What is the best insulation for concrete block foundation wall and basement stud wall system?

Don Fraser

My daughter has a 1954 storey and a half house with a concrete block wall foundation. I have a 1975 home with a block wall foundation. Both of us want to insuate the basement walls. She wants to spray foam the rin joists and  apply 2" of foam on the walls with the stud wall being installed 1" from the block wall. However I  am concerned that concrete block needs to breath, based on what I have read on this site, and that the temperature of the block will now be colder with the insulation on it and will cause damage to the block and morter. How should these walls be insulated. Is a gap required under the sill plate to let moisture out and prevent rot of sill plate ( proposed sill plate is pressure treated wood.)

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