Spray polyurethane foam (SPF) is a spray-applied plastic that can form a continuous insulation and air sealing barrier on walls, roofs, around corners, and on all contoured surfaces.
We create SPF by mixing and reacting unique liquid components at the job site.
The liquids react very quickly when combined. They then expand on contact to create foam that insulates, seals gaps, and can form moisture and vapour barriers.
Additionally, SPF insulation resists heat transfer extremely well, and it offers a highly effective solution in reducing unwanted air infiltration through cracks, seams, and joints.
Types of Spray Polyurethane Foam
For insulation and other specific purposes, there are three primary types of SPF that we use:
- - High Density: often used for exterior water proofing and roofing applications, concrete jacking, asbestos encapsulation.
- - Medium Density: often used for continuous building insulation, interior cavity fill, and unvented attic applications.
- - Low Density: often used for interior cavity fill and unvented attic applications.
Each product offers unique benefits that a professional SPF contractor can explain to you and help you determine which types of foam will be most appropriate for your building, climate, and project.
Beyond the structure of the foam itself, the other significant difference relates to how we create and install SPF.
High-density spray foam is an excellent choice for roofing or other exterior insulation. This is because of its seamless, monolithic nature, in addition to its thermal resistance properties.
In roofing applications, its thermal- and vapor-retarder qualities provide great benefit, while its strength provides load support.
High-density foam can help reduce energy costs significantly over a roof’s lifetime, while also offering high protection against heat and water infiltration.
It also strengthens the entire structure to which we apply SPF.
The bond that SPF forms to the roof can increase a building’s resistance to wind uplift, which can help reduce damage experienced during periods of high wind.
Medium-density foam offers specific benefits, depending on the climate and the type of building.
Like low-density foam, we often use medium-density SPF for:
- - continuous insulation,
- - interior cavity fill,
- - and unvented attic applications.
As a closed-cell spray foam, however, the application medium-density foam is where there is need for the greatest R-value insulation per inch possible, such as in tight spaces.
Medium-density foam can also provide a high tensile and bond strength.
Additionally, it can provide low vapor permeance and is typically not affected by moisture, such as wind-driven rains, in typical applications.
Low-density spray foam can be applied on walls, in unvented attics, ducts and ceilings, and in vented attics and crawl spaces.
It is impermeable to air, but permeable to moisture. We often use low-density SPF to fill cavities in walls during construction.
Due to its relatively large cell structure, low-density foam stays soft and flexible after curing.
This increases the likelihood of its continuing to provide high insulation value even as the building settles and shifts over time.
Low-density SPF provides effective heat insulation and seals air flow through cracks, joints and seams by filling the cavities.
In addition, this foam can absorb sound thanks to its soft texture and open-cell structure.