One of our latest commercial projects had a very interesting find! During our quoting process we found that the building had been built on top of an old structure of tunnels. Since there was no way to tell what was under that and because the tunnels were so extensive we had to get creative. Our team created our own network of air flow to ventilate the tunnels below the building to reduce radon. Retesting is ongoing but we are excited to see how it turns out!