by Allison Bailes
That photo above is from my basement. In case you missed my last blog, I just bought a 1961 ranch-style house in Atlanta and am embarking on the wonderful building science adventure of turning it into a high-performance home. Ultimately, I'd like to take it all the way to net zero energy, too. My father-in-law, who sold us the house (Thanks, Stewart!), had some work done to improve it several years ago, so that water spot you see above is dry now. It just looks really nasty.
Until this week, though, I didn't know what the source of moisture was that created the spot. Was it rainwater from outdoors leaking in through a penetration in the band joist? Was it a plumbing leak from the nearby kitchen? Was it groundwater climbing up the foundation wall by capillary action and finding an opening at this location?