Client: GB Building Solutions,

Duration: 4 Weeks,

U-value target: 0.11 W/m2K

Air tightness target: 5 ach

Cost: £41 m2

Installation area: 1700m2

Location: Marlow, Buckinghamshire

Existing build-up specifications

  1. Tiles
  2. Battens
  3. Breather membrane
  4. 250mm rafters
  • 100mm ventilated air gap
  • 150mm rigid insulation board
  1. 60mm insulated plasterboard
  2. Skim and finish

Proposed build-up specifications

  1. Tiles
  2. Battens
  3. Breather membrane
  4. 250mm rafters
  • no air gap (Icynene is breatheable)
  • 250mm Icynene H2Foam Lite between rafters on sloping ceilings
  • 350mm Icynene H2Foam Lite between and over rafters in ceiling and eves
  1. 70mm insulated plasterboard on sloping ceilings
  2. Skim and finish

Problem

Guaranteeing a continuous insulation layer and air barrier between the insulated concrete form work walls and warm deck roof presented a significant challenge to the main contractor. Trying to achieve a u value of 0.11 W/m2K and a target of 5 ach would be a costly and time consuming process using ridged insulation boards and air tightness membranes.

Solution

Using Icynene H2Foam Lite spray foam insulation has guaranteed achieving air tightness and a full, unbroken layer of insulation in this section of the building.

Result

On a project of 1700m2 London Insulation were able to install over 100m2 of Icynene H2Foam Lite spray foam insulation on average a day. This has significantly sped up this part of the build process resulting in GB Building solutions being able to reduce there preliminary costs for the project. Adopting this new method of working will give GB Building Solutions a competitive advantage when tendering for future projects.