Second, guttering prevents damage to the foundations. If water can freely run off the roof, it will pool at the bottom of the exterior walls, leading to puddles. Over time, these puddles with penetrate the ground and may get into the foundations. Again, a similar problem may occur: your foundations may start to weaken, leading to serious structural issues with your property. Putting foundations right is expensive and something that you want to avoid.
Third, guttering preserves your landscaping. Water run-off from your roof can erode soil and leave your landscaped areas looking a little worse for wear.
And finally, effective guttering discourages the buildup of mould by keeping water away from your walls and foundations. If water cannot penetrate your property, then mould cannot establish a foothold.