Air Sealing near you

This is the section that distinguishes a competent Australian air sealing job from a damaging one, and it is the part that a guide written for another country gets wrong.

Energy Safe Victoria describes how an open-flued space heater draws air from the room to feed the fire and directs combustion products outside via a flue, and how factors such as wind or the use of appliances including bathroom exhaust fans can lower the air pressure inside the room and create a negative pressure environment in which airflow through the flue may become restricted or in some cases even reversed. It adds that if the supply of fresh air to the burner is interrupted, the flame will produce high levels of carbon monoxide.

Air sealing pushes a house in exactly that direction. Every gap closed reduces the building's ability to make up the air that a flue, a rangehood or an exhaust fan is removing, and a house that was marginal before can become one that spills afterwards. The correct response is not to leave the house leaky but to treat the two as one project: seal deliberately, provide ventilation deliberately, and have the gas appliances tested afterwards.

That testing belongs with a licensed gasfitter. Energy Safe Victoria states that gasfitters are required to test heaters during installation and servicing to ensure they do not spill combustion products and that any exhaust fans do not affect the heater, and that carbon monoxide testing is part of a comprehensive service. Tell the gasfitter that the house has been sealed, because it changes the conditions the test needs to be carried out in.

Autumn is the natural time in the southern states, because the benefit shows up immediately in the heating season and because the work is comfortable to do. Roof space work in particular should be booked outside summer: an Australian roof space under a dark roof in full sun is a genuinely hazardous place to spend an afternoon, and nobody does careful sealing in those conditions.

The benefit is not only a winter one, which is a point often lost. In summer, uncontrolled air movement brings hot outside air and roof space heat into the house and undoes the work the air conditioner is doing, so a sealed house holds its cool for less energy. During a smoke episode, a sealed house is the difference between closing up and actually keeping the smoke out, and it is what makes portable filtration effective. In pollen season the same applies.

The one seasonal caution is to seal and ventilate in the same project rather than in different years. A house sealed in autumn with no thought given to moisture will show condensation by mid-winter, and the household will conclude, wrongly, that the sealing was a mistake.

Air sealing is unusual in that the cheapest items often deliver the most. Sealing a manhole, fitting proper door seals and dealing with redundant vents costs very little. Costs rise with the number of downlights and penetrations to be addressed, whether an electrician is needed for the ceiling fittings, whether window hardware and seals are being renewed, whether any testing is included, and whether ventilation work is part of the same scope, which it should be.

LokalMatch is where the job starts, not where it ends. Describe the house, its age and construction, the draughts you notice and where, any gas appliances and your postcode, and building, insulation, ventilation and gasfitting businesses covering your area contact you directly; those businesses pay LokalMatch for the requests they receive. LokalMatch does not do the work, does not set or quote prices and does not vet, rank or recommend anyone, so ask what will be deliberately left open and why, and have gas appliances tested after the work.