Client: Zenon builders, 

Duration: 1 day

U-value target: 0.18 W/m2K

Air tightness target: no target 

Cost: £22/m2

Installation area: 85m2

Location: London, W1G

Existing build-up specifications

  1. Tiles
  2. Battens
  3. Breather membrane
  4. 150mm rafters
  • 50mm ventilated air gap
  • 100mm rigid insulation board
  1. 62.5mm insulated plasterboard
  2. Skim and finish

Proposed build-up specifications

  1. Tiles
  2. Battens
  3. Breather membrane
  4. 150mm rafters
  • no air gap (Icynene is breatheable)
  • 150mm Icynene H2Foam Lite
  1. 62.5mm insulated plasterboard
  2. Skim and finish

Problem 

Time constraints on this project coupled with the clients desire for a more energy efficient home were the key reasons for Zenon builders to trail Icynene H2foam.

Solution

London insulation installed the 85m2 timber roof structure in one day, trimming back the foam to allow for the fixing of insulated plasterboard which Zenon builders were able to continue with that afternoon.

Result

The client now has a roof structure with a u value of 0.18 W/m2K that complies to building regulations but also an air barrier that will make the roof up 50% more energy efficient.