Still getting black mould in Victorian house

Hi Karen, Without actually looking at the issues it is not possible to give you an exact cause, but will try to let you understand your building and its material. Your type of building will be of solid wall construction, no cavity. It will have been built using lime mortar, this allows your walls to breathe, stopping water ingress. New materials and old materials do not work very well together There is no cement in lime mortar, plaster or render. No additives, only hydraulic or non hydraulic lime, NOT hydrated lime which can be purchased at any builders merchants but requires cement for it to set. If it has been re-pointed using a cement based mortar this will trap water behind the mortar in the structure of the building, as there is no cavity, the water can only go one way inside creating cold and damp. In this world where everyone wants instant solutions, most modern damp proof solutions are designed to cover up the issue rather than solve the problem of where the water is getting in. It is often mistaken for rising damp, this will result in a injected damp proof course being suggested, this solution does not work in this type of property and usually results in your dampness coming back worse than before. Your best option is to find a company that deals with older properties, the building materials that they are constructed with and how they work. All these materials are still available although dearer, finding someone who can use them and understand them is a tad harder should you wish any further info feel free to ask. Good luck Alex

Hi Condensation is caused by increased water vapour within the humidity of the property, this will then cool and cause water droplets on cold surfaces - these are called dew points. Although ventilation helps, this is not always the cure. Firstly check what you may be doing that's increasing the humidity ie - drying clothes on radiators etc, making lots of steam when ironing or cooking without extraction, bathing and showering without adequate extraction, these are the first steps to improve the amount of vapour. Secondly check where the condensation is forming most and in some way increase the surface temperature - ie insulation materials Then look at ways to remove the remaining vapour - passifier vents are a fantastic remedy if installed into the appropriate location. Hope that helps - Nigel