Isover presents Luro and Luroche, two mineral wool solutions for sarking

The sarking technique makes it possible to keep the surface under the roof and therefore to be able to arrange the attic, unlike conventional attic insulation, which encroaches on the square meters available under the roof. This technique creates continuous insulation from rigid insulation placed between the frame and the roof. The frame supports the roofing elements by means of counter-rafters.

To implement this solution, Isover offers 2 choices of insulation: Luro in glass mineral wool and Luroche in rock mineral wool. The Luro offers a certain ease of cutting and use thanks to its lightness. In both cases, the wooden frame remains visible, for a certain aestheticism, and the living area is preserved.

Excellent thermo-acoustic performance

With mineral wools, the Sarking solution provides excellent acoustic performance (RA.tr = 39 dB.). It also makes it possible to meet the requirements of RT 2012 and BBC renovations, by considerably reducing thermal bridges by means of cross-layer insulation. The insulation products in the Luro and Luroche range come in the form of rigid panels, applicable in single or double layers. The thermo-acoustic performances are certified by CSTB (ACERMI).

Implementation in 5 steps

Laying the deck and the Stopvap membrane

A continuous decking, made of wood-based or batten-based panels, is fixed to the rafters.

The Stopvap membrane is unrolled horizontally with an overlap of 10 cm on the decking. The junction between membrane strips is ensured with Vario Multitape adhesive.

Laying the insulation in 1 or 2 crossed layers

Luro or Luroche insulation panels are installed edge to edge and with staggered joints.

The second layer is also laid with crossed joints and offset from the first layer.

Installation of the HPV screen under the roof Intégra screen

The Integral Screen is rolled out horizontally, starting from the bottom of the ramp. The connection between strips is ensured by leaving an overlap of 10 cm

• in the case of a slope> 30% and 20 cm
• in the case of a slope? 30%.

Installation of counter rafters

Counter-rafters with a minimum width of 60 mm are positioned directly above the existing rafters and then fixed using special double-threaded Sarking screws.

The screws are alternately oriented at an angle of + 30 ° and -30 ° with respect to the roof plane to improve the resistance to tearing of the latter. In the running part, provide 1,7 to 2 screws per m² at a distance of 0,55 to 0,90 m depending on the case.

Laying battens

A bedding perpendicular to the counter-rafters is ensured using nails. It constitutes the support for laying the roofing elements.

In the event of a mountain climate, a second decking will be fixed on the counter-rafters. This decking will support additional waterproofing.