Air tightness is a significant contributor to energy efficiency and emission rates of any building, ensuring that specific performance requirements are met. Air leaks in a building can lead to energy consumption, especially when replacement air is conditioned. Air leaking also feeds condensation which causes performance problems. The leaks also have the potential to bring polluted outdoor air into the building.
Air tightness testing is an assessment process that focuses on air permeability, leakage or tightness in a building. The higher the tightness levels the greater the energy efficiency of your building. Building regulations give guidelines on new dwellings and non-residential buildings like offices. The testing is done to ensure that the regulations are met and that the performance of the building as far as retaining conditioned air is at par. This is a process that helps in identifying areas that need improving to minimize loss of conditioned air and at the same time maximize energy used in cooling and heating the building and reducing overall emission rates of the building.
If a test fails, appropriate recommendations are given to make improvements in the air tightness of the building. But fortunately there is always something you can do to make your building airtight so you pass the air tightness testing.
1. Have an air tightness strategy before you even start building. You can use the guidance of a professional so you have your air tightness barriers defined early in the project. The professional should be able to coordinate between all necessary trades and consultants so you get it right from the word go.
2. Have a proper inspection regime during construction to ensure that your barrier is not compromised, especially by workmanship that is shady. Remember that testing failures can be expensive in terms of uncovering and remedial work that will be needed.
3. Be careful with dry lining. Plasterboard that is installed with dab and dot can prove problematic because missed leakage in bricks offer potential paths. You can consider using solid adhesive lines around board sides and socket cutouts.
4. Seal out supply and waste pipework around the building, especially where they penetrate the floors and walls. You can use compatible gunned sealants or pre-compressed flexible foam strips for gaps that are quite big. It is not advisable to use foaming adhesives because they shrink and break seal after test are completed.
5. Do not forget doors and windows because they are the culprits in leaking air. The frames should be fitted properly and sealed as appropriate. The best draught strips, sealants and seals should be used so there are no cracks and gaps around the lintels, sills and jambs.
6. Loft hatches and eaves cupboards also need to be attended to. Because they separate cold and unheated spaces from your living space, ensure that they remain properly sealed. The areas around light fittings are other commonly forgotten areas, yet they can lead to test fail. Seal the holes around the fittings and pull the cords in the ceiling. You might need to use air tight boxes over ceiling fittings around voids if you are not able to get fittings that are airtight.