London sits on the Thames Valley Basin, a low-lying region with layers of clay and that is a primary cause of damp and mould, which can lead to serious repairs. In this short blog, we offer a few of the common causes of damp and mould in London properties.
- Leaking roof – Even a small leak will eventually lead to water penetrating the interior roof structure; rafters and joists can be easily damaged and mould can thrive in such an environment. We recommend inspecting all timbers in the loft; take a flashlight and inspect every corner, looking for tell-tale signs of moisture damage. Our pre-purchase survey includes a detailed roof inspection both inside and out and if there is damp in your home, we will find it.
- Defective damp proof course – All buildings have a damp proof course (DPC) inserted between brick courses at ground level and if that is damaged, moisture can rise up the walls and that causes damage to the substrate. In some cases, it is better to inject a chemical DPC than try to repair the original DPC membrane; this provides an effective moisture barrier that protects the building from rising damp.
- Crumbling masonry/mortar/render – Buildings are fully exposed to the harsh British climate and years of driving rain can degrade exterior walls; you should inspect the exterior of your home, specifically looking for crumbling materials and moss growth. Take a screwdriver and test the integrity of the building materials to see if damp is present, it is often the case that mortar becomes soft and powdery and repointing becomes necessary.
- Bad habits – If you like to dry clothes in the house, this will add a lot of moisture to the air and condensation can form on cold surfaces. Cooking causes steam and if you don’t have an extractor fan in the kitchen, condensation is likely to be the result. If you don’t open the windows from time to time and the air is damp and still, mould can thrive and that is a health hazard. Running a hot bath is fine, but you should open the bathroom windows and turn on the extractor fan to dissipate the condensation. Don’t open the door until the moisture has gone, otherwise, moisture enters the house.
- Poor ventilation – Many old London properties have this problem and mould quickly establishes itself, which is a health hazard with prolonged exposure. Opening windows and heating the house are two ways that you can reduce the moisture in a house; using a dehumidifier is another effective way to dry out a room. You can measure the relative humidity using a hygrometer.
If you would like a definitive damp inspection in your London home, call London Damp Surveys on 0207 305 5997 or fill in the online form on this website. You will receive a detailed report within 24 hours of the survey completion.
