JM Spider Custom Insulation System

JM Spider Custom Insulation System

Credit: Johns Manville Corporation

What makes this product green?

  • Reduces heating and cooling loads
  • Low-emitting


Johns Manville’s Spider Custom Insulation is a formaldehydeChemical found in many building products; most binders used for manufactured wood products are formaldehyde compounds. Reclassified by the United Nations International Agency for Research on Cancer (IARC) in 2004 as a “known human carcinogen."-free spray-applied fiberglass suitable for walls or ceilings in commercial or residential applications. Spider uses a polyester-based binderGlue used in manufactured wood products, such as medium-density fiberboard (MDF), particleboard, and engineered lumber. Some binders are made with formaldehyde. See urea-formaldehyde binder and methyl diisocyanate (MDI) binder. that when applied with 10% or less moisture content requires no drying time before covering. According to the company, this fiberglass fills gaps and will not settle. Spider can be applied in either 1.0 or 1.8 pounds per cubic foot densities with R-values of approximately 3.7 or 4.2 per inch, respectively, and has a Sound Transmission Class (STC) rating of 43 in a standard 2x4 wood-framed wall. SCS-certified to contain 25% recycled content (20% post-consumer) and passes California’s 01350 for low-emissions. Spider can also be formulated for use attic and drill-and-fill insulations in walls. Johns Manville uses a proprietary mold inhibitor in these products.

Additional Info


  • California Section 01350
  • SCS Recycled and Material Content

Manufacturer Information

Johns Manville Corporation
717 17th St.
P. O. Box 5108
Denver, CO 80217
Phone: 303-978-2000
Fax: 303-978-3661
Toll-free: 800-654-3103

Listed in: Blown Insulation, Sprayed Insulation