Kingspan insulation

[smiffymate]

I am putting 70mm insulation between 100 mm fafters and leaving a 30 mm airgap to the roof felt.How can i fix the kinspan other than making it a tight fit and squeezing it in

[bertie]

Link deleted as no external links allowed. Diydoctor web staff rely on advertising for their living so we cannot give it away.

I recently printed off 15 pages on Koolthern K7 Pitched Roof Board, and on page 12 under Sitework it lists 3 methods for installation between rafters based on the depth of the rafters compared with the depth of the insulation. Fixing for insulation less than the depth of the rafters should be done by nailing battens to the inside of the rafters so that the insulation is flush with the bottom of the rafters and should fit tightly with all gaps sealed with expanding urethane sealant.

Have a look for yourself, as I am no expert. Indeed, I read this to be contradictory.

Good luck.