Having been given the opportunity in applying elastomeric paint on a wide range of substrates, I have had the experience in dealing with both the success and failures of it. With the right elastomeric and the right substrate, in my opinion there is no other paint that can give an exterior substrate a better result. It bridges those unpleasant hairline cracks, expands and contracts to prevent future cracks from appearing, shields out moisture, resists mildew, has great wash ability, and the beauty of the angular sheen finish that will last years. However, it would only take one elastomeric failure to have second thoughts on it. Usually the failure is resulting from poor preparation, improper application, the wrong elastomeric product was applied, or the substrate not being a good fit for elastomeric at all.
To help you better understand, here is 3 characteristics qualities I want to briefly touch on, Bridging, Elasticity, and Water Vapor Permeability (prem rating).
- Bridging – is when the coating film becomes thick enough to act as a bridge over a gap or crack through its cohesion and elastic qualities. DFT (dry film thickness) range from 12-24 mills
- Elasticity – The flexibility of the paint film. elastomerics elongation ranges from 160% – 360%
- Water Vapor Permeability – (prem rating). – The ability of the coating to permit water to pass through it. Elastomerics range from 5-22 prems
There are 2 types of elastomerics, one is the standard which I call the high build, the other is known as a hybrid. It is important that you have the proper elastomeric for your substrate. If not, you could be looking at issues like thisThe above picture is a commercial building I drive by daily. They originally painted the building with a regular paint, but big cracks appeared as the building settled, they had it repainted in a high build elastomeric for cosmetic reasons, it was a face lift that went all wrong.
The heavy build was the 1st elastomeric coating on paint manufacture shelves. It was designed to be a water-proofing coating. With that it had to be thick to bridge cracks (up to1/16”), and the elongation to prevent cracks from surfacing so water could not intrude. The heavy build elastomeric has a softer shell than a regular acrylic paint and gets softer in hotter elements. With it being soft it is easier for dirt to stick to it, dirt can actually embed itself in the coating. It is important that the coating does not break or tear, the substrate has to be free of open areas like around windows, vents, pipes, etc. The structure needs to be examined for any potential area where water can intrude to determine if the heavy build is the right fit. Due to its low prem rating (2-4), if moisture penetrates it can get trapped between the substrate and the heavy-build elastomeric. The coating would then do its job, just on the wrong side. It will shield the moisture in, with the elasticity it creates those water balloon bubbles you seen in the above picture. The heavy-build has its uses on the right substrate, most residential structures are not. The heavy build is mostly used on commercial buildings. Most paint manufactures won’t even have it available, as they have recommended residential painters to use the hybrid.
As residential painters begin to use the high build, some were creating their own elastomeric paint by mixing 100% acrylic flat paint with the high build elastomeric. This would turn it to a medium build elastomeric, with a higher perm rating, less elasticity and more resistant to dirt pick up. Paint manufactures were getting concerned with painters making their own paint in the field. As a result they started formulating a new elastomeric product which is considered the hybrid elastomeric. The hybrid elastomeric is a medium build 100% acrylic with the 3 characteristics qualities of elastomeric, bridging, elasticity, with a greater water vapor permeability rate. Unlike the heavy body the new hybrid could be applied on both stucco/concrete and wood, including bridging those vertical cracks in T 111 siding with the elasticity to keep them from appearing for years. The hybrid elastomeric has a harder shell with the ability to maintain its shell in warmer clients, meaning it can also resist dirt pick up. The new hybrid elastomerics have exceeded both manufactures and applicators expectations becoming a premium coating to apply on an exterior surface.
It is best to consult with a professional paint contractor that is experienced with elastomerics in your demographic area.. The following hybrid elastomeric products I recommend on the right substrate. Vista Paint 1900 Weather Master, Sherwin Williams Loxon xp, Glidden Decra Flex 300, and Dunn Edwards Paint Endurawall
Great information, thanks for sharing your knowledge!
RCP
Great information, and I will be sure to refer anyone asking a question about elasto to this article.
Tommy Johnson
I have a customer with elastomeric (behr) coating on stucco. Stucco has major bubbling due to efflorescence. I was recommending not going with an elastomeric over elastomeric, I use Dunn Endwards and was inquiring if D&E’s Evershield will adhere to behrs elastomeric.
thanks
Mark
To answer your question Yes, Dunn Edwards Evershield will work without a warranty. You are absolutely right in recommending against applying another elastomeric coating on top of the existing coating, by doing so it can intensify the problem.
After researching BEHR Elastomeric I have come to believe it is a product you would want to run from. It has a very high elongation (600% with 3 coats), with a DFT of 13-15 mils. I cannot find a perm rating for the BEHR elastomeric, most likely it has a low perm rating being the final DFT is high along with a high elongation. This can result in trapping the moisture behind the coating, if moisture was to intrude. BEHR Elastomeric product looks to be an out of date elastomeric.
Here are my recommendations for a cure
For a cure with a warranty:
It is not recommended to apply a non-elastomeric coating over an elastomeric coating, unless the elasticity has expired. If it has not expired, the non-elastomeric cannot handle the expansion and contractions over the elastomeric. Being that the Behr product has a high elongation; the non-elastomeric can’t handle that elongation. It can result in the top coat cracking and/or a cohesion failure. The best cure would be to remove the elastomeric (sand blast) get it back to the raw substrate. But we all know that could be a very expensive cure and frankly just unpractical.
Non warranty cure:
1. Cut out affected areas
2. Spot prime (preferred oil base) the areas you cut out.
3. Patch where needed.
4. Apply a preferably oil base prime to seal all unseen pin holes.
5. Apply 100% acrylic paint (Dunn Edwards Evershield)
Going with this method you or your client will need to watch the substrate for the next 5 years or until the elasticity of the original coating has expired. There may be other affected areas that will resurface, usually during or after a rain storm. The key is to fix it with the above method as soon as it appears. So make sure you talk to your prospect for a maintenance plan. You will need to warn them that if the issue resurfaces to contact you immediately. If they don’t the affected areas can lay back down making it harder to find.
ewingpainting
Great info on this site, thanks for sharing your knowledge.
I’m undecided if I should use a hybrid elasto or an acrylic latex to paint the exterior concrete foundation walls (above grade) around my house. The house is about 45 yrs old and other than a few small patch repairs I made recently and scraping off the old paint (in preparation for new painting) the walls are in good shape. I live in Toronto, Canada and would appreciate your input if an elasto (more specifically the Decraflex) is ideal for this application or if a good exterior latex is suitable enough. Also, do you recommend a primer? The Glidden paint store in my area suggested it’s not necessary. Any suggestions would be greatly appreciated.
Jason
Hello Jason, thank you for visiting my blog. I’m glad you found information here to help with your painting project.
It is possible to use DecraFlex on your substrate but, I would take into consideration that your structure may not have a weep screed or it is buried. I am a bit leery of apply elastomeric on a surface where water can not escape. A weep screed runs along at the base of stucco walls with drain holes, allowing moisture to escape. By sealing up a wall that has no weep screed, water can get trapped between the stucco and the coating.
Why are you thinking you need elastomeric? Do you have hairline cracks? If no, DevFlex may be overkill. A good exterior 100% Acrylic paint like Benjamin Moores Aura or Sherwin Williams Duration would give you a long lasting finish. I don’t know Glidden Professional exterior acrylic paints well enough to recommend one.
Primers for concrete surfaces are mainly for bonders and resistance to efflorescence and alkalinity. If the surface is painted, it is not necessary to prime unless the surface is chalky, then a primer is a must. You do need to prime any patches you made or areas where paint has been scrapped off. There are benefits in applying a primer coat over a existing coating. It increases the adhesion strength between the prime coat and substrate, and the prime coat and finish coat. It Increases color retention, resists checking and cracking, Alleviates shadowing giving a better overall
finished product.
I hope I answered you question. Feel free ask if you have any more questions.
ewingpainting
Hi …and thank you for your professional opinion on elastometric paint. We live in Maine and just purchased a home in Florida. I have never had to paint a stucco exterior house as all the houses in New England are wood or vinyl exteriors. Ben Moore and SW have worked very well up here but I was quite unsure about the right paint to use on the east coast of FL. I am now leaning toward a good exterior latex paint.
Tim
Hello and thank you for visiting my blog!
I am in California where 90% of housing has stucco/concrete exterior surfaces. I don’t think it would differ much in Florida. Since you have had good result with Sherwin Williams and Benjamin Moore, I will recommend their products for exterior stucco, as I have had success with them myself. I highly recommend you follow the product specs, as I do not know the condition of your surface. The links are provided bellow, for Benjamin Moore click on Technical Data Sheets Even though the products spec no primer needed, I would recommend priming to achieve a premium long lasting finish.
Sherwin Williams – Duration Exterior Acrylic Latex
Benjamin Moore – Aura Waterborne Exterior Paint
ewingpainting
Thanks for your advice, I think after reading your response I’m leaning towards using the Duration, it will probably be more than adequate for the application I’m doing. What primer do you recommend using with the Duration? I was thinking two coats of the Duration should be OK, the first coat as a primer and then a second top coat (flat) finish. Also, does the Duration have a good perm rating?
Jason
If the substrate is raw, meaning never been painted before, I would recommend priming with Sherwin William Loxon Primer. Even though Duration is a self priming paint, priming will increase the adhesion strengths, resistance to alkali and efflorescence, and the longevity of the coating. I would do one coat primer and 2 coats finish for premium results, however 2 coats of Duration will do the job. if the surface is chalky it is a must to prime.
“Moisture vapor is more likely to pass through acrylic latex paint films than through solvent alkyd types. It’s true that application of additional coatings will reduce moisture vapor transmission, simply on the basis of increased film thickness. However, even with several coats applied, the latex film will be adequately permeable to water vapor and better than alkyd paint films of comparable thickness.” Sherwin Williams FAQ
The perm rating with paints like Duration is not as important as dealing with elastomerics, because elastomerics act as a water proffer, Duration is not. Sherwin Williams does not specify it because it is not a issue, as Duration is more adequately permeable to water vapor.
ewingpainting
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I have a customer whose stucco home in Arizona is painted with Dun Edwards Elastomeric. Prior to painting they applied XTS Caulk to fill all of the many cracks. They put 4 sprayed on backed rolled coats. The paint has not cracked in any place.
The issue is that where the XTS Caulk was used, you see a more original color versus a washed out (chalked) color. I was told that because the XTS had a higher UV protectant, is has leached through the elastomeric and those reduced the chalking/fading impact of the sun.
The home owner wants to paint the house again using elastomeric only he wants me to add a lot more UV additive to the Elastomeric to avoid any future show through. What is the formula or recommendation for adding the UV additive per 5 gal pail and do you highly recommend any UV product and or elastomeric paint.
The customer is very intelligent and knows a lot of potential high paying influential customers so I do not want to have him ticked at me in five years as I continue to expand my painting business… need all the referrals I can get.
Thank you,
John Clearwater
John Clearwater
Hello, thank you for posting on my Blog! I do apoligize for not replying sooner, my grandmother has just passed away so I have been dealing with that.
To better understand you I would like to move the communication through email so I can better understand the issue. After I get a clear understanding I will reply here so others may benefit from this as well.
Thanks, and I will wait for your answer.
Gabe
ewingpainting