For finished basements, standard or high-performance batts can be used depending on the R-value required. It is important to verify if there are any moisture penetrations in the basement walls prior to insulation installation. As in sidewall construction, vapor retarders should be installed either as facing on the insulation or as polyethylene sheeting.
For unfinished basements that contain furnaces, water heaters, ducts, etc., manufacturers offer special basement wall insulation that is available in 4- or 6-ft widths in 50-ft rolls. It typically comes with a white or aluminum, flame-resistant polypropylene protective facing and is intended for use in applications where the insulation will be left exposed. It can be applied either full or half wall height (Fig. 8.10).