I have a couple questions on how to provide insulation for the ceiling of an indoor swimming pool under construction in Oregon. Here are photos and plans (not to scale): http://s1007.photobucket.com/user/fe...ry/Pool%20Roof. Part of the pool ceiling is exterior roof with single ply torch down roofing. This area will also have a walking deck consisting of wood 2x4 removable sections (pallets) in case roof leak needs to be repaired. There is no possible way to vent cavity between insulation of ceiling and plywood sheeting, because of walking deck structure on the top of the roof. Also joists are running parallel with exterior walls and in addition there is already installed stucco on the exterior walls. Roof will be exposed to outside temperatures that range from below freezing level in the winter and above 100F in the summer, while swimming pool room temperature will be 85F.

The other part of the pool ceiling is upstairs master bedroom with temperature fluctuating from 55F in the winter and 95F in the summer when home is not occupied or owners are out of town for longer period of time. Otherwise temperature in master bedroom should be around 70F.

Structure of ceiling (roof) of swimming pool consists of gluelamb beams which are carrying TJI trusses (11-7/8 high) and are spaced 12 on center. Pool room is approximately 1000SF and height from floor to ceiling is approximately 15FT. Side walls are mostly consisting from patio doors 8-0 x 8-0 and transom windows above 8-0 x 3-0. The west wall divides swimming pool from finish basement (family room) and first floor above basement (the entry to house and living room). The question is how to provide insulation of cavity between TJI trusses, gluelamb beams, exterior & interior walls.

Mechanical room is equipped with Dectron dehumidification system to keep indoor humidity around 50% to 60%. This unit will also provide heating and cooling. Fresh air intake will connect to Dectron dehumidifier to improve the quality of the air. Near Dectron return register will be installed in exhaust fan. This exhaust fan helps to increase proper circulation of air in the pool house and it helps to keep negative pressure when fresh air intake is open. Swimming pool will have automatic pool cover which helps to save some energy cost during non-occupied time and decrease humidity. The State of Oregon energy code requires for flat roof insulation R-38. The question are detail and what kind of insulation, vapor barrier, and sealant to be used.

Completely unrelated subject is duct for heating, cooling and dehumidification of swimming pool. Due to specific requirements, the location of duct is limited between gluelamb beams and transom windows to height of maximum 10. Duct shape should be flat oval to improve air flow. Beginning size should be 10 x 30 which periodically changes after each register to final size 9 x 13 at the end. At the end of flat oval shape duct changes its shape to three round ducts. Those will be placed in the ceiling between TJI trusses, each in different bay to bypass gluelamb beams in order to get to the desired location. Because of swimming pool environment it is a potential problem with galvanized duct unless sufficient treatment and protection is provided to extend life of duct. Aluminum and stainless steel are very expensive. Would you please advise what duct to use and possibly a source where to find a reasonable fabricator of duct?

Thank you very much for your help, your assistance is greatly appreciated!