Fiber cement building materials with low density additives

摘要

This invention relates to a formulation with the addition of hollow ceramic microspheres into cementitious cellulose fiber reinforced building materials. This formulation is advantageously lightweight or low density compared as compared to current fiber cement products without the increased moisture expansion and freeze-thaw degradation usually associated with the addition of lightweight inorganic materials to fiber cement mixes. The low density additive also give the material improved thermal dimensional stability.