HardieBacker 500 Cement Board is a chemically setting compound for drywall interiors and exteriors that permits same-day joint finishing, and,
usually, next-day decoration. The compound weighs 25% less than conventional setting–type joint
compounds for easy handling and sands easily for fast, smooth finishing. HardieBacker 500 Cement Board is ideal for heavy fills
and is virtually unaffected by extreme humidity. It provides low shrinkage and superior bond,
which makes it excellent for laminating gypsum panels to gypsum panels, and to above-grade
concrete surfaces. In addition, it can be used for filling, smoothing, and finishing interior concrete
ceilings and above-grade concrete; and for finishing joints in exterior gypsum soffit panels.