Apply a salt neutraliser and replaster Then, you will need to apply a salt neutraliser before replastering. For further protection in preventing condensation and damp forming in your chimney, you can also apply a damp proof membrane. These work by stopping moisture and salts from permeating into your wall.Click to see full answer. Also asked, how do I fix condensation in my chimney?The simplest and most cost effective solution is to place a stainless steel liner inside your existing chimney. This liner reduces the usable air of your chimney, helping the more efficient furnace exhaust to rise all the way to the top and exit your chimney.Beside above, does rain come down the chimney? Unless a chimney has a cowling, rain often comes down its relatively small aperture. But all chimneys have a bend built into them to prevent any downdraught. Any normal rain will be absorbed by the insides of the chimney and prevented from going all the way down by this ledge. Likewise, people ask, why is my chimney sweating? Normal Chimney Condensation When it’s cold outside and the warm, humid air inside the home contacts the cold walls of the chimney, the warm air will condense on the cold surface and result in dripping. The sweating in this case is normal and will cease once a fire is built and the chimney heats up.Will insurance cover chimney repair?Common chimney work like masonry repair, damper repair or chimney cover replacement in general are not covered by homeowners’ insurance policies. When the repairs are part of normal wear and tear insurance companies again see this as a homeowner’s responsibility in operating the fireplace and chimney safely.