The gutters should be cleared out regularly and any leaks repaired where necessary to help prevent dampness and damp penetration occurring, which can lead to other problems within the building, such as deterioration of masonry.
Surveyors normally find that most old metal rainwater fittings are leaking to some degree and in a lot of cases are corroded, meaning they often require replacement. As mentioned above, leaks can cause significant damage. Replacing fittings with PVC can however detract from the aesthetics of the property, particularly with regard to period property.
Surveyors report that a lot of movement in buildings can be caused by downpipes that do not allow water to drain away properly. A high concentration of water in a localised area can cause the soil beneath foundations to erode away leaving the structure of the wall unstable. This is quite common where water butts are used, often for conservatories and they are left to overflow. A conservatory normally has quite shallow foundations that can be easily influenced by movement beneath.