Should you use lime on your property?
People get told so much different (often conflicting) information regarding the use of lime. The truth in the matter is this; if the building in question is constructed with solid walls (without a cavity) or damp proof course then it is a building that needs to breathe and should be treated accordingly.
Lime products allow the walls to 'breathe'. Now they don't breathe in the same way a human breathes, but its a good analogy to understand the process that is happening. As the walls warm up and cool down throughout the year, day and night, small amounts of air are taken in and expelled. Of course with this air comes moisture, especially if the climate is very humid. If the wall is allowed to breathe, this will not cause any problems. The problems begin when incompatible materials are used on the walls; such as cement renders, gypsum plaster, plastic paints, kingspan insulation etc. These products have been designed to work with other non breathable building materials. It's all good stuff when it's used in the right situation. A solid wall is not the right situation - they seal the wall, so when moisture and air try to escape they can't. Eventually this can force the coverings off the walls causing cracks and flaking plaster etc. The knock on effect is that through these cracks there will be more water ingress and the process will continue getting gradually worse. Combine this with poor guttering and drainage around the buildings and you can have some serious damp issues. Damp cold walls are also a perfect start for mold growth and can cause an very unhealthy living environment inside the home. Unfortunately this is the case with a huge proportion of the country's heritage buildings today.
Inexperienced tradesmen or surveyors who haven't been told the correct information will talk about rising damp and sealing up walls and will suggest solutions such as damp proof injection and waterproofing products. DO NOT use these products on your building. They don't work. They may create a temporary fix, but will eventually make your problems worse.
Use the correct breathable lime mortars, paints, insulation and you will keep your building happy and consequently create a healthy living environment inside the home.