My conservatory is fitted with 16mm polycarbonate triple wall sheeting and in order to reduce noise and increase thermal performance I have been looking at 35mm polycarbonate. Unfortunately I do not think the roof bar rebate can take 35mm sheeting. I wonder whether it would be worthwhile fitting secondary glazing on the underside of the roof bars. The gap would be about 30mm and I thought of fitting twin sheet polycarbonate.
Any thoughts from readers and/or professionals would be very welcome.