How does foamboard insulation work and how is it different than fiberglass insulation? This is a common question asked at Universal Foam Products. It’s all down to millions of air pockets formed when the material is molded. These pockets reduce the flow of heat; heat is kept in during the winter and kept out during the summer. This structure also helps to prevent moisture absorption, unlike fibreglass, meaning EPS foam board is not affected by dampness from the ground or water damage. Our knowledgeable and friendly customer service team are always available to answer your questions on 410-498-0000.