Looking for some incite on insulation techniques for old basement walls for finishing basement.   I under stand the best option for new construction is spray foam and batt.  Next foam board with no air gap then batts.    Climate zone 5 and Denver which is a dry climate.    My question is what if water/moisture cannot be totally mitigated from the exterior?    My foundation is 100 yr old poured concrete that is SOFT concrete with an interior parge coat.  The foundation was dug and waterproofed with dimple board from the exterior however due to the concrete not being originally formed and some construction uniqueness, the exterior waterproofing is not 100%.       The basement had an 80s renovation where one side of the foundation was framed with 1.5″ furring, white styrofoam board, plastic sheet, then drywall.  When demo’d this wall had the concrete parging loose and crumbling and separated form the foundation wall (I speculate due to trapped moisture); the wall had to be completely reparged.     The other wall was left exposed with no insulation and the parge coat was generally totally in tact.   This leads me to believe that the wall needs to breath and have airflow?     So for structural performance of the wall, is an air gap between the concrete permissible if using foam board?   I fear spray foam will trap water moisture and spall off the parge coat again.    Any other options?  thanks!