We are planning a smallish flat roof extension, which has been drawn up with a warm deck flat roof (apparently we are no longer allowed cold deck flat roofs in Scotland?).
The original design had a single ply membrane covering (sarnafil or similar) and I had been thinking of used Zinc or lead instead.
However, someone (not a roofer!) has suggested that I would need to ventilate between the warm deck and zinc/lead. Is this correct?
The flat roof will abut a wall of the house on one side but also join to an existing pitched roof on another side and I was told that might be where it gets difficult, in terms of venting where the lead/zinc is dressed to the pitched slate roof?
Appreciate its difficult to comment with a drawing/photo, but is the priniciple of venting the lad/zinc correct?
The original design had a single ply membrane covering (sarnafil or similar) and I had been thinking of used Zinc or lead instead.
However, someone (not a roofer!) has suggested that I would need to ventilate between the warm deck and zinc/lead. Is this correct?
The flat roof will abut a wall of the house on one side but also join to an existing pitched roof on another side and I was told that might be where it gets difficult, in terms of venting where the lead/zinc is dressed to the pitched slate roof?
Appreciate its difficult to comment with a drawing/photo, but is the priniciple of venting the lad/zinc correct?