Using FF-EPS insulation as thermal insulation for roofs

Designed for insulating roofs, FF-EPS is highly cost effective and safe in terms of moisture performance, with a declared thermal conductivity λD of 0.031 W/mK. FF-EPS insulation products are suitable for new construction, low-energy, passive, and zero-energy construction, as well as for renovation and supplementary thermal insulation of older buildings.

FF-EPS 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). Structures that are thermally insulated with FF-EPS always require a separate air or vapor barrier layer, as the product does not have a high enough water vapor resistance to function as vapor barrier on its own. The vapor barrier can be constructed using Finnfoam or FF-PIR thermal insulation products or traditional membrane-type vapor barrier solutions. The locking tongue and groove profile of the FF-EPS panels provides an easy way to ensure that the thermal insulation is continuous and leak-proof. The locking tongue and groove joints do not require the use of a PU foam, but any lead-throughs must still be sealed with an elastic PU foam sealant.

Insulation solutions are determined according to the roof structure

The FF-EPS insulation products are compatible with all commonly used roof framework materials. FF-EPS is a highly cost-effective thermal insulation material for flat and sloped roofs. For example, a U value of 0.09, which is the current requirement for roofs, is achieved with a structure consisting of a hollow-core slab, vapor barrier, FF-EPS M or FF-EPS X 60S/320 mm, 20 mm bearing layer of wool, and roofing. This construction ensures that the overall thickness of the structure remains at a reasonable level and eliminates the tracking risk on the roof even around access points. Today, a significant number of technological devices are placed on roofs, which require moving about on the roof, and thus the thermal insulation materials used on flat roofs must be able to withstand this stress without tracking. The sturdy thermal insulation products manufactured by Finnfoam Oy (Finnfoam, FF-EPS, FF-PIR) eliminate the tracking risk.

 

NEW FF-EPS 60S X SILENT!

 

At the end of 2019, Finnfoam ​​​​​​will begin deliveries of the new FF-EPS 60S X SILENT panel! The panels are coated on one side with a 15–20 mm thick special layer, which has excellent soundproofing and fire resistance properties and is suitable for use as a base for roofing. The FF-EPS 60S X SILENT panels have a 10 mm deep grid pattern below the coating, which is intended to function as a network of ventilation channels on low pitch roofs. FF-EPS 60S X SILENT reduces the cubic amount of material lifted on to the roof and allows for faster installation. The required U value of 0.09 can be achieved with a single 320-mm thick panel, which allows for faster roof construction.

 

 

Sloping timber structures

For sloping timber structures, the most effective roof solution with minimal thermal bridging can be achieved if the FF-EPS insulation can be installed as a continuous layer on top of the load-bearing structure. With glued laminated beams, it is also possible to utilize a structure where Finnfoam or FF-PIR panels are installed on the bottom surface of the joists as a vapor barrier, and FF-EPS panels with the thickness required to reach the desired U value are foam sealed in between the joists.

 

The thickness of insulation is determined according to the desired U value. The below table includes a few structure examples.​​​​​​​

Framework	Insulation/framework	FF-PIR	u-value W/m2K
Hollow-core slab	Insulation on top of hollow-core slab	FF-EPS M or FF-EPS X 60S/200 mm + bearing layer of wool 20-30 mm	0,14
Hollow-core slab	Insulation on top of hollow-core slab	FF-EPS M or FF-EPS X 60S/320 mm + bearing layer of wood 20-30 mm	0,09
Hollow-core slab	Insulation on top of hollow-core slab	FF-EPS M or FF-EPS X 60S/400 mm + bearing layer of wool 30 mm	0,07
Hollow-core slab	Insulation on top of hollow-core slab	FF-EPS 60S X SILENT 320mm	0,09
Double T-slab	Insulation on top of slab	FF-EPS M or FF-EPS 60S/320 mm + bearing layer of wood 20-30 mm	0,09
Corrugated sheet steel	40 mm stone wool below	FF-EPS M 60S/150 + 150 mm or FF- EPS M 60S/300 mm + bearing layer of wood 20-30 mm	0,09
Glued laminated beam height	FF-PIR 50 mm or Finnfoam 70 mm on the inside	FF-EPS 60S/200 + 200 mm in between	0,07