A fire-resistant thermal insulation product may be used in new home
construction and/or remodeling projects of existing buildings. Individual
beads or small clusters of polystyrene (PS) beads are obtained by
processing gleaned waste polystyrene through a plastics granulator or
other cutting or grinding device. The PS beads and/or small clusters are
coated with liquid intumescent fire retardant (FR) and dried. A binding
solution is added, and the resultant FR-coated PS plus binder is
compacted into self-supporting blocks. Each block is then dried, and
subsequently placed in a polyethylene bag and sealed. The blocks are
appropriately sized to fill the cavity spaces between wood and metal
studs in both exterior and interior walls of buildings, between the
ceiling joists in attics, and floor joists in crawl spaces. The width,
thickness, and length of the solid rectangular shapes are variable, for
example, varied for 16-inch-on-center and 24-inch-on-center framing
spacing, and for various cavity dimensions and desired R-values. These
insulation products meet the required safety test criteria, such as ASTM
E84 and UL 94, necessary to meet building code requirements and ICC-ES
certification.