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How Long After Foam Application To Apply Acrylic? Post New Topic | Post Reply

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Tim Adams Posted: Jun 20, 2013 08:02 AM	How Long After Foam Application To Apply Acrylic? We've been told everything from it has to be the same day as the foam was applied, to within 3 weeks.
james keegan Posted: Jun 20, 2013 09:23 AM	Hey there, let the foam setup so you have a good and firm surface. Once it's set up you're good to go and apply acrylic. If you wait, you could deal with moisture from rain or dew. Make sure you're not spraying in windy conditions, otherwise waste no time. Good luck...James
SprayFoamSupply.com Posted: Jun 20, 2013 02:16 PM	You should base coat any foam that is sprayed the same day. Look at some foam that was sprayed in the morning and then look at some sprayed in the afternoon. The morning foam has yellowed some as the UV degradation begins as soon as the foam is sprayed. Even though, you shouldn't have adhesion issues if you coated the foam the next day, there is always a risk that you can't make it back the next day; unforcasted rain, equipment issue, truck issue, accident, etc. If you have the base coat on, then you have a safety net until you can get the final coats on. George
mason Posted: Jun 27, 2013 10:44 AM	Sorry about the delay in responding to this inquiry, was out of town and had problems getting internet coverage. I presume you are referring to an exterior or roofing application. The foam needs a little time to off gas, typically 1-2 hours. You should as George suggested coat all exposed foam the same day as it is applied. But, be sure to leave sufficient drying time for the coating. For example at 75 degrees F and 50% humidity, it typically takes about 2 hours of drying time for the acrylic coating to have sufficient cure so that dew or rain will not affect it. If you coat past your window, then dew or rain can mix with the coating and it will not cure properly, leading to poor physical properties and adhesion. In colder climates and in higher humidity it will take even longer. So, it is important to stop spraying foam to give yourself 2-4 hours of drying time for the coating. Be sure to ask your coating supplier for their specific recommendations and drying times in various climatic conditions.
Tim Adams Posted: Jul 03, 2013 09:28 PM	If the foam is to be coated with 9 gal per 100 sq. ft and 3 lbs of chopped fiberglass per 100 sq. ft., do the same "coat the same day" rules apply? FYI, one of emulsion's uniques features is that it adheres well to just about everything. In fact we have sprayed it over some really cruddy looking SPF roofs that had been exposed to UV by hail for years and had nearly disentigrated. Shoot 9/3 over it and it lasts many years. Another feature is that emulsion doesn't blister. So, what is the risk in letting new foam set for a few days before coating with emulsion?
mason Posted: Jul 08, 2013 08:03 AM	Boyd, As chair of the ASTM Committee on SPF Roofing, I would be very cautious of using the system that you describe on SPF roofs. I am not familiar with the coating system you are using, but it not a typical covering for SPF roofing systems. One of the main attributes for a coating over SPF in exterior applications is elongation. We recommend 200% elongation after weathering. This allows the foam to move slightly without cracking the coating. As for letting the foam sit. Delamination is more likely when you let the UV attack the foam, even for a few days. The foam forms a high density smooth skin that is more slick than when it is first sprayed. After a week or more, the foam skin turns to a fine powder which has even less adhesion. There are many brands of high tensile strength elastomeric coatings that have a great track record over foam that are extremely resistant to hail. I would characterize the covering system you describe as "experimental". As such, I would want to have independent investigation performed on the system by a responsible group that is knowledgeable about SPF roofing systems. The investigation would include field inspections in various climates in addition to evaluation of the physical properties of the covering. It is better to use a tried and true covering over one that has not been investigated by the SPF industry. I also wonder on how you would re-coat this system. I expect you would have to tear it off at the end of its service life. One great feature of SPF roofing is the ability to extend the life of the system by re-coating the roof.
Tim Adams Posted: Jul 08, 2013 09:36 PM	Mason, thanks for your response. To reply to your last question, one of the attractive features of Bentonite Clay emulsion is that it won't blister. We have older emulsion roofs that have been damaged by hail and recoated with emulsion 3 times, not a single blister. I read where at least one SPF chemical mfr suggests emulsion over a hail damaged scarified roof as the black draws out the moisture, then the roof is coated with a reflective coating. We don't want to reinvent the wheel, just looking for a way to offer customers an SPF roof that doesn't need recoated in 10 years.
mason Posted: Jul 09, 2013 08:05 AM	Boyd, The coating system you are promoting has not been investigated or vetted by the SPF industry. In the 42 years I have been in the SPF industry, I have seen dozens of covering systems attempted, most with lousy results. Just stick to the tried and true systems that have been used for 40 years. As a "newby" I appreciate your creativeness, but please remember, there is 50 years of experience with SPF and coatings that you should consider before attempting something that doesn't have the same field history. In order to have the industry investigate your system, contact Rick Duncan with SPFA (rickduncan@sprayfoam.org) or call 800-523-6154. There is a new product protocol that the SPFA uses to investigate covering systems. For example, the protocol was used in the 90s to validate the use of aggregate as a covering over foam.
Tim Adams Posted: Jul 09, 2013 12:01 PM	Thanks, Mason. I was sure I'd read that some spf mfrs have a spec that uses emulsion, at least to dry out moist hail damaged foam. So I called one of the largest of them this morning, a company we have an affiliation with, and they told me they like emulsion over foam. We won't be experimenting on customers' roof, that's for sure. That said, we won't be trodding the beaten path all the time either. :-) My dad has been a roofing industry pioneer for 47 years with over a 12 innovated commercial roof systems, equipment, processes, etc. If he finds himself at the stoplight for more than 30 seconds, his mind wanders off trying to invent a better stoplight. :-) I suffer the same affliction myself. We will not be doing anything that reflects poorly on the spf industry, but we will be heavily-ivolved in trying to build a better mousetrap at every juncture. The need of recoating foam roofs every 10 years seems to be a place ripe for improvement. Of course, I am reminded that we're still trying to grasp some of the fundamentals and will be careful to walk before we run.
Tim Adams Posted: Jul 09, 2013 06:19 PM	I wanted to make sure we're not on thin ice here so this afternoon I spoke to another highly respected and experience rep for a foam mfr. He said what I thought too, that applying emulsion over spf is fairly common in Texas. I feel a little embarrassed when on one thread I'm asking noob questions about chemical storage, shields, and equipment, then I have the audacity to want to change the way spf roofs are installed. I realize it appears I have the cart in front of the horse. But a lot of years in the roofing business taught me that methods that are thought of as experimental in one region, are often commonplace in another. That seems to be the case with asphalt emulsions.
mason Posted: Jul 10, 2013 05:12 PM	Boyd, I would like to know the rep so I could talk to him. I know most of the experienced folks in the industry from being on committees and roaming around the country. I am always interested in new ideas, but again, the industry should look at it from an objective, quantitative analysis.
mason Posted: Jul 11, 2013 03:46 PM	The online conversation with Boyd reminds me to caution anyone who uses a system that not been vetted by the industry. Your legal liability is increased 10 fold for the following reasons: The system is not recognized by any of the roofing organizations or spray foam groups such as RCI, NRCA, SPFA, Sprayfoam Coalition or ASTM There are no printed guidelines for application or inspection to verify the system is installed correctly. (foam and covering system together) The contractor has to take full warranty responsibility as the covering system manufacturer does not warrant their covering over foam and the foam manufacturer only covers a warranty under an industry recognized coating system The covering system needs to have been fire tested by UL or by Factory Mutual to comply with current building codes It could be a costly experiment if for some reason the roof fails.
Tim Adams Posted: Jul 11, 2013 04:08 PM	Mason, Some of that is incomplete. Or at least partially so. RCI, NRCA, MRCA, WSRCA, FM and many others recognize and have tested chopped glass emulsion roofing, known in the industry as APOC Monoform, Henry Company Monolithic, and originally as Flintkote Monoform. Emulsion asphalt for roofing has been around longer than SPF for roofing, and they have been used together many many times and I've never heard of a single compatibility issue. Incidentally, extensive fire testing haas been done by all industry testing entities on emulsion, and this is why emulsion has the unique feature to being Class-A fire rating supportable. In fact, just about every roofing system manufacturer specifies that an emulsion top surfacing is the only way their built-up systems can support a Class-A fire rating if gravel or granules aren't installed. Emulsion has Bentonite Clay - it doesn't burn. It is true that there are not 'yet' any specific specs using emulsion over foam, other than it being used as a drying agent for saturated hail damaged spf. But nor are there specific individual specs for most of the roofing materials installed over each and every possible insulation combination. Metro Dade, perhaps the tightest building code in the US takes the position that, as an example: since mod bit roofing is accepted, and emulsion asphalt is accepted, even though emulsion over mod bit is not specifically tested or approved, one is considered an enhancement of the other and is acceptable. It's been years since I research this, but that was Metro Dade's position then and probably still id. The point is that, in the absence of any reason to believe that spf and emulsion create an unusual chemical or physical reaction to one another, there shouldn't be any reason that 2 widely accepted, tested, and approved materials cannot be used together. They are in fact widely used together and nobody has ever heard of any issues. Has emulsion and spf been tested as a system? Evidently not, but there is absolutely nothing in the chemical makeup of either that would lead to think they aren't compatible. Since so many contractors are successfully using emulsion over spf, perhaps the various sanctioning bodies should take the bull by the horns and have the combination tested, rather than asking contractors to spend a lot of money testing a system they already know works.
Tim Adams Posted: Jul 11, 2013 04:39 PM	Henry 107 Emulsion: ASTM D1227 Type III, Class I UL & FM Approved: Manufactured to exceed the requirements of ASTM D-1227, Type III, Class I, Dade County Compliant. UL listed for Class A and B fire rated roof coverings. FM approved. Subject to the conditions of approval as a roof coating when installed as described in the current edition of the FMRC approval guide. Consult Henry Representative for specific assembly ratings and requirements. (800) 486-1278
mason Posted: Jul 12, 2013 04:30 PM	You don't get it. If you are talking about an emulsion roofing system that is different than a foam roof system. The system has not been tested or approved over spray foam. So all of those approvals are not meaningful The whole system is to be tested and adhesion is a big concern to me. Particularly if you are talking about letting the foam sit for a long time before covering it. Mason
mason Posted: Jul 13, 2013 08:51 AM	I know the folks at the Henry company pretty well and will call them for specific answers on the testing, and see if they have recommendations to the amount of time the foam can sit before they have to cover it. I suspect they are in line with the rest of the industry and recommend covering the same day and no longer than 1-2 days without an additional inspection to determine if the coating would stick.
Tim Adams Posted: Jul 13, 2013 07:30 PM	Mason, I think you made a transition here. We have gone from emulsion over spf not being acceptable because it hasn't been "vetted," to asking Henry how long can new spf set before emulsion is applied. Whatever Henry says is the right amount of time is ok with us, but I was of the impression you were saying that emulsion should not be used over spf at all because it hasn't been lab tested. Whether emulsion over spf has been tested by men in labs coats yet or not, it has been tested in the real world on millions of sq. ft. of roofing applications, and I know of not a single failure caused by incompatibility. One thing that I think is confusing here is that the roofing industry where you are, and the roofing industry here in the hailbelt, are dramatically different markets. I know this to be true because our mfg co has trained contractors in 39 states including NY, CT, VA, NC, and Toronto, and I can say without hesitation that we do things differently down here. You sell a lot of mfr warranties up there, we rarely sell them down here. In 20 years your customers might install a single flat roof on their building, while down here they will likely reroof it 2-3 times in 20 years due to hail. Thus, retrofits are more popular here. Thus emulsions that don't blister are popular here. Two very different markets.
mason Posted: Jul 14, 2013 10:18 AM	I want to talk to the folks at Henry because their website does not provide any specs or information about installing their emulsion over sprayfoam. They do have a section on sprayfoam roofing which has specs on using their acrylic, silicone and moisture cure polyurethane coating over spray foam. The specs for their sprayfoam roofing is consistent with SPF industry best practices as I have related in previous posts. The section does not mention using their emulsion coatings over sprayfoam. In the section on emulsion coatings, there is no mention of sprayfoam as a suitable substrate although it mentions others. But, in order to provide the most accurate information possible to our readers, I will discuss their emulsion roofing system. I specifically want to know if they have tested the system over sprayfoam, if they recommend it, warranty it and if there are specifications of its use of sprayfoam. As for my experience with hail and roofing systems. I lived a considerable amount of time in the hail belt areas of Texas and New Mexico. As as the national tech rep for E. R. Carpenter and as General Mgr for UCSC I inspected hundreds of hail damaged roofs. I also was responsible for testing our sprayfoam roofing systems for fire, wind, hail in order to market them and make them code compliant. As the technical Director for SPFA, I was responsible for industry wide testing of SPF roofing and coating systems at UL, and FM for over a dozen years. I also was the staff person responsible for overseeing the National Roofing Foundation study on sprayfoam roofs by Rene Dupuis that was published in 1997 with a follow up study in 2003. This study evaluated more than 350 sprayfoam roofs in many different climate zones in the US, obtained samples of foam and coating. Much of the industry's guidelines and assumptions were validated in that study. Working with another SPF expert Don Best out of Oklahoma city, I wrote SPFA's guideline for inspecting and repairing hail damaged SPF roofing systems. We also developed guidelines on how to design a SPF roofing system to be more resistant to hail. Both silicone and acrylic coatings can be made more resisitant to hail by increasing the density of the sprayfoam and the thickness of the coating. Additionally, granules or small aggregate can be installed in the top coat to further increase the impact resistance. Some coatings such as the moisture cured polyurethane coatings at the proper thickness are extremely resistant to hail. An application of a 3.2 pcf foam with 45 mils minimum polyurethane coating has demonstrated exceptional resistance to hail impact. There are other systems that have been vetted, tested and approved over spray foam that are also very hail resistant. For example, Carlisle Syntec's EPDM Fleeceback installed over spray foam with a spray foam adhesive. I first saw this system in the mid 80s when I was living in Dallas. At that time, Jay Venable a sprayfoam contractor based out of Kansas came up with an idea to use a fleece back EPDM rubber roofing membrane, installed over sprayfoam with a sprayfoam adhesive. He developed the process, got the testing done for wind uplift and UL fire ratings (UL 790) and brought the concept to SPFA for discussion. Eventually he sold the patent to Carlisle Syntec who developed it further got their FM approvals and began marketing it nationwide. Carlisle also participated in SPFA's technical committees. Another system is the aggregate covering that is marketed by NCFI. This system was originally developed in the Northeast and there was a lot of controversy about it at the time. SPFA at the request of the suppliers (both for and against the system), performed field inspections of the systems in 5 different geographic climates of the US using SPF trained RCI inspectors. The result; the system proved itself to be a viable alternative covering. Note; this system only requires coating on the vertical surfaces and within 2 ft from the edge of the roof. The horizontal surfaces are covered with 1.5 inches of aggregate. In this system the foam does not have to be covered with aggregate the same day or even the same week since the aggregate is a loose laid system. The coating on the vertical surfaces and edges does require same day coverage. My point is that even though there are many in the sprayfoam such as myself who are "dinosaurs", we still look for innovative ways to make our systems better. But, at the same time, we have through collective experience found out that some things work with foam and others don't. The concept of using elastomeric coatings on sprayfoam roofs is tried and true. Coating sprayfoam roofs the same day the foam is installed minimizes the potential for coating blisters. Waiting a few days or longer greatly increases the potential for coating blisters. Some coating systems are more likely to blister than others. It may be that the emulsion coatings could have better adhesion than some of the acrylic and silicone coatings, I don't know. But, if the foam has degraded to the point that it is dust on the top surface, anyone coating system will be compromised. We have gone on fairly long with this thread and a lot of good points have been made. I will wait until talking with the Henry company representatives before discussing it further.
Tim Adams Posted: Jul 14, 2013 10:50 AM	Mason, I understand that. I'm just suggesting that you don't imply that being tested/spec'd/factory-warrantied, and being acceptable are one and the same. They aren't. The vast majority of roofs around here do not have a manufacturer's warranty. That was my point, that here in the hailbelt things are done differently - I'd venture a guess that at least 50% of the retrofit roofs installed around here do not meet a manufacturer spec. The odd thing is that many roofers have critiqued our emulsion roofs that were left black because the owner was on a tight budget. Never mind that those black roofs are over 20 years old and the roofer critiquing them wouldn't know how to make his own roofs last 20 years to save his rear. My experience is that the building owner cares a lot more about how many dollars per year of life his roof will cost, than he does about whether that manufacturer spent the money to test every possible material combination.
mason Posted: Jul 15, 2013 08:41 AM	FYI, I just got of the phone with The Henry company's technical support (800-486-1278) who informed me that: 1. The Henry Company does not recommend using Henry 107 emulsion over spray polyurethane foam 2. They do not have UL or FM approvals of the product over spray polyurethane foam. The main problem of using a system that is not industry vetted, manufactured approved, has no manufacturer specification and application instructions, and does not meet building code requirements is that if something goes wrong with the system (even if it is not the fault of the coating), you can be sued and lose. This has happened frequently in Florida and other places. A good example is installing SPF roof over asphalt shingles. Our collective field history is very good in using foam over shingles, but it is not compliant with the ICC or Florida building codes. There have been recent situations that the foam contractor was sued for installing a non-code compliant roofing system and lost the case, thereby having to tear off the foam roof and the shingles then replace it with another system that was code compliant. As I was saying earlier there are many SPF/covering systems that provide great hail resistance and are code compliant. I would use those systems over a system that you feel is as good that does not provide the liability protection that you need. At the very least, talk to your local code official and ask for specific approval of the system. If he says it is OK then you have better legal protection. I doubt if I can persuade you to change a system that you feel is working fine, but, I am very concerned about the other folks who read my forum taking chances based on your comments. PS; The way to get the SPF industry to investigate the use of these type of coatings over foam is to write a letter to SPFA,'s Technical Committee (Staff, Rick Duncan). Explain in detail the system, how it is installed, the track record and offer a list of at least 5 roofs to inspect that are 5 years old or older. Get another contractor that is doing the same type of system to do the same. Also talk to your supplier and ask them to evaluate the system. As I mentioned, The Henry Company's official policy is not to recommend the coating over SPF but if you can provide them with a track record and history of successful applications, they may take you up on it and investigate it as well.
Tim Adams Posted: Jul 15, 2013 03:09 PM	Mason, First off, I didn't know this was your forum. Your carefulness is more easily understood after knowing that. Secondly, you hit on an important point that I missed. After 30 million sq ft installed, we know what works and what doesn't, but that doesn't mean everyone can make emulsion over foam work. I missed that important detail. I stand corrected. Lastly, I would risk throwing someone under the bus in order to make my Henry point. I don't want to do that; suffice that a buncha contractors in TX, AZ, and CA are installing emulsion over foam. They too are very experience contractor who know the risks ands manage the risks. Ok now a point on demographics. Texas loves its freedom and its frontiersman way of doing things. People around here tend to take the road less travelled, and they manage risk/liabilities but are not afraid of them to the point of being relegated to followers. Given your position in the industry and this forum, you are giving the absolute correct answers you should be giving, imo.
Jesse Michalski Posted: Nov 10, 2013 12:03 AM	Boyd. This is an interesting dialogue. I read about your interest in trying to prolong the lifespan of a coating over foam, and that you think 10 year recoats are a problem. Before I got into the foam industry, I spent a large portion of my construction career in commercial roofing applying Membrane roofs, namely EPDM and Tpo, with a little modified thrown in on occasion. I have done quite a few nice foam roof applications in the past few years. I have always adhered to using coatings that the manufacturer both supports and recommends for their system. Did you know that you can increase the mil thickness of your coatings and achieve a higher warranty period and extend the lifespan of the coating? Each year, U/v wears away several mils of coating. Why not just use a tried and true tested product with a good track record, and ifyou are wanting to give the client a better product, just put another 20 mil pass on the roof and you will have accomplished your goal, while protecting yourself and the industry... My father in law is a chemist and spent 25 years in a labratory developing paint coatings and urethanes. The lab is the place where new development should start, not experimenting with products in the field and seeing if it works. I agree with Mason not because he is the moderator, but because he has submitted himself to an industry standard, which is what true professionals do. If you have an inventive mind and think there is a better way, I encourage you in that, but stay humble in your perspective. Sometimes, the stop light works just fine, and the reason it is making you wait for 30 seconds is there is a bigger picture than just your schedule.
Tim Adams Posted: Nov 10, 2013 08:18 AM	KCfoam, I agree in principle. That said, very few roofing innovations began "in the lab." I can't think of any, except maybe for single ply systems, and they were simply modifications to membrane systems. That is true of nearly every industry. It is part of the American spirit of innovation to always try to build a better mousetrap. The mouse doesn't want a better mousetrap, and the engineer who makes his living off of the old mousetrap design doesn't want a new design either. I'd think those who make their living as experts in the foam industry, would be spending their time trying to develop coatings that don't need redone every 10 years, rather than trying to put the brakes on those who are trying to make foam roofs last longer than they do. It reeks of the Bill Gates Syndrome: If it wasn't invested here...
Jesse Michalski Posted: Nov 10, 2013 11:26 PM	Boyd. I really don't have a problem with inginuity. I have a folder in my office of 10-15 designs on everything from hydroelectric ideas to solar and wind upgrade ideas to help people realize an affordable way to get off the energy grid. I would love to test them and develop it. In a sense, tho, if I began testing the designs and concepts, it might not be a "official" lab, but the testing and documentation of the processes becomes a lab environment, even if it's in my garage or shop. I won't ever be guilty of trying to hold down a creative thinker. I just think that it should always be tempered with humility or caution... In the multitude of counsel, there is safety. It is possible to be innovative and still excercise wisdom as it relates to the customer, the industry, and your business. It's up to us to decide what that looks like. For me, I view it as wise to use approved, tested products and systems. That doesn't mean I wouldn't consider trying something out in my shop and setting it out in the sun for a few years to see if it works better. You aren't admitting innovative defeat if you bail on emulsion and stick with acrylic, even tho you know it needs a recoat down the road. It' simply says that you are going with what is approved for foam, and you keep thinking of a better way and devlop it if you think it's a good idea (and if you can afford to test your idea and produce data to support the claim) It would be nice if people would just develop a coating that lasted forever, or a car that didn't rust out in 8 years or need repairs, or a knife that never got dull, but good luck trying to turn around planned obsolescence, although I am still driving my Ford Powerstroke 7.3 with 240,000 miles. I'm sure at least a few jobs were lost on the repair side when they rolled that engine off the line. Perhaps some companies got it right. But then The Government regulated emissions and it was discontinued, and replaced with a weak distant cousin, the 6.0 liter. Buying that truck was like finding a scorpion in your shoe. I feel your pain about the moustrap thing. I've gone back and forth with the conspiracy theory that technology is suppressed and released in spoonfuls. Is there a better coating that has already been developed but is protected as intelectual property until the right opportunity comes along to make a lot of money on it? I wonder. Until I know for sure, I'm sticking with what I know works and has approval, even if I have to admit that it needs a recoat in 10-15 years.
Tim Adams Posted: Nov 12, 2013 04:58 PM	KC, agreed. My family has been "inventors" for decades. My dad has developed 10 or so roof systems. Speaking of solar, my son and I "invented" this solar roof drain and sold the company a couple of years ago: www.pondingpump.com
Tim Adams Posted: Nov 12, 2013 05:06 PM	Mason and the other experts are a very necessary part of the process. They take the goofy ideas people like me have, and prove them or disprove them so that they're ready for prime time.