9 Brothers Building Supply is your source for Brentwood Styrofoam insulation. Styrofoam Insulation is a must for any project with thermal sensitivity. We are a foam board polystyrene insulation supplier for contractors! We have Styrofoam insulation in Brentwood and Styrofoam insulation in Riverhead to supply you with all of your construction insulation needs! DOW chemical company brand is the most popular and high quality brand out there; they own the Styrofoam trademark after all. Stop in today and find the Styrofoam you need for your project!