The purpose of the rain gutter downspout is to redirect water from the rain gutter into proper drainage. Installing a downspout is probably the last item that a person will do when installing a rain gutter. It is important that the downspout is of the correct length to catch rainwater.
Step 1 - Measure the Length of the Downspout
Measure the distance from the drain point of the rain gutter to the ground. When measuring, be sure to start from the ground and end at the flat of the gutter. Subtract 6 to 7 inches and this will become the length of the downspout.
Step 2 - Cut the Downspout
Placing the measuring tape on the downspout, make a mark with permanent marker on both ends. Place the measuring tape on the downspout again but this time deducts 2½ inches away and mark the position. Measure again and deduct another 2 inches. Repeat this action for both sides of the downspout.
Using a hacksaw, follow the areas where it is marked and saw accordingly. This will end up with a downspout with a diagonal end.
Step 3 - Attach the Downspout to the Gutter
Apply sealant around the mouth of the connector and raise it to the gutter. Both the connector and the gutter should not have any water on them. Using 6 rivet screws, screw the connector to the gutter. Apply sealant again on the connector on the outside after that to ensure no leakage occurs.
Step 4 - Attach the Elbow
Attach the elbow to the connector piece using self-tapping screws. Make sure that the elbow is pointing to the ground. The downspout at this time should be leaning against the wall. Attach the other elbow to the lower end of the downspout. This elbow should be in a sloped position. Then attach another elbow that points to the ground.
Step 5 - Attach the Lower End of the Spout
Attach the lower end of the downspout to the elbow. The downspout should not be touching the ground. Cut the downspout if it really touches the ground.
Step 6 - Attach the Metal Straps
The metal strap presses the downspout against the wall so the downspout won’t wobble in the event of high wind. Make sure to attach the straps every 10 feet. Screw the metal straps to the wall. There might be a need to drill holes for the screwing of the metal straps.
Step 7 - Attach the Last Elbow
Attach the last elbow to the downspout, making sure that this elbow faces the drainage system. Test it by pouring a large volume of water and making sure that no parts of the spout leak.
When using the hacksaw, use common sense and be careful. When attaching the elbow and the downspout, be careful. The corners of the mouth of the elbow and the downspout are extremely sharp, especially if they are made of copper.