A process for producing a polyurethane or polyisocyanurate construction board, the process comprising of providing an A-side reactant stream that includes an isocyanate-containing compound; providing a B-side reactant stream that includes a polyol, where the B-side reactant steam includes at least 0.5 parts by weight water per 100 parts by weight polyol within the B-side stream; and mixing the A-side reactant stream with the B-side reactant stream to produce a reaction mixture.
