Moisture Resistant vs Standard Gypsum Board: Performance, Cost and When to Specify Each Choosing between moisture resistant gypsum board and standard gypsum board is a cost-versus-risk decision, not a matter of preference. The measurable difference is in the core: one absorbs water, the other resists it. Side-by-Side Comparison Property Standard Gypsum Board Moisture Resistant Board Core additive None Wax emulsion, silicone or asphalt Water absorption (2 h) Typically 25–40%