‘The beauty of life is found in all of these subtle imperfections’

Radon mitigation worked much better than expected in the end. Because of our house’s rather particular construction (wood foundation, two levels of basement, no way of venting from the lowest level), the installers were unwilling to make any guarantees about radon levels post-mitigation, but they needn’t have worried. Before installation we saw an long-term average of 550 Bq/m³ in the basement; levels currently hover in the single digits, sometimes a bit more if it’s raining, sometimes even zero. It’s the nature of radon that levels fluctuate a lot (before installation we saw levels under 200 and over 800), so the point is to look at the long-term averages, but regardless levels are now well under Health Canada’s do-something-about-it guideline of 200 Bq/m³. Mark as solved. They installed the unit in our bedroom closet, opting for a slightly more powerful model that was still able to pull air from the lower basement level. It does make a bit of noise, so I’ve thrown an old winter coat…