Expanding spray foam insulation is made of polyurethane or acrylic latex. The foam has been used in refrigerators and water heaters for many years.

Liquid polyurethane is pressurized and released through spray nozzles. When the spray lands on surfaces it expands and foams up, then hardens to a aerated material. Traditional insulation such as cellulose wool or spun fiberglass leave gaps and voids when applied as ceiling and wall insulation. Expanding spray foam insulation fills out to all cracks and into seams even if they are hidden from view. The sealing ability can practically eliminate air flow and energy transfer.

The resulting expanded polyurethane foam has a high R-value, which is the measure of resistance to energy flow relative to its thickness, when compared to other insulation materials. This high R-value feature can allow 4″ wall construction to achieve the same energy rating as a 6″ wall, providing improved performance at a substantial savings in construction materials and even increased floor area.

Because expanding spray foam insulation is dimensionally stable it does not settle or compress, and maintains its high performance characteristics. It does not absorb or transfer moisture, preventing humidity, condensation, and mold problems. It is also insect and flame resistant.

Although there are retail products for small crack filling tasks, expanding spray foam insulation for large areas is best left to professionally trained contractors who have the necessary equipment and expertise to apply this material effectively and economically.

There are hazardous materials handling issues when the polyurethane is in the liquid and aerosol state that require special precautions. Proper application and cavity filling requires experience and care to achieve the desired outcome and prevent damage or distortion of structural elements by over-expansion.

Coordination with plumbing and electrical installation is critical since the foam insulation encloses these utilities and makes it difficult to change or reinstall.

Expanding foam insulation costs about three times more than traditional materials to install initially. Some of this cost will be offset by savings in other areas and materials as mentioned above. However the longterm payback is increased energy savings year after year, with improved comfort and air quality, that justifies the investment in using expanding spray foam insulation.

Homes built prior to 1960 had no insulation or at best R-5. Between 1960 and 1980’s average R values increased to about R-11.

Insulating wall cavities that were empty or under-insulated will save energy. A 2″ x 4″ stud framed wall filled with expanding foam insulation will provide an insulating value of R-22.

Before insulating side walls you need to find out what is in there. Visual inspection through openings may reveal what is already in place, if anything, or an infrared thermal imaging will reveal heat loss in areas that are hidden or have varying insulating value.

Sometimes cellulose, fiberglass, or rock wool may have been blown in, and either not installed at the proper density or settled and lost effectiveness.

Adding insulation to partially filled wall cavities is difficult and a job for a well-qualified installer. Expanding foam insulation may be the best solution when done correctly. Beware of old knob-and-tube wiring because of the possibility of creating a fire hazard. Be sure to check with a licensed electrician.

If you are replacing exterior siding, it may be a good time to add insulation. Installing rigid board under new siding may not be the most cost effective method and complicates window and door opening depths and sills. Injecting expanding foam wall insulation could be your best choice and not require modifying window sills and trim.

If exterior walls are opened for remodeling consider in place expanding spray foam insulation for best R-value and reduced air infiltration.
Technicians with special equipment can test your house for air leakage. This test measures the air leakage of your structure at all localities and can reveal where hidden air flow occurs around framing, wall penetrations for plumbing and wiring, and chimneys and attic access.

Insulating wall cavities not only saves energy, but also improves comfort in winter and summer, drafts are reduced, and your home will be quieter with expanding foam wall insulation.

There are many benefits to this form of insulation over traditional materials. These benefits include ease of installation and durability.

Ease of Installation
The chemical resin can be sprayed in liquid form onto the desired area without measuring, cutting, or fasteners. It adheres to practically everything used in typical house construction such as concrete, masonry, wood, and metal. Application is fast and simple.

Durability
Expanding foam insulation lasts longer than previously used materials. It maintains its effectiveness longer with resistance to breakdown, compression, moisture absorption, or attack by critters.

Since it is unaffected by moisture it also is practically impervious to mold even in damp areas. Because it is inorganic it is not attractive to animals and insects for eating, gnawing, or nesting.

The inorganic compounds are non-polluting and benign to the environment. The effectiveness of using expanding foam insulation improves the air quality of your enclosed spaces by preventing infiltration of exterior pollutants from entering.

The biggest benefit of using expanding foam for insulation and sealing is the reduction of energy transfer. Thermal resistance reduces conductivity, and sealing gaps and cracks reduces air convection. Overall energy savings are considerable and make it cost effective to use expanding foam insulation.

The contemporary best practice is expanding spray foam insulation installation. Foam fills the cavities in between the framing studs of the walls and attic. Spray-on foam expands to fills in air gaps, unlike standard fiberglass insulation, which lets air pass through and around it. Even as a house expands and contracts the foam insulation expands and compresses with it. This prevents warm air from escaping through cracks and spaces.

A professional installer has the equipment to cover large areas quickly so that it is more cost effective than doing it yourself, but for small areas and sealing cracks you may choose to do it yourself. For a large space being installed with expanding spray foam insulation, the liquid to sprayed evenly between studs on the inside of the exterior sheathing. The material quickly expands 100 times its volume to fill all the gaps in the stud wall or rafter space. After the foam has set a handsaw is used to smooth off the excess from the framing. The wall or ceiling is now ready for drywall installation.

A better air-tight envelope is achieved by using expanding spray foam insulation in the walls and attic. The foam is non-toxic, high R-value, moisture-proof, fire resistant, and sound damping.

There are different products for different purposes. It is important to find the matching product for your job. These products generally come in handy sized cans and are easy to use.

Here is a list of typical special purpose expanding foam insulation products. Check the labeling to determine if the product is designed for interior or exterior use, toxicity to animals and plants, cleanup, and storage.

Acrylic/Latex Foam Sealant

Paintable
Clean up with soap and water
Low expansion
Reusable dispensing
Interior use

Minimal Expansion Sealant

Seal small cracks and gaps
Insulate against energy loss

High Expansion Sealant

Fill larger holes and gaps
Block insects and pests

Window & Door Sealant

Seal around window or door frames
Low pressure to not bow

Exterior Filler and/or Adhesive

Adhesive for landscaping projects
Direct water flow in and around water gardens
Fill decorative planters for artificial arrangements

Fire Block Foam Sealant

Fill and seal fire service penetrations
Retard fire and/or resist flame

As you can see from this list, there are many choices that give you the right product for your expanding foam insulation and sealing application. Wear protection eyewear and clothing for safety and easy cleanup whenever you use expanding foam insulation.

Insulation in the roof and walls is clearly beneficial for its ability to reduce heating and cooling losses and costs. The savings achieved by reducing heat transfer by conduction justifies the cost of adequate insulation.

But don’t forget that convection is another source of heat transfer when air moves between two spaces. Minimizing or controlling losses via convection is desirable but requires more consideration. Adequate outside air is necessary for breathing, and sufficient air transfer is required to ventilate other gases and odors from interior spaces.

Most homes are so leaky that there is plenty of opportunity for air to intrude and be enough for the occupants. However, as structures become more air-tight and interior materials become more synthetic, there is the possibility that the indoor air quality is compromised.

Controlling infiltration of outside air is important. Not only is uncontrolled air infiltration wasteful of energy it can also carry outside pollutants such as fumes and dust. Inadequate exhaust of indoor pollutants can cause allergies, respiratory distress and ’sick building syndrome’.

Expanding foam insulation applied to walls and roof voids fills small spaces and gaps that allow air to flow between the interior of a home and the outside environment. Eliminating these gaps prevents air convection from carrying heat between the interior and exterior of a home, which results in lowering the expense of heating or cooling a space.

Minimizing air from entering from the outside into the house means that expanding foam insulation can improve the quality of air inside your house. With proper permeable filters and especially electrostatic filters installed with your air-handler, circulating inside air can be controlled and cleaned of allergens, particulates and pollutants within a building’s interior. By using expanding foam insulation to reduce infiltration of outside contaminates, the inside air is a higher quality. This may be an even more important consideration if a resident suffers from allergies or respiratory conditions.

A more sophisticated installation that is used in commercial buildings and may be justifiable in homes is the use of an ‘economizer’ air handling system. By using an arrangement of ducts and dampers in an ‘H’ pattern outside air and exhaust air can be controlled to allow recirculation and proper ventilation. Depending on the sensible heat and latent heat outside, controllers move the dampers to allow the desired air flow in and out of the building space, which maintains adequate fresh air and takes advantage of the energy of the exterior for cooling or heating. This is especially effective for ‘air-tight’ structures and locations where day and night time temperatures and humidity vary significantly.

Expanding foam insulation is extremely useful to address multiple issues of conduction and convection. Whether it is maintaining the temperature of a home, controlling air infiltration, soundproofing a space, and minimizing energy consumption, almost everyone will enjoy the benefits of expanding foam insulation.

Fire resistant foam insulation contains fire retardant, and some are specifically formulated for fire resistant use.  If you need a fire resistant foam for insulation, be sure to choose one specifically marketed as such.  These products possess a higher degree of fire resistance than standard foam insulation.

Fire Resistant Applications include :
- fire resistant installation of window and door frames
- fire and smoke resistant sealing of connections between walls, ceilings and floors
- sealing of all openings in roof constructions
- sealing of cable and pipe penetrations in walls
- improving thermal insulation in heating and cooling systems

Soudal makes a fire proofing single component PU Foam with non-hazardous propellant and high adhesion to many building materials. SOUDAFOAM FR with CFC-free propellant is a one-component, self expanding, ready to use polyurethane foam with propellants which are completely harmless to the ozone layer. It has a fire rating of up to 229 minutes (4 hours) according to the new European Norm CE 1366-4.

Touch ‘n Seal makes foam sealant and insulating products that contain fire retardants. These foams are intended to resist flaming, and slow flame spread.  However, they cannot stop a fire from spreading indefinitely. Touch ‘n Seal foam is flammable and a fire hazard during dispensing. Do not use around fire or flame, and be sure to extinguish all pilot lights in the area.

ELCH PRO Fire Rated group contains four specialized products for domestic and commercial building applications. FR Silicone and FR Intumescent Acrylic sealants are both tested to BS 476:part 20 and fire rated to 4 hours. FR Acoustic Sealant is also sound tested to a value of 55dBA and is supplied in large volume packs. FR Polyurethane B1 Foam is fire rated between firm, mineral construction substrates and in this application meets the requirements of building material class B1 according to DIN 4102 part 1.

Froth-Pak, although combustible, has a European Class B2 or new Class E fire rating which is equivalent to BS EN11925-2, making it difficult to ignite. The foam’s low thermal conductivity makes it approximately twice as effective as an insulation material as other forms of insulation such as glass fiber, expanded polystyrene and mineral wool.

There are several manufacturers of fire resistant foam insulation products. Be sure to check their fire retardant properties and fire rating specifications so that they suit your purpose.

Garage insulation may seem optional, when other more obvious home improvements vie for limited dollars. But with rising fuel costs, it’s a good idea to take a close look at all the ways it could make good sense, and good cents, to insulate all or part of the garage.

This is particularly true for the attached garage. Insulation of common walls shared by the garage and the main living space is obviously of great importance. This includes the ceiling of the garage if there is living space above. All too often, there is great heat loss or gain through these walls, because the air in the garage can rise or fall to temperatures that are even more extreme than those outside. It is therefore almost more important to insulate the walls between the garage and the house as it is to insulate the house’s exterior walls.

Other reasons to insulate these walls include sound proofing, especially if the garage is ever used as a workshop. Perhaps the garage will someday provide a safe place to set up a generator for times when the power goes out. By opening the garage door wide and placing the generator in a safe position, adequate ventilation can be arranged, and the sound barrier between garage and home would be much appreciated by occupants of the house. Maybe the garage will someday serve as a practice room for the budding rock musician in your family, young or old. Or maybe it’s where you will lock the barking dog.

Proper insulation between the house and garage also serves a safety function, making it less likely that fire or fumes will spread between the two spaces.

A thorough evaluation of the insulation or lack of insulation in such walls should include careful examination to see if there are any holes between living and garage spaces, and whether the spaces around the doors are airtight.

Next, consider the reasons to insulate the exterior garage walls, including the roof, if there is no living space above. Insulating these exterior walls makes the temperatures inside the garage less extreme. This adds to the effectiveness of the insulation barrier between the house and garage and it also keeps the contents of the garage in a better temperature range.

Now, let’s consider the unattached garage. If you live in a cold climate and store your car in the garage, good insulation means your car will not be as exposed to the kinds of temperatures that can make it difficult to start in the morning. Conversely, if you keep your car in the garage in a hot climate, good insulation will mean your car will not have to endure such extreme temperatures. Nor will you, when you enter it.

If you use your unattached garage for storage or as a work area, the effect of insulation on your comfort and on the items you store will be beneficial. And if you heat or cool the garage for these purposes, then your energy bills will be that much less with good insulation.

It may be tempting to consider DIY spray insulation, especially if you decide to insulate only a small area. Keep in mind how quick and easy expanding foam insulation can be, especially if you already have finished walls in the garage, or if you will be insulating the ceiling. It’s definitely worth talking with a spray foam insulation contractor when you consider all your options for how to best complete your garage insulation project.