Since these salts are by nature extremely high PH it is logical that a low PH solution (an acid) should be used to neutralize it. On a smooth wall or masonry you can use a soft brush and a mild solution of white vinegar and water to kill it. On tougher staining or textures that can be damaged by scrubbing then a stronger acid solution can be used. Be extremely careful however, acid can etch glass, kill plants and is very caustic and hazardous to use. One method for removal is to dry brush the calcium off and then flush the area with water. This seems counter intuitive to add more water but since there is a finite amount of salt it does work. After cleaning a sealer can be used to stop water. Merlex’s Micro Seal is an excellent chemical for stopping water. If the water cannot get into the wall it can’t carry the salts back out. So the next time it rains just get out the vinegar and don’t blame it on the lime!

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A Flurry Of Activity Around Energy Efficient Stucco


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Merlex representatives are fielding an increasing number of questions about how to build energy-efficient stucco walls.  These systems have existed for decades, but are getting a boost from the California Title 24 energy efficiency standards that went into effect on July 1, 2014.

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Insulex, Continuous Insulation One Coat Stucco System


Some of the most common questions we have been asked are:


  • How can I use stucco over “CI” (continuous insulation) foam board?
  • Will CI stucco systems (a.k.a. 1-coat stucco) be less durable than traditional 3-coat stucco?
  • Is there a cost difference between 3-coat and 1-coat stucco?
  • Are contractors in California trained to properly apply 1-coat stucco?
  • Does 1-coat stucco have a strong “bang for the buck”? That is, will 1-coat stucco cut energy usage significantly more than all other design alternatives with the same cost?
  • Can 1-coat stucco go over open framing?
  • Does 1-coat stucco have a fire rating?
  • What if we combine 1-coat stucco with other siding materials and there are different cladding thicknesses on the wall?
  • What if the foam board fasteners miss the studs?
  • What happens to windows and accessories like weep screeds when the thickness of the stucco increases?
  • What alternatives are there to 1-coat stucco if I decide not to use it?


Merlex’s President and Vice President are touring the State right now with an informative presentation on this subject, and would welcome the chance to present to architects and builders interested in these and other questions.  The industry needs to learn more about 1-coat stucco, such as Merlex Insulex, and what it can do to help them build more energy-efficient buildings.






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