How do I adequately insulate my attic roof to make the space a bit more habitable in the winter? The floors to the living area below are already insulated and we have a gable mounted fan which is great in the summer. I am thinking of adding insulation to the roof with baffles underneath for air circulation through the soffit vents. Am I anywhere near an idea that may work?
Such an interesting question when you sit down to answer it. First off, if there are any vents to the exterior, its not likely that you will want any additional heat to enter the space, as it will flow out of the vents to the outside and cost far more money than heat that is lost by thermal transfer, through the doors, windows and insulated walls and ceilings. So, any increase in the source of heat would mean closing the system to outside air vents like the fan and the soffit vents. If you want to heat the space, you'll need to insulate the roof by adding fiberglass batting to the space between the rafters and then drywall or panel depending on local building code and your preferences. Then you'll need an avenue for heat to reach the attic which can be as simple as cutting a couple of floor grates through to the heated space below, but you'll want cold air return ducting to send the cold air that is displaced by the heated air back down to the furnace. Then you'll need to seal the gable fan and insulate, perhaps with a box you can remove in the spring and replace in the fall. Now that the attic is integrated in the HVAC system, you no longer need the soffit vents. If you don't have a forced air system, there is less concern about the cold air return, as your heat source would be in the room or you can just use floor grates on opposite ends of the room for both the warm air and cold air exchange. Place one near the heat source below and one well away from it.
you live in the conditioned air box! you can't change your wall insulation, just add more to the ceiling. don't block roof vents as they are as important in winter as summer. if you have an unfinished basement, you may want to consider sealing off the joist with plastic or tyvek depending on your conditions ( north or south ). most bang for the buck is ceiling insulation.
What you could do is line inbetween the roof trusses with fibre wool and then fix heavy cardboard sheets over them to keep them in place. Alternatively you could engage the services of a specialist company who will come and strip off your tiles/slates whatever and spray an insulating foam on the inside thus sealing everything in place.
