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Finishing Basement, Zone 5A

user7610473 | Posted in General Questions on

Hello All!

I am looking to finish a basement in climate zone 5A. The plan is to add an accessory kitchen, full bathroom and half bath. Mechanical ventilation will be provided for the kitchen range and the full bathroom, and there will be a window in the half bathroom. The only heating and cooling will be leakage from the existing HVAC system/ductwork, and electric baseboard heat to supplement in the winter months.

The home is built on a sloped lot where the basement foundation wall on the front and right side of the house is below grade, and the left and rear side of the house is above grade. There are no active water leaks or moisture problems on the foundation walls.

1) It seems as though the two most common wall insulation approaches are either installing 2″ XPS (seas taped) on the walls with no vapor barrier so that moisture can dry to the interior, or installing CCSF. If I were to go the route of using CCSF (fewer chances of air leakage plus the benefit of low vapor permeability), would it be overkill to waterproof all of the foundation walls first (with either cementitious-based Masterseal 583, or with poly-based TREMproof 250GC? I believe I read an article by Joe Lstiburek where he had coated the foundation walls before installing CCSF but that was to make it easier to remove the foam, not to add additional water/vapor protection.
2) For the floor insulation, I am limited on ceiling height so I don’t think that I can get away with 1″ XPS on the floor. What are my options if I were to install laminate flooring (again, height restrictions)? Since the laminate flooring could trap moisture, am I asking for mold?


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