Thermal insulation for roofs and ceilings 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.

Vapor barrier and insulation in one product

The structures do not require separate air or vapor barriers. 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 sealing foam and vapor barrier or aluminum tape that is suitable for joints.

FF-PIR AL and PL insulation products are excellently suited for use with the different frame materials of roofs and various roof types. The frames can consist of wood, steel, concrete or lightweight concrete (Siporex), and the roof type can be sloping, low pitch or flat. The FF-PIR insulation products also provide an easy option for creating energy efficient structures with lattice trusses.

Roof insulation is chosen according to the roof structure

In a timber framed roof, FF-PIR insulation products can also be used as an interior vapor barrier layer, in which case the panels are covered with the amount of mineral wool necessary to achieve the desired U value. This type of solution is very common and cost effective where the roof is constructed with trusses.

If the entire structure is constructed from FF-PIR insulation products, 100 or 150 mm FF-PIR K600 panels, for example, are laid in between the roof supports. In addition to this, a second, continuous layer of panels is installed on the interior or exterior side of the structure. The thickness of insulation is determined according to the desired U value. If the insulation layer can be installed as a continuous layer on top of the load-bearing structure, the required U value of 0.09 can be achieved using a single layer of 240 mm or two layers of 120 mm FF-PIR panels.

The below table includes a few structure examples.