Product selection

Rebuilding after Sandy?  If you need to replace your wet cellulose or glass fiber insulation, closed-cell spray foam may be the solution for you!  More on product selection after this relevant news piece.

An innovative foam Hurricane Sandyproduct first introduced in 2007 allows you to have foam installed without a protective coating, while still safely meeting all building codes.  This spray-applied product, named One Step, is water resistant, has superior insulation properties, and provides air sealing and vapor control in one fast application.  One Step is installed using the same equipment and methods as standard spray foam products, but eliminates worries about burn out or pass thickness limitations common with other closed-cell foam systems.

FEMA: Dealing With Mold & Mildew In Your Flood Damaged Home

“Rebuild, or retrofit, with water-resistant building materials such as tiles, stone, deep-sealed concrete, galvanized or stainless steel hardware, indoor/ outdoor carpeting, waterproof wallboard, water-resistant glues, and so on.”

Insulate now with One Step to keep your home warm, install gypsum board later.  No concerns about leaving foam exposed for extended periods during reconstruction.  One Step has been fully tested and has been used in many high-profile projects.  More information about the uses of One Step are available on the Preferred Solutions, Inc. (PSI) web site at:  Project profiles, technical data, and material safety information are there as well.

As a building envelope commissioning agent, I like to specify the One Step product because it eliminates having to know which protection barrier will be approved by the local AHJ, and what the required special inspections (IBC 1705.3 and 1705.6) will cost.  And most important, unless you are using gypsum board as the finish so that cost is already built in, One Step always costs less than the combination of other foam products plus any other barrier coating.  It also has productivity and quality assurance advantages that make my material and performance inspections easier.


First we need to understand what is out there.  There are four basic types of “polyurethane” field-processed materials that could be involved in creating a complete air barrier system or building enclosure.  These generally include foams used for insulation, air sealing, vapor control, water management, and for enhancing the structural integrity of building assemblies.  I’ll do my best to summarize the materials and their typical uses.

  1. Urethane caulking: this is a single-component sealant, is not a “foamed” product, comes in a tube for use with a caulking gun, and would be used for small cracks (1/8″ or less), including the seams of exterior sheathing as an alternate to air barrier membranes (Tyvek, etc.).  Urethane caulk stays resilient and sticks to most common substrates.  It is frequently also used as an adhesive.
  2. Single-component polyurethane foam sealants: this class of “foamed” materials is typically used in small quantities for sealing cracks and gaps too large for caulking, around window and door rough openings, pipe and wiring penetrations, etc.  These products come in expanding and low-expansion formulas and are very controllable, which makes them attractive for detailed air sealing work.  The formulas are relatively low-density with a low R-value and are vapor permeable.  They come in disposable aerosol cans or in disposable cylinders that screw onto a re-usable portable gun.  (Examples: Great Stuff, Todol Pur-Fill, Zero-Draft).  Single-component polyurethane foam sealants are commonly used in new construction and weatherization work.
  3. Two-component polyurethane foam insulation/sealant in “portable” or “disposable” kit systems.  This type of foam comes in various size pressurized containers complete with a set of plastic hoses and a gun for the professional or the do-it-yourselfer.  Due to their size and portability, these kits are used in remote locations or for small projects where full-scale equipment is not cost-effective.  Optional spray-applied and slow-rise formulations can be used for air sealing or insulation.  The in-place density and closed-cell content of these low-pressure products are both higher than the single-component foams; therefore, the physical properties of these products are getting closer to the “real” machine-processed high-pressure polyurethane foams.  Again, the cost of the material is relatively high ranging from $5 to $10 per pound.  At this lower level of material use, the OSHA requirement for personal protection equipment kicks in. (Examples: Instafoam Froth Paks, Handi Foam, Zero-Draft, Tiger Foam, etc.).  Note: I have tried a number of single-component “portable” or “disposable” kit systems over the past 30 years.  In my experience, none of them has reliably processed correctly.
  4. High-pressure spray-applied polyurethane foam (SPF) and injected polyurethane foam (IPF) insulation / sealant systems are materials processed through high-tech bulk processing equipment.  Formulations are available that can be processed in a variety of densities and R-values at much higher rates than with any type of portable equipment discussed above.  Raw materials’ costs range from $2 to $3 per pound.  Closed-cell formulations have high R-values, low air and vapor permeability, and are stronger than lower-density products.   Open-cell polyurethanes provide air sealing and insulation, but are not used for vapor control or in locations where water tolerance is necessary.


Now that we know what is out there, which product should we use?  As a recognized member of the foam industry for quite a few years, I am frequently asked by architects and owners “which foam brand or product is the best” for their project; and, “who should I have install it?”  Responding to these questions raises concerns about recommending any one polyurethane foam product as there are a number of quality products on the market, and one type of foam is not the most appropriate for all applications.  The same is true for installers.  Some contractors specialize in certain types of work or have contractual agreements with manufacturers to install only one product.  Again, the best installer for one project may not be the best for another.

To address this question in a systematic way, a database of information about the foam products and installers that are currently serving the market place was created and is being maintained, primarily on a project-by-project basis.  A computer application that can query this data was developed to provide the means of matching and ranking the best-fit foam systems for specific applications.  (For information about matching products with qualified installers, click here).  This “Pre-Q Database Application” was designed to identify products that can be processed consistently, have the necessary documentation, are code compliant, are compatible with the rest of the construction, are durable, and will perform as specified for the normal life of a specific installation.  The Pre-Q program matches the attributes of the products to the criteria for each specific project.  Matches are based on the following information about the product and the project:

Product attributes

  • Processing requirements
  • Documentation
  • Substrate and environmental compatibility
  • Equipment requirements
  • Formulations/Chemistry
  • Installation method (spray, inject, etc.)
  • Installation requirements
  • Manufacturer-approved applications
  • Manufacturer-approved construction types
  • Manufacturer-approved uses
  • Manufacturer support
  • Physical properties
  • Pricing
  • Shipping and handling requirements
  • Safety requirements

Project criteria to match

  • Application – Building Use
  • Project goals – overall
  • Building enclosure details
  • Component function
  • Enclosure components
  • Enclosure component performance goals
  • Environmental conditions
  • Installation method (each enclosure component)
  • Location/access
  • Product preferences
  • Type of construction
  • Scope of the work
  • Substrate material (each enclosure component)