To detect leaks, the building’s frame must be fully exposed, with all coatings, cladding, and drywall removed. The floor slab has been poured. The HVAC penetrations in the roof have been completed and sealed. The best time to detect leaks is usually after the framing contractor has finished its work.
To detect leaks, all penetrations must be fully installed and sealed (ventilation ducts, range hoods, chimney flues for fireplaces and sauna stoves, water pipes and sewer lines, central vacuum system discharge pipes, and floor penetrations such as conduits for electrical wiring or geothermal heating pipes, etc.).
The following installations must be completed before leak detection:
Exterior doors and windows
- The exterior doors and windows have been installed (the front door does not need to be installed).
- 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 fireplace 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
- 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.
- If a garage is attached to the building and shares the same ventilation system, an exterior door must be installed. If the garage has its own ventilation system, a door between the dwelling and the garage must be installed.
Before measurement:
- Close all windows and doors carefully.
- Do not heat the fireplace for about 24 hours before taking the measurement.
- 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.