Oh no! The biggest fear that every straw bale home owner just came true! I smell mold. I think my bales are getting wet. I have high moisture readings on my in-place sensors. What do I do now? Well, the first thing, after you breathe and take a step back, is to find the cause of the moisture infiltration and fix it. Without that, anything else you do will be a waste of time.
Now that the problem has been fixed, it is time to get the moisture out of the bale walls. The first thought, depending on the extent of the damage, is to let the bales sit on their own and see how they do. If the moisture was not excessive, they may dry out on their own over time. If that does not work, you may need to drill some 1 1/2″ holes on the interior wall about every 2′ on center in both directions. Place a couple fans and a heater near the holes and drive hot air into the wall. This will move the moisture out.
If this does not cure the problem AND the outside air is not moisture laden, you may have extensive damage and may need to gut that section of wall. This is rare, and in most cases, the holes with the fans are the most extreme fix necessary. Again, the key is to find the source of the problem quickly and fix it. Everything depends on that.