Styrofoam Insulation Products

Get your Long Island insulation products from 9 Brothers Building Supply!

We are a foam board polystyrene insulation supplier for contractors! We have styrofoam insulation in Riverhead and styrofoam insulation in Brentwood to supply you with all of your construction insulation needs! DOW chemical company brand is the most popular and high quality brand out there; while they own the Styrofoam trademark. This Styrofoam insulation is used in walls, roofing, and flooring to retain heat in the home.

DOW Brand Blue Polystyrene Insulation

Styrofoam Insulation

1″ x 4′ x 8′
2″ x 4′ x 8′
4″ x 2′ x 8′

DOW STYROFOAM™ brand insulation products feature closed cell structure and maintain their R-value over time. The extruded polystyrene insulation products offer the highest moisture resistance of any foam plastic insulation. The result is high compressive strength and unparalleled resistance to water penetration. The polyisocyanurate insulation products do not readily absorb moisture.

R-Value– A measurement of resistance to heat flow. The greater the R-value, the greater the thermal efficiency—and a small increase makes a big difference. Cavity insulation only insulates between the studs, leaving those studs un-insulated. Rigid insulation covers the entire wall, providing a continuous layer of thermal protection and increasing the overall R-value and energy efficiency.


  •  Available in different densities and sizes
  • Styrofoam insulation reduces condensation and moisture
  • Controls heat rapid loss or rapid gain providing a stabilized environment
  • Resists fatigue with strong durability

Styrofoam Insulation Uses

  • Home insulation and commercial insulation
  • Truck cargo insulation
  • Refrigeration insulation
  • Warehouse insulation
  • Attic styrofoam insulation
  • Garage insulation

Delivery across Long Island, NYC, and the 5 boroughs

Construction Site Delivery

Local Pickup

Home Delivery

Contractor & Local Business Deliveries