For the tightness measurement, the building’s airtight envelope (base floor, walls, roof) must be complete, the doors and windows must be installed and all lead-throughs must be complete and sealed (ventilation ducts, extractor hood, fireplace and sauna stove flues, water pipes and sewers, central vacuum system’s discharge pipe, base floor lead-through pipes, such as shield pipes for power supply or geothermal heat pipes, etc.).
The measurement can be conducted even if one door is still uninstalled or has door used for the construction phase. In this case, the door opening must be less than 1 metre wide and have jambs or a frame to which the framework for the measurement door can be installed.
If a garage is connected to the building, the external door must be installed.
The air/vapour barrier should still be visible so that any possible leaks can be easily repaired. This is not necessary, however.
The ventilation unit does not need to be installed. It is easier to conduct the measurement when the ventilation unit has not yet been installed.
The following installations must be complete before the measurement:
External doors and windows- The settlement clearance gaps above doors and windows have been sealed with tape at least on the inside.
- The joint between the jambs and bucks has been sealed with tape.
- (Not mandatory: at the position of windows and doors, the joints between the bucks and logs have been sealed with tape/suitable sealing compound.)
Ground-supported tile- Pipe lead-throughs have been sealed with urethane/suitable sealing compound to the floor.
- The foundation strip is fully compressed between the log and cast concrete, and any gaps have been sealed with urethane from under the strip. (An effective but not mandatory practice is to cut a foundation strip in the surface of the casting and then apply suitable sealing compound on the joint between the wall and base floor.)
Ventilated base floor- The air barrier plastic or paper has been sealed to be consistent across the seams and taped to the log wall with two-sided tape. A fastening batten has been installed on top.
- The lead-through pipes have been sealed to the floor’s air barrier plastic or paper with sealing collars and vapour barrier tape.
Roof- The air barrier plastic or paper has been sealed to the log wall with two-sided tape and a fastening batten has been installed on top.
- In the case of inclined roofs, the log seams have been sealed with urethane/suitable sealing compound.
- The supports for the roof structure have been installed. The measurement will be conducted at boosted negative pressure, which may damage an unsupported roof air barrier.
- The pipe lead-throughs have been sealed with collars and vapour barrier tape to the air barrier paper or plastic.
- The fireplace flue is sealed to the air barrier paper or plastic.
Walls- Any possible power cable channels inside the log wall have been sealed with urethane/suitable sealing compound preferably from the outside (so that the channels are not filled with cold in winter, which would cool the wall structure).
- Lead-throughs that go through the exterior wall (ventilation unit’s fresh air duct, central vacuum system’s discharge pipe, electrical pipes, etc.) have been sealed with urethane/suitable sealing compound.
- Ensure that the log framework has been tightened before measurement.
- It is a good idea to conduct the tightness measurement before painting and filling work or a few days thereafter.
Other things to note- The block walls and chimney have been fully faced from the inside (including basement and technical room walls). A block wall/flue that has not been faced will leak air that will deteriorate the measurement result.
- It has been ensured that the envelope air barrier is uniform at the position of wet rooms, saunas or technical rooms.
- Temporary lead-throughs for the construction phase and any other holes in the envelope have been sealed.
- Regular mains power is available in the building.
- In the case of semi-detached houses, the lead-throughs between the housing 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 fireplace 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 measurement.
- If the building is cold, turn the heater on 24 hours before the measurement, for example.
- Move construction supplies, furniture and other movables that you can reasonably relocate to a distance of about 1 metre from the wall to facilitate leak detection.
- Arrange sufficient overall lighting for the building to ensure visibility for the measurement.