To build metal gutters for your home, you can make them yourself with sheet metal and some DIY know-how, or you can take the less time-consuming route and buy metal guttering pre-made. Making metal gutters will be much more expensive that purchasing them if you need to buy a metal brake and slip roller in order to do the bending. If you already have these tools, then your expense will only be in the sheet metal and needed parts like downspouts, elbows and hangers.
The most common application of home-made sheet metal guttering is to cover a leak or hole in existing gutters. If the gutter will be used to repair an existing structure:
Step 1 – Plan the Gutters
Aluminum is a good choice for gutters and is easier to work with than some other materials. It won't rust, but it will corrode. Occasional maintenance and awareness will prevent that and keep aluminum gutters working well for years. Standard gutters are 5", but areas with heavy rainfall and water problems could benefit from 6" gutters. Plan what you need so you know how much metal to buy and how complicated the project will be.
Step 2 – Cut and Mark the Metal
Mark the sheet metal where it needs to be bent to have a flat surface to mount against the fascia, or where it needs to bend to fit in with the existing gutters. For patching, make sure the piece of metal is big enough to cover the inside and wrap around the edges. It should also extend at least one inch on either side of the area to be patched. Use a template that you make from the end of your existing guttering to ensure you can bend the metal to the exact dimensions.
Step 3 – Create the Gutter Curve
Feed the sheet metal through your slip roller machine in order achieve the trough curve that makes up the gutter.
Step 4 – Bend the Metal
Put the piece of sheet metal into the clamp of your sheet metal brake so that a line you scratched is flush with the clamp. Close the clamp to hold the metal in place and then move the bending bar slowly to the proper angle as marked on the brake. Continue until you've bent the metal in the way that you need.
You may need to do this a few times in order to create the different bends that you need, particularly when matching it to existing guttering. Once the gutter is created, you can hang it as you would pre-made gutters.
Step 5 – If it's a Patch
If the piece you've bent is designed to repair your metal gutters, then spread roof cement inside the old gutter over the entire surface where the new piece of guttering will go to form a watertight seal. Press the new metal gutters in place. Then use pliers to bend the edges down over the old gutters to further secure it in place and use roof cement to coat the new piece, taking care to coat the edges well.