Scorpion Spray Foam Insulation is a proud installer of metal building insulation. We strongly believe that every metal building needs proper installation of spray foam insulation for temperature control, pest control and overall building durability. Metal Construction News offered this article we think conveys the message exceptionally well. These are not projects to take on without an expert. Read on…

Spray polyurethane foam (SPF) is a premium building insulation utilized widely in structures of all types, including metal buildings. When applied in the walls, floors and ceiling, the material delivers numerous benefits including durability, energy efficiency and comfort.

When considering SPF for your metal building—whether a warehouse, agricultural or commercial facility, or even residence—be sure to review installation best practices to ensure the highest performance.

SPF Applications for Interior Metal Building Assemblies

SPF is an ideal solution for metal panel assemblies. Single-skin metal building assemblies are durable components of a building envelope, yet they offer no insulation. While other products can insulate the metal skins, they often fail to insulate structural members such as beams, rafters, purlins and girts. To address this, continuous air barriers, vapor retarders and insulation are needed. SPF is the only product that can provide these barriers in a single application.

SPF provides thermal, air, moisture and sound barriers, enhancing the interior comfort of the structure. These barriers protect against condensation and water damage, maintain indoor temperatures and humidity for dramatically reduced energy costs, and reduce the amount of allergens and pollutants able to enter the structure—a true benefit for those suffering from allergies.

As an insulation material, SPF is versatile, durable and lightweight. It can lend increased strength to the building envelope and once installed, requires no maintenance. Among its many benefits, SPF can be used in any climate. Insulation performance is properly assessed by reviewing the combination of air movement, moisture control, health, safety, durability, comfort and energy efficiency with SPF scoring high marks in all categories when applied in metal buildings.

SPF can be used to fill and seal cracks and gaps in the panel assemblies and dramatically minimize air leakage, however there are design parameters to consider. The Spray Polyurethane Foam Alliance (SPFA) and Metal Construction Association (MCA) technical bulletin, “Spray Polyurethane Foam Insulation on Interior Surfaces of Metal Panels,” provides guidance based on research conducted on the installation of SPF onto metal panels and is accessible via download at

Proper Foam Installation

While the benefits of SPF are immense, they are optimized with the safe and proper installation of the product. Because SPF is manufactured on-site during the installation, there are specific guidelines and measures that are mandatory to maximize product performance and to ensure safety for installers and facility users.

Equipment Care: The care of professional SPF installation equipment is imperative to ensure safety, proper installation and the optimum performance of SPF. Regular inspection, cleaning, repair, proper storage and maintenance are essential. Contractors should have a supply of spare parts in each rig to minimize downtime should equipment failure occur during installation.

Maintain Proper Temperatures: Spray foam chemicals must always be stored within the manufacturer’s suggested temperature range to protect shelf life and ensure application success. During installation, equipment should be set to the manufacturer-recommended temperatures and pressures to produce ideal SPF. Substrate and ambient temperature and relative humidity must be monitored as well.

Photos provided by MCN

Safety Precautions and Personal Protective Equipment (PPE): SPF is formed on the job site by mixing equal volumes of two liquid components. The A-component contains polymeric isocyanates (or pMDI), and the B-component is a proprietary blend of polyols, blowing agents, catalysts, fire retardants, and surfactants. Manufacturers of high-pressure SPF typically provide sets of A-component and B-component in 55-gallon drums.

Consideration must be made to protect against contact with liquid and airborne chemicals developed during and shortly after application. Protective measures must be employed to minimize risks associated with exposure through inhalation, skin and eye contact. These include spray zone containment, adequate ventilation during installation, safety training (for all involved in installation), use of personal protective equipment (PPE), such as fullbody suit and headsock covering skin, along with nitrile gloves and eye protection for full installation duration as well as a medical surveillance program for field crews. Respiratory protection for interior insulation requires the use of a supplied air respirator (SAR). Airborne chemicals disappear a few hours after spraying, so re-occupancy guidelines from the manufacturer must be followed.

Additionally, overspray from SPF insulation applications must be controlled to prevent it getting on unintended surfaces. Finished surfaces as well as window glass needs to be properly covered and masked to prevent overspray.

Photos provided by MCN

Surface Evaluation: SPF has excellent adhesion to most construction materials including metal. Existing surfaces must be dry and free of oils, grease, dirt and debris that could affect adhesion.

Assess weather conditions when applying spray foam. While SPF may be applied in numerous climatic conditions, manufacturer recommendations should always be followed. The spray foam and fire protective coatings should not be installed when ice, frost, surface moisture or visible dampness is present on the surface to be covered. SPFA’s guide for installers on surface evaluation for insulation applications (AY-112 “Spray Polyurethane Foam for Residential Building Envelope Insulation and Air Seal”) is a free download on the Technical page of

Selection of Appropriate SPF Products: A wide range of SPF products are available in various densities, each exhibiting different performance characteristics such as moisture resistance, R-value, and structural properties. In the case of metal buildings, closed-cell foam is typically used due to its moisture control and structural characteristics.

Preparation and Priming: In some SPF insulation installations, priming of the substrate surface may be required, especially when applying foam to metal surfaces as primers can greatly enhance adhesion between the SPF and metal substrates. SPFA has published a guidance document on selection and use of primers for SPF, AY-143 “Primers: Why, When and How to Use Them.” Prior to and during application, adhesion of the foam should be checked.

Installation of Protective Coatings and Coverings: SPF insulation must be separated from the interior space using a qualified 15-minute thermal barrier to provide code-compliant fire protection. While 1/2-inch gypsum in the walls and ceilings, or 3/4-inch plywood subfloor, prescriptively meets this requirement, other applications of foam may require application of an approved thermal barrier covering or coating. In limited access attics, an ignition barrier coating over the foam may also be required. Manufacturers provide a list of acceptable fire protective coatings in their product evaluation reports

Certification Matters

All guidance mentioned represents essential practices for the installation of SPF for insulation applications for metal panel assemblies. The best way to ensure best practices are followed is to utilize a professional, experienced SPF contractor. The SPFA’s ISO-compliant Professional Certification Program (PCP) is available to all professionals involved in SPF installation and allows the contractor to demonstrate knowledge, skills and abilities. Certified installers represent the industry’s leadership in spray foam installation and safety and have proven their ability to optimize the product’s ultimate performance.

Rick Duncan is the technical director of the Spray Polyurethane Foam Alliance (SPFA), the industry’s leading organization representing contractors, material and equipment manufacturers, distributors and industry consultants. The SPFA promotes best practices in the installation of spray foam and is an advocate for energy efficiency in the built environment.

If you’re ready to take on your metal building insulation project in Tulsa, Norman, Oklahoma City or Fayetteville, Fort Smith or Houston or Dallas, we’re the one call you need to make.

Let’s get started!

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