I have a third floor above our house with a full set a stairs that we currently use for storage space. The ceiling is well over 10' high in the middle of the room and we would like to convert it to a playroom for our daughter. Currently the room is vented with a turbo fan and two gable vents on each side of the room. It is unfinished.

I would like to insulate between the joists (2x6) with either foam board or possibly the foam vents and fiberglass. My major concern is that we have mild winters and pretty hot summers (live in West Virginia) and I don't want to bake the roof shingles. I would like to maximize the space between the insulation and the back of the roof and am therefore leaning towards the foam board. The problem is the foam board R values are very low (4-10) and I am not sure they will work. On the other hand, I am concerned that the hot air will not flow through the foam vents well enough to remove the heat and that the room will be a sweat box in the summer and possibly bake the shingles. I plan on using the turbo fan to vent the room by building an air duct that connects to the spaces between the rafters.

Also, in the winter the room warms up very easily. I have had my heating and cooling guy out and he said our current unit should be big enough to easily warm and cool the space. However, I am concerned about our ability to make it very cool without heavy insulation??

Help!?

Thanks.

 

Hello
you can install a flat ceiling area 8'6" in the center, how wide would the room be if you keep 4' high side walls? By having the little flat ceiling you can insolat the room cieling and have room over the top for cross ventalation, insulate the side walls of the room, use foam board in the rafter space. add 2" onto the 2x6 and make them 2x8 use 4" foam board, hold it down and make sure you have a clear space from side to side over the top. the roof area should vent as well as it is now and the room will stay at the temp. you would like. for windows you may want to add a couple of dormers to let in air and light. size and locate the doormers so they will add to the outside of house and make them work for you on the inside hope this will help some....Good Luck

 

You might as well forget the foam board idea. The insulation code for your area is R-30 for the attic floors. Foam board will not cut it. You can solve your concerns about the temp by installing a 12" themostat controlled gable fan. If you already have the gable fans, just install thermostats on them. You mentioned turbo fans, but in order for them to work properly, you will need soffit vents.