1 in 5 Canadian homes has high radon. Find out if yours does — for free.

It is a radioactive gas that forms when uranium in soil and rock breaks down. You cannot see it, smell it or taste it, and it is in every building to some degree. Outdoors it disperses harmlessly. Indoors it can build up, and long-term exposure to a high level raises the risk of lung cancer — Health Canada identifies radon as the number one cause of lung cancer in people who have never smoked.

Yes. We place a professional continuous radon monitor in your home for two to seven days, collect it, and give you the result — at no cost and with no obligation. If your number comes back low, that is the end of it. We would rather you know your number than not.

The free short-term test uses a continuous monitor that sits on the lowest lived-in level of the house for two to seven days. It gives a first reading in about ten minutes and a result within about 24 hours of pickup. A long-term test runs 91 days between September and April, and Health Canada is clear that a long-term result is what a mitigation decision should be based on.

Health Canada's action level is 200 becquerels per cubic metre (Bq/m³), and the World Health Organization's reference level is 100. There is no threshold below which radon is known to be harmless — the risk falls as the level falls — so the guideline is a point for action, not a line between safe and unsafe.

Fall and winter. A closed-up, heated house has the strongest pressure difference pulling soil gas in and the least fresh air diluting it, so that is when levels peak and when a reading is most representative. November is Radon Action Month in Canada for exactly this reason.

Most residential installations are done in a single day. Health Canada notes that a properly installed system reduces radon by more than 80% in most homes. Older foundations, stone basements and houses without usable sub-slab drainage take longer, because the diagnostic and sealing work comes first.

It changes almost everything about the fix. Much of the Halifax region sits on granite and slate, and both carry uranium. Bedrock is also fractured, so instead of gas diffusing evenly up through soil, it travels along fracture planes and arrives at whatever opening it meets — often a rock ledge left exposed in a basement corner, a gap around a foundation wall, or the joint where a slab was poured against stone. The practical consequence is that a single suction point in loose gravel, the textbook approach, may not connect to the path the gas is actually using. Diagnostics matter more here than they do on the Prairies.

Yes, and older stone and rubble foundations are common enough here that the approach is well understood. The work is different from a modern slab, though. A dirt or partial floor, a rock ledge, or a fieldstone wall all leak across a large area rather than at a few cracks, so the first step is usually sealing and membrane work to create a surface that can actually be put under suction, followed by a depressurization system sized for that. It takes longer than a one-day job on a poured slab, and the diagnostic work up front is what determines whether it succeeds. What it is not is impossible.