Below you can find some examples of effective pitched roof solutions made with slabswith blowing wool and with slabs and blowing wool. Below the standard structures you can find solutions for passive houses.


A) With slabs

In cold attics, the large space between the ceiling and external roof structure makes it possible to install an energy-efficient insulation layer. Install the insulation slabs in two or more layers without gaps or cracks between the adjacent components. Generally, you won’t need wind protection on top of the insulation since the movement of air is so small that forced convection does not affect the insulation's performance.

Create ventilation from the eaves with a wind diverter and a ventilation gap of at least 50 mm.

Attic, flexible
  • Roof structure
  • Wind diverter
  • Roof trusses / PAROC eXtra
  • Vapour barrier
  • Grid siding
  • Inner surface

 Insulation solution with U value
 PAROC eXtra
(homogenous layer)
400 mm   275 mm 150 mm 
 PAROC eXtra (frame) 100 mm 100 mm 100 mm
 U value, W/m2K 0.07 0.09 0.14

 

B) With blowing wool

Blowing wool is an effective alternative method for insulating roofs. Installation requires the use of a blowing unit. Only specially trained contractors should carry out the installation. Blowing wool can be installed at heights of up to 40 m.

The wind diverter ensures ventilation in the cold attic area and makes the connection between the external wall and the roof more airtight.

Attic, BLT 5
  • Roof structure
  • Wind diverter
  • Roof trusses / PAROC BLT
  • Vapour barrier
  • Grid siding
  • Inner surface
 
 
 Insulation solution with U value
 PAROC BLT 6 
(homogenous layer)
520 mm   320 mm 170 mm 
 PAROC BLT 6 (frame) 100 mm 100 mm 100 mm
 U value, W/m2K 0.06 0.09 0.14

C) With slabs and blowing wool

Use slabs and blowing wool to create double layer of insulation. The sturdy PAROC eXtra stone wool slabs provide a solid base for blowing wool to adhere to, making it especially suitable for pitched roof applications. PAROC eXtra slabs provide insulation for the building stage, and when work on the roof is finished, Paroc-authorised contractors can install blowing wool on the top of the slabs.

 

Pitched roof with slabs and blowing wool
  • Roof structure
  • Wind diverter
  • Roof trusses / PAROC eXtra + PAROC BLT
  • Vapour barrier
  • Grid siding
  • Inner surface
 
 
 Insulation solution with U value
 PAROC BLT 6 
(homogenous layer)
510 mm   310 mm 160 mm 
 PAROC eXtra (frame) 100 mm 100 mm 100 mm
 U value, W/m2K 0.06 0.09 0.14


Passive houses

Passive house roofs are similar to standard house roofs – the insulation layer is just thicker. Select roof trusses that allow for the needed insulation thickness. At the same time, a bit higher support height for the roof trusses lifts up the appearance of façade. 

Attic, flexible, passive house
  • Roof structure
  • Wind diverters
  • PAROC eXtra (d1)
  • Roof trusses / PAROC eXtra (d2)
  • Air/vapour barrier (all joints to be taped)
  • Studding / PAROC eXtra (d3)
  • Inner surface


  Block of flats  
Recommended U value   W/m2K  0.06 - 0.09
 d1  mm  300 - 475
 d2  mm  100
 d3  mm  50
 Total insulation thickness  mm   450 - 625

The solution below uses both PAROC eXtra and blowing wool:


Attic, flexible BLT, passive house 2 
  • Roof structure
  • Wind diverters
  • Thermal insulation: PAROC BLT (d1)
  • Roof trusses / PAROC eXtra (d2)
  • Air/vapour barrier (all joints to be taped)
  • Studding / PAROC eXtra (d3)
  • Inner surface
 
  Block of flats  
Recommended U value   W/m2K  0.06 - 0.09
 d1  mm  375 - 600
 d2  mm  100
 d3  mm  50
 Total insulation thickness  mm   525 - 750


The third option is to use mainly blowing wool. It is usually the fastest way to insulate the attic.

Attic, flexible + BLT, passive house
  • Roof structure
  • Wind diverters
  • Roof trusses / PAROC BLT (d1)
  • Vapour barrier (all joints to be taped)
  • Studding / PAROC eXtra (d2)
  • Inner surface

  Block of flats  
Recommended U value   W/m2K  0.06 - 0.09
 d1  mm  500 - 750
 d2  mm  50
 Total insulation thickness  mm   550 - 800

Notes:
According to the definition of a passive house provided by the Passive House Institute, the annual heating, cooling and primary energy demand should not exceed certain values. Although good thermal insulation plays a major role in achieving the Passive House standard, it alone cannot ensure compliance. The requirements for other building components and devices can be determined by various calculations tools, such as the Passive House Planning Package (PHPP), available at www.passiv.de.