For the airtightness test, the building’s airtight envelope (ground floor, walls, roof) must be complete, the doors and windows must be installed, and all penetrations must be complete and sealed (ventilation ducts, range hoods, chimney flues for fireplaces and sauna stoves, water pipes and sewer lines, the central vacuum system’s discharge pipe, base floor penetrations, such as conduits for power supply or geothermal heat pipes, etc.).
The measurement can be performed even if one door has not yet been installed or is still being used during the construction phase. In this case, the door opening must be less than 1 meter wide and have jambs or a frame to which the mounting structure for the measurement door can be attached.
If a garage is attached to the building, an exterior door must be installed.
The air/vapor barrier should still be visible so that any potential leaks can be easily repaired. However, this is not necessary.
The ventilation unit does not need to be installed. It is easier to take the measurement before the ventilation unit has been installed.
The following installations must be completed before the measurement:
Exterior doors and windows
- The joint between the window and door jambs and the exterior wall has been sealed with urethane, tape, a sealing strip, or a suitable sealing compound.
- The door sills have been sealed.
Ground floor
- Pipe penetrations have been sealed to the floor using urethane or a suitable sealing compound.
- The joint between the base floor and the wall has been sealed. (An effective but not mandatory practice is to cut a groove in the surface of the concrete and then apply a suitable sealant to the joint between the wall and the base floor.)
Roof
- The seams of the roof air barrier (air barrier paper, vapor barrier plastic, or urethane panels) have been thoroughly sealed and connected to the exterior wall’s barrier in an airtight manner.
- The supports for the roof structure have been installed. The measurement will be conducted under increased negative pressure, which could damage an unsupported roof air barrier.
- The pipe penetrations have been sealed with collars and vapor barrier tape to the roof air barrier.
- The chimney flue has been sealed to the roof air barrier.
Walls
- The air barrier in the walls has been sealed throughout.
- Penetrations through the exterior wall (such as the fresh air duct for the ventilation unit, the discharge pipe for the central vacuum system, and electrical conduits) have been sealed with urethane or a suitable sealing compound.
- It is a good idea to perform the airtightness test before painting and filling work, or a few days afterward.
Other things to note
- The block walls and chimney have been fully lined on the inside (including the basement and utility room walls). A block wall or flue that has not been lined will allow air to leak, which will compromise the measurement results.
- It has been ensured that the building envelope’s air barrier is continuous in areas containing wet rooms, saunas, or utility rooms. The waterproofing must be complete and tightly connected to the building envelope’s air barrier.
- Temporary openings created for the construction phase and any other holes in the building envelope have been sealed.
- Standard mains power is available in the building.
- In the case of semi-detached houses, the openings between the units must also be sealed.
- Buildings with two or more floors: Ladders must be provided between the floors so that the person conducting the measurements can access all floors from inside the building.
- Roof safety equipment must be in place, as the person conducting the measurement may need to seal the chimney flue or some ventilation ducts from the roof.
Before measurement:
- Close all windows and doors carefully.
- Do not heat the fireplace for about 24 hours before the measurement, because the person conducting the measurement will seal the flue with tape or a rubber sealing ball.
- If the building is cold, turn on the heater 24 hours before the measurement, for example. The goal is to create a temperature difference between the interior and exterior so that the leak points can be detected using a thermal imaging camera.
- Move construction supplies, furniture, and other movable items that you can reasonably relocate to a distance of about 1 meter from the wall to facilitate leak detection.
- Provide sufficient general lighting for the building to ensure visibility during the measurement.
During measurement:
- Set aside 3–4 hours for the measurement. Other work can continue for most of this time.
- It is recommended that a carpenter be on site to handle any necessary repairs.