Pitched Roofs
Issues to Consider Issues to Consider
Design Considerations
Full Fill Between & Under Rafter Insulation
Partial Fill Between & Under Rafter Insulation
Between & Over Rafter Insulation
Over Rafter Insulation
Partial Fill Between & Under Rafter Insulation
Breathable Membrane - Horizontal Installation on Continuous Substrate
Breathable Membrane - Vertical Installation on Discontinuos Substrate
  Pitched Roofs - Issues to Consider
Mineral wool’s layered, fibrous construction can allow an unhindered path for air intrusion at all levels. This means that even the minimum air movement in roof areas required by Building Regulations/Standards can dramatically reduce thermal efficiency.
  • Air movement over mineral fibre as little as 1m/s can lead to increases in heat loss of up to 100%.


  • Air movement through mineral fibre can result in increases heat loss of up to 500%.
Thermographic Image
 
This image shows a ceiling which has sufficient mineral fibre loft insulation in the centre portion but lacks adequate cover at the boundary. The light blue patches indicate the areas affected by cold infiltrating air.
 
Ventilation paths can be vulnerable to blockage due to overfilling
of the eaves with mineral fibre. This can lead directly to creation
of condensation and onset of mould growth.
Overfilling Mineral Fibre
  An example of overfilling of the eaves with mineral fibre blocking the ventilation paths leading to condensation and mould growth.
 
Poor installation of loft insulation could be regarded as
causing:
  • 57% increase in heat loss from the Britain’s roofs; which equates to the unnecessary release of


  • 2,560 million kg of CO2 equivalent emissions per year;


  • 8,937 GWh (million kWh) of wasted heat loss per annum nationally (the equivalent of nearly three power stations!); and


  • £199 m per year extra heating costs.
Missing Mineral Fibre
This image shows the additional layer of mineral fibre missing over a substantial portion of the attic


Kingspan Kooltherm® K7 Pitched Roof Board:
  • can help you to achieve your required U–value with minimal thickness (up to half the thickness of mineral fibre);


  • can help eliminate condensation risk;


  • can eliminate the need for ventilation;


  • are unaffected by air movement; and


  • provide the best thermal performance of all commonly available insulants.
   
Additional Living Space
  An empty attic has as many possibilities as your imagination can create. Warmth, light and air can breathe new life into a dead space.