Spray Foam Part Two! Assuring Quality Spray Foam for Builders

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This article is a follow-up to an article published in the July issue of The Informer, and was contributed by Henri Fennell, a building envelope specialist and architect from North Thetford, VT.  Henri has over forty years of experience in energy conservation design, products, and services, and was one of the featured presenters at our recent IAQ & Energy 2018 Conference. We encourage Informer readers to visit Henri’s website for more information and resources on spray foam installations. www.polyurethanefoamconsulting.com. Videos of Henri’s presentations at IAQ & Energy are available at www.iaqandenergy.com.


When I was first asked to write this article my first thought was why would anyone want an article about the recent increase in foam failures, or, as I would put it, “problems” in projects that include spray foam insulation?  As one building science expert who inspects building envelope failures stated, “I’ve seen more foam failures in the last two years than I have seen in the last 25.”  The general answer to why this is occurring is that the use of foam has increased significantly in the last 5 to 6 years, and many new contractors are entering the industry to supply the need this has generated.  Unfortunately, the old model of new installers coming from established installation companies who have trained their technicians is no longer the norm.  Now, anyone who can buy the equipment and the chemical is a “qualified” installer, and the threshold for contracting with an installer is no longer quality based, but only requires the lowest bid, regardless of the qualifications or experience the installer has.  Many of these foam problems lead to occupant health issues.   Most of these issues are indoor air quality problems, caused by outgassing from misapplied foam.


How much foam are we installing?

How much growth is there in the foam market?  “The U.S. market for polyurethane foam used for building and construction has grown steadily since 2002. Professional contractors and consumers have increasingly purchased foam-based insulation products for a multitude of energy-saving renovation projects that could offset the rising cost of heating commercial and residential properties.  In 2004, 1.5 billion pounds of polyurethane foam was processed in the United States in the construction industry alone, with accelerating growth since then.  Demand is expected to increase by a global average of 9.8% per year between 2007 and 2012, creating a potential market of nearly 654,000 tons by 2012.”   In 2014 the US construction census showed that this had grown to 1.9 billion pounds.

“Global Polyurethane market to reach 9.6 million tons by 2015; Once again, rigid polyurethane foam products accounted for the largest share of the 6.5 billion lbs of polyurethane produced in NAFTA in 2008. The figure reflects the relative strength in demand for rigid polyurethane foam as an insulation material. The past two years have witnessed stable demand from the construction industry. New housing starts have declined, but expenditures on remodeling and repairs has increased. This development is partly responsible for the growing demand for spray and injected polyurethane foam as internal wall/roof insulation and the slower than expected decline in CASE products like elastomers used in thermal breaks in insulated windows, solar panels, wooden floor and turbine blade coatings, adhesives and sealants, and the steady demand for one-component spray foams.”


This increase in demand is driven by rising fuel prices and green initiatives.  It has also led to new performance-based energy codes and regulations, and when a poor economy hurts new home construction, people who are not buying new homes are upgrading the energy performance of their existing homes to save on energy costs.  In addition, local, state, national, and international code agencies are mandating verified airtightness levels that are well beyond what the industry has been used to.  Standards organizations like ASHRAE are tightening design standards and regulating building enclosure materials, assemblies, and mechanical systems.  Additional ASTM protocols have been created to verify the performance of building materials, assemblies, and buildings being renovated or constructed.  Green initiative programs have stimulated high-performance building concepts like net-zero-energy, Passivhaus, deep-energy retrofits and micro-load buildings have become main stream, and energy-efficiency programs like EPA Energy Star, LEED platinum, the Weatherization Assistance Program (WAP), and the 2005 Energy Policy Act have all stimulated the use of field-installed foam products.


It should be noted that this growth is not just due to economic and energy conservation circumstances.  Spray polyurethane foam (SPF) is uniquely qualified in the insulation industry in its ability to implement high-performance building envelopes.  While all insulation materials reduce heat flow due to conduction, open and closed-cell SPF also provide an integral air barrier.  Closed-cell foam provides insulation, air leakage control, vapor control, and can be an effective drainage plane (water management) material. Because of this combination of capabilities and the ability to handle vapor drive in two directions (winter-summer), some in the industry refer to closed-cell SPF as the “Perfect Wall” system.


So, why have there been so many foam problems lately?

This is not an easy question to answer as the answer must of necessity include a number of possible causes that exist throughout the construction industry.


Lack of Industry Standards

Despite the steady increase in the use of foam in the US over the last ten years, there are still no comprehensive US foam installation standards to provide guidelines or oversight for this segment of the polyurethane foam industry.  A uniform system for installer certifications will be part of the standards when they are in place, but the industry has needed an industry accepted certification program with an enforcement component for over twenty years.  Only organizations like The Air Barrier Association of America (ABAA) provide for-fee quality assurance programs, and the only certifications available are provided by an assortment of industry members, including equipment manufacturers, foam suppliers, and various training organizations with many levels of varying sophistication and competency.  These certifications are not consistent, often only including sections of the planning and installation process related to the training providers’ interests; i.e., equipment use, material use, safety, and generalized spray foam training.

Currently, it is left up to architects and consumers to regulate and mandate the minimum quality and performance requirements for foam installed in their projects.  Owners and design professionals must develop their own specifications or rely on high-end installers or specialists.  In order to ensure project quality and performance, consumers must be willing to pay more than the lowest price in a competitive bid situation.  This premium is either the cost of developing their own in-house standards and/or specifications to raise the bar on installer quality, hiring a third-party foam expert to oversee the work, or by hiring a well qualified contractor who has extensive experience and the associated overhead that goes along with in-house quality assurance protocols and the ability to guarantee his work.


What are the causes of foam problems?

The causes of foam problems typically fall into three major categories.  These generally include chemical, installation, and application/design defects or omissions.  Foam problems can result from design issues, improper product selections, lack of building science knowledge, bad or damaged chemicals, equipment problems, spray technique errors, improper substrate preparation, improper installation, improper environmental conditions during the foam installation, improper environmental conditions during the foam cure period, or improper maintenance of the environmental conditions the foam is exposed to after the installation has fully cured.  Only some of these are actually foam product quality issues, it is important to note the distinction between foam projects with problems and projects with foam failures.

ASTM or other laboratory tests performed under standard conditions do not necessarily emulate conditions installers may experience on site.  A hot summer day with black tar paper on the outside, the roof deck can reach temperatures of 180°. This condition will requires a different installation procedure than a 70° wall on the north side of the same house on the same day.  Installers can’t rely solely on generalized information in Installer Manuals or in Product Data Sheets to know when to adjust their work to the changing conditions and locations in which they work.  You have to understand what is behind the basic guidelines the manufacturer provides in order to adjust accordingly.  For example, most specify a minimum and maximum pass thickness, and some specify a maximum daily coverage.  Knowing why the pass thickness is limited and when core conditions will allow the next pass or a greater coverage depth, can prevent foam problems caused by a substrate that is too hot or an inappropriate pass thickness.  Understanding what the core temperature threshold is, and being able to measure it, are critical in determining if a pass thicknesses is too great, or when core conditions allow for improved productivity.  Assembly and performance problems can be the result of design errors, material choice errors, or the result of changes in environment.  A cold fall morning may indicate a winter formulation, while a hot afternoon the same day and a hot roof substrate may require switching to a summer formulation or using a pass thicknesses at or below the low end of the manufacturers recommended range with longer cooling periods between passes.


Foam Chemical Defects

Even products that have been around for a number of years can have problems.  Some manufacturers’ materials will vary slightly from lot to lot.  Some manufacturers make changes in the chemicals without notifying installers.  This can change how the foam processes and modifications that change the specific gravity of the A and B sides will affect readings in ratio monitoring equipment.  Even so, factory control of processing conditions and the quality assurance protocols in mass production equipment are far better than the small-scale production equipment found in field installations, so the likelihood of chemical problems is much lower than distribution and installer issues.  Nevertheless, there are a small number of documented foam problems that were traced back to foam chemical issues.  Manufacturers generally guard the information about these occurrences of quality control problems to reduce the impact on sales, and the manufacturing problems are usually quickly corrected and include support for the foam contractor in remediating related installations for the same reasons.

Some chemical problems don’t develop until after the foam chemicals leave the factory.  During shipping and storage, the chemicals must be maintained under conditions that will not damage the material.  As a contractor, I refused a number of winter shipments from various manufacturers that arrived at our dock at temperatures well below freezing.  In some cases, usually during swing periods of the year, the shipping papers did not indicate that the product should be kept above freezing while in transit, a protocol that was the shipper’s responsibility.  We requested this as a matter of course in our purchase orders, but this was not always an effective strategy.  In other situations, the shipping papers had been marked “Protect from freezing,” but the trucking company had let the material sit in trailers rather than keeping it in heated warehouses between legs of the transit to the foam contractor.  I have never seen a training program that addressed this issue, so most foam contractors do not measure the temperature of the material when a shipment arrives; therefore, most would not refuse a delivery that was likely to contain damaged material. Overheating can also be a problem.  Most closed-cell foam systems (2005 and newer) have blowing agents that can boil at temperatures that can easily be reached in storage or shipping scenarios.  Many shipments arrived at my facility in trucks that had sat in the sun for extended periods, resulting in over-pressurized drums with the ends bulged out to the point that they wouldn’t stand up.  Overheating can also occur in contractors’ trucks or trailers in transit or while at the job site.  Another cause of foam caused by chemical defects is the use of chemicals that are past their shelf life.  After the use-by date, some products require mixing to avoid separation of the chemicals, and some chemicals contain additives that deteriorate over time.


Installation Defects and/or Omissions

Installation problems fall into three general categories – problems with preparation, poor application and installation technique, and inadequate follow-up.   These problems are all the result of a lack of training and not adhering to best practice procedures, including quality assurance protocols.  The foam installer must be able to run a business, understand the chemistry, know all of the installation best practices, and have a solid in-house quality assurance program.  Many large commercial projects build these into the project specifications, but installers serving the residential market have no real requirements that ensure a good outcome.  While the General Contractor should not have to be responsible for foam processing temperatures, mix quality, or ratio, there are things they can do to ensure that they will get a quality installation.  Builders generally know how to oversee their tradesmen, but this is new, and most are unlikely to have the depth of knowledge to know when the foam installer is making a mistake.  Methods the General Contractor can use to assure a good project during the work is a topic for another article.


Application/design Defects or Omissions

While there has been a dramatic increase in the use of foam and a disproportionate increase in the frequency of foam installation problems, not all building envelope problems are foam related.  In addition to the foam contractor processing and installing the foam properly, foam contractors and the designers must know that they can only use this high-performance material in applications and assemblies that will not create serious building envelope problems.  High-performance building assemblies are more sensitive to interior and exterior environmental conditions and water infiltration because the assemblies generally are more air tight and have a lower drying potential.  This applies to all types of high-performance thermal envelope assemblies, no matter what type of insulation is used.  Tight, well-insulated construction is desirable in terms of energy use, but high-performance building envelopes put more pressure on designers and installers to pay attention to the building science implications of their work.

In addition to moisture and water problems resulting from unforeseen building science consequences of new assemblies, new materials being introduced to improve building performance can also result in compatibility issues.  For example, SPF does not adhere well to materials that contain polyethylene, polypropylene, or some chemical additives.  Originally, peel-and-stick membranes we now use for window and door openings and through-wall flashings had to be torched to make them compatible with SPF.  The major manufactures modified the polyethylene outer layer of the membranes so that foam would bond to the material and create a durable air barrier transitions.  Some A/V coatings and membranes are temperature sensitive and the heat of reaction of SPF can melt the bonding material, releasing the foam and the A/V material from the substrate.

Many designers (and contractors) do not understand how the physical properties of the foam materials relate to where and when those materials are best suited.  Open-cell foam, for example, should not be used below grade and should not be installed in a roof before the roof is weather tight.  Open-cell foam can take on water, and this dramatically affects its performance.  While open-cell foam may be able to dry out over time, the amount of time it takes to dry out depends on the environmental condition the foam is in.  If the foam is in a leaky roof cavity between plywood and a polyethylene vapor retarder that was installed the day after the foam was installed, it may never dry out.  Open-cell foam requires a vapor retarder in climates zones four or five and above.  Open and closed-cell foam both need vapor protection if they are in a location where there is a high vapor drive for an extended period of time. Generally, the drying potential of the assembly must exceed the wetting potential.  For example, if you have an indoor pool or greenhouse with foam insulation in the enclosure, the warm, humid indoor conditions will usually be constant for the life of the structure; therefore, the enclosure assemblies can never dry out unless there is a vapor-permeable exterior sheathing material on the outside.  This would allow the wall assembly to dry out during the seasonal cycle, but this would be a non-standard type of construction, designed to address the need for drying.  Typically, this would require a ventilated wall or roof design with no vapor impermeable materials on the outside toward the vent spaces.  This is just one example of the contractor needing to understand which environmental and assembly conditions require special preparation or protection of the foam material and the structure to avoid a building envelope failure.


Training and Certification

Given all of the issues I’ve touched on above that need to be understood to be a qualified foam installer, what about the new entries into the foam installation market?  Most new contractors who haven’t worked for years with experienced installers, haven’t had a chance to learn about the materials, installation, and building science related to the work they are going to provide.  You can’t just buy a proportioner and be effective in this industry, at least, not consistently.  A foam contractor is providing a service at the construction site that is normally a process that is performed in a controlled-environment factory with equipment that typically costs at least an order of magnitude more than their equipment.  Key to preventing foam problems is for installers to have an understanding of how to reliably process the material given the equipment and protocols at their disposal.  This must also include using industry-standard methods of verifying that the manufacturer’s processing and installation parameters are being met.

In addition, increased foam sales has encouraged many existing insulation contractors (glass fiber, cellulose, etc.) and other contractors in previously unrelated trades (masonry, paint, damp-proofing, carpentry, etc.) to diversify into installing field-applied foam and air/vapor (A/V) barrier coatings.  While new foam contractors historically have been experienced first or second tier installers who leave an established foam installation company and start their own business, the recent dramatic growth in the number of spray foam and sealant contractors has included a significant number of contractors from other trades or people seeking new career paths with little or no experience in foam processing, and many who lack experience in construction in general.

In addition, most new entries into the foam industry do not have a comprehensive working knowledge of the building science related to the implementation of insulation and A/V barriers in standard or high-performance building envelopes.  Many of the problem projects I inspect are related to design and application errors, rather than improper installations.

If the industry had established ANSI installation standards and licensing requirements, new contractors would not be able to work until they had received adequate training in all areas of the foam installation process, safety, quality assurance, and the related design and environmental considerations.  Without standards and contractor licensing, consumers have no basis on which to evaluate which contractors will perform the work in a competent manner.  If these standards included minimum equipment performance, verification/feedback, and fault protection systems, I predict that more than half of the current foam failure projects could be prevented.

To add to the lack of industry-recognized credentials, the “lowest bid wins” market persists, regardless of the installer’s experience, qualifications, and capabilities.


How do you select a good foam contractor?

Key contractor attributes

When choosing a foam contractor, besides the obvious check to verify that the contractor is financially stable, find out what types of training the foam installer has received. Ideally, this should include a general spray foam training program which includes an introduction to air barriers and building science, certification by the manufacture of their spray equipment, certification by their foam supplier, and trade organization training program certification. Most foam manufacturers claim to not want to sell to unqualified contractors that have not been through their in-house training programs, but I speak from experience when I say this is not always true, especially if the sales chain includes distributors.  Combined, these trainings should cover processing, material, and applications, but the evidence is that this is not enough in far too many cases.  Unfortunately, this will have to suffice until industry standards and a certification process are in place.   At least, having all three types of training will indicate that the foam installer is better prepared than another foam installer who has only one or two of them.

Definitely check references.  Don’t just ask the foam contractor for his standard list of preselected references.  Ask them for the name and number of the General Contractor on their largest project, even if it was a commercial building.  Large projects will show the weakest links in the installer’s quality chain.  Larger projects are more likely to have an architect and some mockup or submittal process that will have required them to prepare adequate documentation and to implement the requirements of the foam manufacturer’s installation instructions. In addition, they may have been through formal quality assurance program on this project.  Sprayers get tired, equipment gets dirty, out of date inventory tends to be used up, and it is unlikely that only the installer’s A-team will do the entire project, so the General Contractor will have seen the best and the worst the installer has to offer.  If there are a lot of projects to choose from, pick the one farthest from the base of the business.  These projects tend to have the least oversight, and the technicians who are staying in hotels or traveling long distances to the work site are more likely to cut corners if they are not well trained or they are not interested in a quality reputation for the installer company. They want to finish the work and get home as soon as possible.  The contractor is less likely to service these areas for another project, so they may be less concerned about follow-up.  Also asking what the largest project has been probably will give you an indication of how large a project the company can handle.  You can also ask the contractor what types of structures and applications he has installed. Make sure these include several projects for the type of work you will be doing on your project.

Asking a foam contractor if he has been bonded is another good way to qualify them.  If the contractor has been bonded on a commercial project, the surety has done enough of a background check to take on the risk of insuring the contractor’s work.

Also ask how long the installer has been installing foam, not insulation.  Many of the previously batt or cellulose-only insulation companies who have diversified into spray foam will say they have been in the insulation business for a long time, even if they just bought their first foam rig last week.  This won’t be an untruth, but it may be misleading with regards to their experience with spray foam.  Experience with other insulation products may be an advantage over other foam-only start-ups, but not a good reference for spray foam quality.

Finally, ask if they are ABAA (Air Barrier Association of America) certified.  Contractors who perform ABBA projects are required to have completed ABAA spray foam training, which includes a building science overview, and they are required to perform quality assurance protocols during the work.  Not all foam contractors who specialize in residential work will have this air barrier qualification as this is primarily a commercial application, so this is not necessarily a show stopper.  Use this as a decision maker if your research indicates that the two are otherwise equally qualified.


Clear work scope and submittals

Another key to contracting with a qualified installer is to provide a clear work scope as part of your pricing/bid process.  This should include a submittals requirement. While this may seem like a process that is only used for commercial work, it is in your best interest to have the proper documentation on file.  Telling the installer in advance that he will have to meet these requirements should scare away unqualified foam contractors who are new to the industry or do not have the proper insurance or safety and quality assurance programs in place.  Established foam installers will have this documentation in place, so it won’t be a hardship for them to send you this information.  Submittals should include the following:

  • SDS sheets
  • Product Data Sheets
  • ICC ESR or CCRR Evaluation Reports
  • Certificates Of Insurance (including specific coverage for foam installations and for pollution insurance)
  • A Written Safety Plan including an Air Quality Management Plan
  • A Quality Assurance Plan
  • Matching product (manufacturer) and labor (installer) warranties


Reviewing the documents supplied in advance of the contract award should provide an indication of how professional and qualified the contractor is.  If you usually plan to include a mockup in the project, include this in the submittals list.  Finding out the contractor or his product are not qualified at the mockup phase of the work is somewhat after the fact, but certainly better than finding out after half of the house/building is complete.  If you are not using a mockup, require test shots be submitted on a daily basis.  Check out the first one carefully, compare it to the sales samples the manufacturer’s salesman hands out, and use it as a bench mark for the subsequent test shots.  The samples don’t have to be large and you don’t have to keep them forever.  Mark them with the date and the area of the building they represent and take a picture for the project record.

If you have a refrigerator on the job site, put a standard size sample in a zip-lock baggy and keep it cold overnight – after the recommended cure time.  If you are in climate zones four and above, double the minimum cure time and then put them in the freezer overnight.  Cycle these through as they are submitted on a daily basis.  Note any change in size or shape in the samples, and if there is a change beyond what the manufacturer’s product data sheet indicates is acceptable, proceed with a more detailed quality assurance of the installation.  (Insert before and after pictures here of a calibrated sample that shrank overnight in the freezer)

Finally, slitting the skin of the foam after it has cured fully will verify if it has locked-in stresses that might result in thermal shock failures later during seasonal changes.


Other information that may help you to make a selection might include the following:

  • Unit pricing for a typical installation
  • Does the installer use both open and closed-cell foam?
  • Can they process slow-rise cavity-fill foam if there are closed cavities in the project? (this would indicate a broader experience and understanding of the basics)
  • The number, nature, and resolution of any major call backs (did the contractor stand behind his work and was the resolution acceptable to the client?)


Another resource for finding a good contractor and the right foam product for a given application is to use a professional who specializes in planning, development, and the quality assurance of air barrier and foam installations. These building envelope specialists usually are on the design team for high-performance commercial building projects, but there is no reason that they can’t provide their expertise to the residential market. It is their job to pre-qualify products and installers, verify that the details are scientifically correct, and make sure that the installations perform as specified. In some cases they may provide on-site quality assurance and/or air barrier compliance testing.


How you choose the right foam product?

The first decision is always closed-cell versus open-cell foam. If the foam has to provide vapor control, is exposed to bulk water, or if long-term exposure to high levels of vapor is critical to the project design, closed-cell foam is the best choice.  Long-term high indoor humidity, groundwater infiltration, or long-term exposure to bulk water typically indicates using closed-cell foam.  In extreme environments like pools and spas, even closed-cell foam will require additional vapor control measures (“don’t try this at home”).  Normal residential structures in a climate zone of four or greater would indicate closed-cell foam, or a combination of open-cell foam and an additional vapor retarder material capable of handling summer and winter vapor drive conditions.  If you’re spraying foam onto the inside of masonry that may perform as a rain screen and a drainage plane installation is not possible, closed-cell foam would be required to tolerate intermittent wetting.  If the masonry is not a rain screen, it is important to know if the masonry wall materials can tolerate insulation or if it needs to allow drying to the inside to prevent freeze-thaw, efflorescence, or spalling.  These decisions are generally best left to experts who can analyze the hygrometric performance of the wall.

If none of these moisture or water problems are issues, the size of the framing will usually dictate which type of foam to use.  Open-cell foam is usually less expensive than closed-cell foam for an equivalent R-value, but if you only have 2 x 6 rafters, you can’t meet current code and performance standards with open-cell foam because the per-unit R-value is too low.  If you have an existing building with 2 x 8 studs, you can use open-cell foam – with or without a vapor retarder, depending on the climate zone, and still meet or exceed code or energy program requirements.  If framing size does not dictate the choice, a simple calculation of the cost per unit of R-value will give you the most economic choice.  This can get tricky if you have 2 x 6 studs and the specification is for R-21.  This would require 5 1/2 inches of open-cell foam in a 5 1/2 inch framing member. With open-cell foam, this will probably require an average of 6 1/2 inches of foam to be sprayed in the framing to ensure full coverage/fill. The same R-value can be provided using closed-cell foam with only 2 1/2 to 3 inches of foam, depending on the specific product R-value per inch.  In this case, 3 inches of closed-cell in a 2 x 6, with no trimming and no waste, may be more cost effective than open-cell foam.  Obviously, in very deep roof framing members, open-cell foam will cost less than closed-cell foam because neither will require trimming.

Most polyurethane spray foam systems can be applied in normal environmental conditions that are encountered in the residential construction industry. The manufacturer’s Product Data Sheet provides guidelines on minimum and maximum installation and service temperatures. If they don’t, the foam contractors should be able to get the information from this supplier. None of the two-part polyurethane foam products on the market like to be sprayed on a wet substrate. Water is a blowing agent for polyurethane foams and that means that the foam against the wet surface will be over-blown by the moisture.  As a result, the foam will have a lower density, at least in the layer against the substrate. Extremely low density material against the substrate affects adhesion, and if there’s a lot of water on the surface, a larger cross-section of the foam will have a lower density. Lower density material is subject to shrinkage, especially in high temperature situations. So, if you spray against a wet roof, put up poly, sheet rock, and then the sun comes out, you’re likely to have problems. This is just one example, but generally a clean dry substrate is always recommended for any polyurethane foam application.

Another common question is what brand of foam is best.  Most commercially available foam products with at least a five-year tenure on the market will perform equally well. There will be slight variations in the recommended installation procedures and physical properties from product to product, but most will be in the same range.  All products sold in the market place for use in buildings meet the building codes.  Submittal documents can be used to verify this.  Most manufacturers have ICC-ES reports for specific applications.

Ultimately, most foam contractors decide what foam to buy based on price, delivery time, and “processability.”  Processability is that subjective factor that relates to a particular sprayer, his equipment, and how the product looks when he installs it in what I can only explain as “an easy ergonometric application.”  Some installers will just find it easier to make their work smooth with a particular product, so if the price is close they’ll stick with it.  R-values per inch do vary, so consider this when choosing a product if cavity space is limited.

Most high-end closed-cell foam products have seasonal formulations.  These are tailored to extreme cold or extreme heat conditions.  Some manufacturers even have spring/fall formulations for the swing seasons.  I generally favor products with at least winter and summer seasonal offerings as they reduce the compromises required in one-size-fits-all chemistries.  Open-cell, water-blown, light-density products are less prone to seasonal conditions and do not usually require seasonal formulations.

I generally recommend against trying new products, at least without pretesting the material somewhere other than in a client’s home.  Given the number of quality products on the market, why would a foam contractor want to try a new material?  Well, usually this is because the new product comes with an attractive price tag.  The problem with new products is that they may be tested according to industry standards in the laboratory, but they are not necessarily fully tested in the field where environmental conditions, installation techniques, and substrate conditions vary dramatically compared to laboratory test procedures and conditions.  I have seen a number of new products that were introduced in the summer look great until the first cold weather – then the problems began.  For example, in the early 90s, when CFCs were first banned by the EPA and non-CFC products were introduced, Boston Whaler lost several months of production due to this phenomena.  The new blowing agents in the flotation foam weren’t stable in cold conditions and the hulls of the original production run of boats collapsed when they were first exposed to the cold.  This happened with building insulation as well, but the Boston Whaler example was the most dramatic example of the impact of foam material that was not fully tested. If your installer suggests a new product to save money, make sure it is fully tested. It’s like new car models and new electronic technology.  Wait until it has been around for a year or two before you use your clients as guinea pigs.  A word of caution, a new product may be introduced by a long-time vendor.  You may have heard the manufacturer’s name for years, but the new product still may not be fully proven.  If you are not sure, inquire about the volume of that specific product/formulation that has been installed, rather than how long the manufacturer has been in business.

As a foam installer, before I would install a new product, I required a sample set of foam material from the vendor to test on substrates we typically spray foam onto, at various thicknesses, and at various temperatures.  After curing, these samples were exposed to high and low temperature regimens at high and low RH to rule out problems that might be caused by extreme winter or summer conditions.  From these tests we learned about substrate compatibility, in-place density, tolerance to heat and cold, and processability.  If my technicians didn’t like the way it “went on,” productivity would probably suffer.  It’s not just the material cost that is important, it is the installed cost per R-value.  So a competitively priced, user friendly, high-R-value product will usually be the best choice.  User friendly means good processability, a wide range of processing temperatures or seasonal formulations, and an adequate in-place density to maintain dimensional stability without an excessive penalty for processed yield.

I also required full documentation, including LEED submittal information, which was often important to the client.  It was surprising how many prospective new vendors were unable to provide the full complement of documentation.  This testing and qualification of products and applications was expensive.  Training and participation in trade organizations like ABAA were also expensive. This type of overhead is necessary to provide quality installations and is why the lowest price is not always the best value.



What does a really good-quality foam installation look like?


The following pictures show properly installed foam in various applications.

INSERT pictures and with captions and pointers identifying key elements of the installation.

The following pictures show poorly installed foam in various applications.

INSERT pictures and with captions and pointers identifying key elements of the installation.

The General Contractor can have his own quality assurance procedures for his subcontractors.

Typical contractor problems – stratification, plugged filters, heater problems (primary or hose), mixer restrictions, gun filters and check valves.

As a contractor, to address quality control of the pumping equipment, I purchased after-market flow meters and ratio monitoring systems that compared the A/B ratio and set off an alarm or turned off the pump when the manufacturer’s tolerance range was exceeded.  This basically guaranteed that the amount of foam leaving the gun was on ratio.  Some equipment manufacturers are now considering this as a standard equipment capability. We also weighed the drums or tanks before and after the work, as a backup check on how well the equipment was performing.  If a general contractor wants to rule out equipment-related processing problems, I would require my foam installer to have, use, and document product ratio.  It is my recommendation to the committee that is working on a suite of foam installation standards that this be mandated for all foam equipment manufacturers and installers.

Once foam has been installed in/on a structure and a problem becomes evident, it is common for the parties to jump to conclusions about who is at fault.  Before the lawyers begin filing law suits, it is important to clearly understand the problem and then determine its cause.  Post-installation analysis is a complex diagnostic process, requiring an understanding of the entire series of events beginning with the design of the installation, and ending with how the installation has performed and what the conditions in the building have been since the installation was completed.



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