Basement insulation questions
Preparing to finish a currently unfinished basement in Chicago (Zone 5). Ideally we would have used pre-extruded foam on the walls, however when the home was originally build the main plumbing drain lines were installed tight to the foundation walls and reworking these is too cost prohibitive.
With this said our installer is suggesting 3″ of closed-cell spray foam for an R21. Code is R15, is their suggestion worth the potential extra cost?
The other question is in several areas we our walls are several feet from the foundation due to water services, sump/ejector pits, or other plumbing obstructions. These areas can’t be sprayed, can’t spray in main copper supply and or village meter, nor can rigid foam insulation be added. What is the suggestion for insulation in these instances?
GBA Detail Library
A collection of one thousand construction details organized by climate and house part