Have moved into 1960 dormer bungalow and want to increase lagging in roof. Present roof has 3 foot wide, half inch thick polystyrene laid over rafters, with 6" overlaps. This is covered by roofing felt and then cement tiles. Can I just fill in-between the rafters with any type of lagging? Do I need to leave an air-gap for ventilation?
At some point a new hip roof was added. In areas I can see the Tyvec membrane, and where the polystyrene has been damaged the roofing felt. This must create cold spots. What is the best way to reinstate the original warm design?
At some point a new hip roof was added. In areas I can see the Tyvec membrane, and where the polystyrene has been damaged the roofing felt. This must create cold spots. What is the best way to reinstate the original warm design?
