Cellar Tanking – The Condensation Problem and How to Avoid it Part 2 – What Causes Condensation?
The average basement tanking system will cost many thousands associated with £ ‘s. The primary purpose is to keep out surface water, but how often perform we think about the internal naturally taking place atmospheric humidity? We ignore this particular at our peril; cellar tanking and other forms of basement protecting can interact with humidity and result in condensation problems… My last post on cellar tanking and moisture build-up or condensation looked at what condensation is. Condensation occurs wherever the humidity and temperature combine to create ‘dew point’. So we need to take a look at those specific factors in a tanked cellar or waterproofed basement that will cause temperature and humidity to come together in this way.
Waterproof coatings or even membranes are not usually very thermally efficient so they can get cold. And they are usually applied to the internal surface area of the outside walls during a basement conversion or basement waterproofing task this makes them even colder. If we put insulation in front of the water-proof membrane this insulation makes the cooler still (insulation keeps heat within the room and therefore away from the particular membrane).
If the cellar or cellar is heated with an irregular basis this can give increase to periods where the temperature is actually low to avoid condensation.
Moisture vapour in the air will move in almost all directions, so not only is humidity vapour coming into a basement or even cellar from the ground outside, it is also moving from the internal desert of the cellar or basement to the outside. An effective waterproof hurdle (tanking system), designed to work against the ingress of ground drinking water will also prevent the escape of inner moisture vapour. Rooms below floor are generally more difficult to ventilate because of to lack of windows and doorways. General living generates moisture fumes, even breathing and perspiring, furthermore cooking, drying clothes, boiling kettles using a shower or bathroom with out adequate air extraction all lead to internal moisture vapour. This in itself is not necessarily a problem. It only becomes a problem is any area of the cellar or basement as a temp which is equal to or beneath the dew point temperature and the most likely place for this (cold) dew point temperature is the water-proof barrier itself. In my own expert experience I have seen many situations of otherwise good cellar transformation and basement waterproofing projects destroyed due to condensation.
In our next article I will be looking at destruction that it can do, not only to the building fabric, but also to the fitness of the occupants.
Meanwhile to learn more about problems with cellar tanking and just how to avoid them click cellar tanking.