The invention relates to a sealant compound comprising, in weight percent relative to the compound total volume: 40-60% of mineral filler whose diameter d50 ranges from 5 to 20 microns, 5-10% of hydrophobic expanded perlite whose diameter d50 ranges from 20 to 100 microns and 4-20% of binder. A method for preparing the inventive compound is also disclosed. Said invention also relates to producing a work provided with joints made of pointing and/or surfacing compound by applying said compound and/or pointing and surfacing by applying the compound which is characterised in that the compound is applied by airless process. According to the inventive method, said sealant compound is embodied such as described in the invention.