Yes, lime mortar is a porous product that lets the house breathe naturally. Victorian houses were built using solid construction walls, which traditionally do not have any cavity or damp proofing. The lime mortar, however, naturally takes away any moisture that gets trapped behind the bricks. Damp is caused when moisture becomes trapped – turning to damp if it has no way of being released, and then potentially causing decay and erosion of the bricks and structure. Lime mortar gets rid of the moisture naturally, which eradicates this serious problem.