Dry rot is a fungus that destroys wood. Dry rot can be prevented by controlling moisture. Our houses all inevitably are exposed to moisture which can cause dry rot over time. Some of the biggest causes of excess moisture are condensation, invisible leaks, poor drainage, overflowing rain gutters, cracked roof tiles, standing water in kitchens and baths, sprinklers hitting your home etc. Dry rot softens the wood which is bad enough, but then it also attracts termites who love to eat soft wood.