Downspouts are the vertical lengths of piping attached to the sides of a home. They connect to the gutters that run vertically along the roof so that runoff water can be carried off the roof and safely away from the home, preventing damage to the structure and surrounding foundation. Downspouts are sized according to the quantity and velocity of runoff water needed to be eliminated from the home, and are generally constructed out of a material such as metal or vinyl, but can also be constructed out of wood.

When performing routine maintenance on downspouts, the following should be considered:

• • All trapped debris should be removed from the downspout, using a plumber’s snake or garden hose that has been modified to spray water at a higher pressure. When cleaning, avoid being too rough, as the downspouts could pull away from the gutters or walls. Periodic cleaning, particularly during the fall, is highly recommended since most debris consists of leaves, twigs, and other organic matter which will break down into earth. This earth, then, becomes firmly compact and much more difficult to remove then loose leaves and twigs. To reduce the amount of debris that collects in gutters and downspouts, mesh coverings or leaf guards can be installed over the gutters and downspout outlets. However, it is important that installing these coverings do not result in other problems, such as reducing the amount of water they must accommodate or trapping vermin in the drainage system. It is recommended homeowners explore the several types of guards on the market today, and that they shop around for the guard best suited for their home.

• Downspouts should be connected securely to the gutters. If screws or pop rivets are used to connect a downspout outlet to a gutter, make sure these are tightened and silicone sealant forms a waterproof seal. If a gutter drop outlet is used, ensure it is also connected to the gutter with a waterproof seal.
• Check the fascia boards, whether they are flat or angled. Fascia boards run along the roof eaves as an edge and hide the rafters for aesthetic purposes. Since gutters and downspouts are normally attached to these boards, it is important that they are not damaged to provide a strong base for the attached drainage system.
• Sections of downspout piping must be connected securely to each other. The tapered ends of piping fit inside the non-tapered ends, and are fastened together with screws. Tighten these screws if necessary, or add more. Make sure that the screws which are used do not protrude too much into the downspout, as this will catch falling debris and result in clogs. Anchor straps attaching the downspouts to the wall should be secure, one placed ideally every six feet.
• Rust and damaged downspouts should be replaced or fixed.
• Elbows should be angled properly to maintain efficient dispersal of runoff water.
• Once runoff water reaches the end of a downspout, it should be directed well away from the property by a splash block, underground drainage system, or connecting downspout extender. Common in North America, splash blocks and downspout extenders are inexpensive but effective ways to eliminate runoff water.

Following this checklist during routine maintenance will ensure proper drainage of runoff water from your home. Please see the page Gutter Downspout Extender Maintenance for more information.