Thermal insulation for exterior walls using FF-PIR polyurethane insulation products

FF-PIR is one of the most effective widely used thermal insulation materials in the market, and its declared thermal conductivity λD is 0.022 W/mK. FF-PIR insulation products are suitable for new construction, low-energy, passive, and zero-energy construction, as well as for supplementary thermal insulation for older buildings.

FF-PIR insulation can be used to create very thin and leak-proof structures. In constructing low energy, passive or zero-energy houses, structural thicknesses will barely increase when compared to conventional houses built using traditional insulation products.

Combination of insulation and vapor barrier

Separate air or vapor barriers are also not necessary in the structures. The aluminum or plastic laminate on the surface of the FF-PIR insulation products has a very high water vapor resistance and also functions as vapor barrier within structures. For the seams and joints between the panels, we recommend using elastic foam sealant and vapor barrier or aluminum tape that is suitable for joints.

FF-PIR insulation products are excellently suited for use with different frame materials in roofs. The frames can consist of wood, steel, concrete or lightweight concrete (Siporex).

FF-PIR insulation products are suitable for all frame structures

FF-PIR insulation products can be used in exterior walls with various framework materials. When the framework is made from wood, the structure can be constructed as a so-called full PIR wall, where a 100 or 150 mm FF-PIR K600 panel is installed between studs with on-center spacing of 600 mm (K600). A second continuous layer of panels is installed on the inside or outside of the structure. If the second layer is installed on the inside, its thickness may be chosen freely based on suitability (30–150 mm). Where the second layer is installed on the outside of a load-bearing framework, the exterior insulation must be as thick or thicker as the FF-PIR insulation in between the framework elements to insure proper moisture performance.

Insulation thickness based on the U value

In a so-called hybrid structure, wind-proofing is installed on the outside of the studs in a regular manner, a mineral wool insulation is placed between the studs, and a continuous layer of FF-PIR insulation panels is installed on the inside, the seals seamed with elastic foam sealant and tape. The thickness of insulation is determined according to the desired U value. This will create an absolutely leak-proof and energy efficient structure.

The framework of the exterior wall can also consist of concrete, brick or breeze block, in which case the insulation panels are installed as a continuous layer on the outside of the internal framework.

The below table includes a few examples of wall structures.

Framework	Insulation/framework	FF-PIR	u-value W/m2K
Wood	FF-PIR 50 mm + on the inside 50 mm wool	FF-PIR 70 mm on the outside	0,17
Wood	FF-PIR 70 mm + on the inside 50 mm wool	FF-PIR 100 mm on the outside	0,13
Wood	FF-PIR 100 mm + on the inside 50 mm wool	FF-PIR 100 mm on the outside	0,11
Wood	FF-PIR 100 mm + on the inside 50 mm wool	FF-PIR 150 mm on the outside	0,09

Concrete element with insulation in between		FF-PIR 140 mm	0,17

Concrete element, ventilated exterior face		FF-PIR 140 mm	0,16

Concrete element with insulation in between		FF-PIR 180 mm	0,14

Brick	Full-brick cunstruction	FF-PIR 130 mm	0,16
Brick	Full-brick construction	FF-PIR 170 mm	0,13

Wood	Mineral wool 150 mm	FF-PIR 30 mm on the inside	0,17
Wood	Mineral wool 150 mm	FF-PIR 40 mm on the inside	0,16
Wood	Mineral wool 200 mm	FF-PIR 30 mm on the inside	0,14
Wood	Mineral wool 150 mm	FF-PIR 80 mm on the inside	0,12