No. Any Gypsum plasterboards (including the Siniat fire-rated pink boards) are materials of limited combustibility and should not be used for fireplaces. We would suggest using Promafour® fireplace insulation system used to build a false chimney breast for a cassette/inset type fire place, or line existing chimney breast against concrete or timber frame. For more information, please refer to our Promafour® How-To Installation guide.