Spray Foam Insulation

Spray 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. It is made by mixing and reacting unique liquid components at the job site to create foam. The liquids react very quickly when mixed, expanding on contact to create foam that insulates, seals gaps, and can form moisture and vapor barriers. SPF insulation is known to resist 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

There are three primary types of SPF that can be used for insulation and other specific purposes:

High Density: often used for exterior and roofing applications 3 lbs./cubic ft., closed-cell foam

As its name implies, this foam has a denser structure than either of the other SPF types. Therefore, it does not expand as much as lower density foams and requires more material to cover and insulate any given space.This spray foam is an excellent choice for roofing or otherexterior insulation because of its seamless, monolithic nature, in addition to its thermal resistance properties. In roofingapplications, 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 it is applied. 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: often used for continuous insulation, interior cavity fill, and unvented attic applications 2 lbs./cubic ft., closed-cell foam

Low Density: often used for interior cavity fill and unvented attic applications 0.5 lbs./cubic ft., open-cell foam

Also known as open-cell-foam low density spray polyurethane foam is applied as a sprayed coating to provide a continuous insulation and an air-sealing barrier. The foam’s open-cell structure gives flexibility to the hardened foam. Low density SPF is also called ½-pound foam, as it weighs almost 0.5 lbs. per cubic foot.
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 insulationand 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.

Spray foam helps minimize air-borne sound transmission. Open-cell foam can reduce high frequency noise, and closed-cell foam can reduce low-frequency noise. A combination of open- and closed-cell foams can help maximize noise reduction.

Open cell spray foam costs roughly $0.80 per board foot to insulate a 2×4 wall. The walls are overfilled with foam and then shaved flush during installation to maximize thermal resistance. This means that some material must be wasted, which will effect the final cost.

Closed cell spray foam costs from $1.20 to $1.50 per board foot. To reach thermal resistance rating of R20, it needs less than the full depth available in any 2×4 wall cavity, meaning that no material will be be wasted. It’s more expensive because it acts as a vapour barrier, which eliminates the need for a polyethylene sheet.

These materials can survive wetting and drying and may be successfully cleaned after a flood to render them free of most harmful pollutants. In addition, spray foam prevents moisture and condensation throughout the building envelope, thereby helping to prevent the growth of mold and mildew. Applying closed-cell spray foam in the cavities of the walls increases durability of the wall system because of the foam’s ability to mold and adhere to the surface. upon which it is sprayed.