Advanced Spray Foam Ltd.
FOAM-LOK can be installed between rafters to the required thickness in order to provide a particular level of insulation or U-Value. The open cell spray foam can be cut flush with the adjacent timbers to allow for plasterboard fixing or can be sprayed proud of the roof rafter to the desired thickness. Please contact Advanced to arrange for your particular U-value calculations specific to your build. As with all insulation types FOAM-LOK can be applied to breathable roofing felts when a counterbatten is present above the felt and below the tile / slate batten in accordance with Irish and UK Building Regulations.
The above detail allows for the necessary ventilation layer above the vapour permeable roofing felt. In circumstances where the roof is not “counter-battened” it’s necessary to install rafter slide to the underside of the felt. This effectively provides a separation layer between the foam and felt to allow for ventilation as required by regulation. A rafter slide must always be installed when a non-breathable roofing felt is present.