Apart from good insulation, it is also important to focus on airtight construction, as this further minimises heat loss and prevents moisture problems. Airtight construction keeps heat from escaping the dwelling. Wind, heating and mechanical ventilation create pressure differences between the indoor and outdoor environment, enabling air to escape through cracks and crevices which, in turn, causes heat loss. It’s also important to note that the escaping air also contains moisture that may condense in the construction of a dwelling. In turn, this condensation may result in building damage.
So it is fair to conclude that the more leaks a dwelling has, the less airtight it will be. Good airtightness limits the leaks through which draughts can enter the dwelling to a minimum, and this will lead to greater comfort. After all, in cold weather we also keep our winter jackets zipped tight in order to keep warm ...
What is the importance of airtightness?
When a construction isn’t airtight, a lot of heat seeps out through cracks and crevices. This not only has a negative effect on the level of comfort (draughts) but it also impacts your energy bill. Moreover, poor airtightness can cause moisture problems.
Moisture problems due to poor airtightness
When a construction is not completely airtight, hot and moist air from inside the dwelling can make its way outside through the construction. The warm and moist air cools off and condensation appears on the colder parts of the construction. This moisture makes the insulation less efficient and may cause damp patches and mould.
Read all about condensation
Impact on energy loss
The more energy-efficient a dwelling, the bigger the impact of poor airtightness on the remaining energy consumption.
Airtightness is not the same as windtightness
Windtightness refers to air permeability from the outside in, and it is crucial for the actual energy performance of the building. Good windtightness prevents air circulation behind the insulation layer, which could partially cancel out the effect of the insulation. But as far as comfort goes, it is also important to stop the wind on the outer surface so there are no draughts inside the dwelling.
UNITAPE provides a windtight finish for the PIR insulation boards. This tape is applied to the seams, which must be dry and clean. Take care to press the tape firmly across the entire length.
Advantages of UNITAPE:
- Very flexible, so ideal for corners and hard-to-reach places
- Excellent adhesive strength, also over the long term
- Resistant to ageing
Airtightness and ventilation go hand in hand
A healthy indoor climate is extremely important. That is why an insulated dwelling must also be ventilated. Everyday activities such as cooking meals, taking a shower, sleeping and cleaning generate polluted, moist air. This unhealthy moist air must be changed on a regular basis, and that is where the ventilation system comes in. (Unwanted) air leaks frequently occurred in old dwellings, but this is no longer the case with modern, airtight constructions. Insulation, airtightness and ventilation go hand in hand!