Insulation in Basement

Hey folks,
Im in the process of upgrading some items in my house. The remainder of the windows will be replaced this year as well as the boiler & HW heater within the next couple of weeks. My heat loss calcs leave a little to be desired for increasing overall heat retention. I figure one of the places to start is in the basement.

My house is a ranch, approx 90 feet end to end. The horizontal rafters are 2x12's centered on 24" spacing that all sit upon a cinder block foundation with a thin insulation layer sandwiched between the wood and cinder block along the whole perimeter. But there is no insulation above that! So effectively, what I envision is a transfer of heat to/from the outide (the exterior is stucco layered).

Would this be the 1st place to start? And will fiberglass insulation be sufficient or does it need to foam sprayed instead?

 

A ranch style house is mostly roof, and most of the heat loss is thru the ceiling. Upgrade the attic insulation to at least R-38. Make sure the attic space is properly ventilated, with soffit AND ridge vents. There is not a lot you can with the walls without tearing everything out and rebuilding with 2x? walls. That would save heating/cooling costs, but you will never see a payback in your lifetime.

 

I think Bill was thinking your basement if finished. It sounds to me like it is not.
Just for info, the horizontal "rafters" that make up the first level floor are joists, not rafters. The joist that runs the perimeter along the top of the blocks, perpendicular to the joists is called the rim joist. It sounds to me like you want to insulate the space along the rim joist. Does that sounds right?

 

Yes, that's right the joists, and the rim joists (perimeter). Mixed that one up.
Basement isn't finished.

Above the ceiling and in the walls is R19 b/c of 2x6 frame construction and am not changing that out! Just sealing up the windows as best possible when the new ones are installed.

 

Nowadays spray foam is done on the rims because it gets in all the nooks and crannys. Its spendy though. You would likely be good just cutting some R19 fiberglass bats and filling the space. Less messy too. As Bill said, the roof is where you lose most of your heat.

 

So fill in with R19 batts - got it. Thank you~~