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If you’re trying to be “water-wise,” you’ve probably considered installing a rainwater harvesting tank. These easy DIY projects are effective in living “greener,” but have you considered how to cut the downspouts to fit into the tank?
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How To Cut A Downspout
Downspouts are vertical pipes essential for directing rainwater from the gutters into the ground (or into a tank) away from the building and often have legal recommendations.
Their construction makes them relatively easy to cut with simple tools, including tin snips, hacksaws, and angle grinders.
| Tools | Recommended Use |
|---|---|
| Tin Snips | For square or rectangular metal downspouts already in position |
| Hacksaw | For metal and PVC downspouts connected to a wall, if not, you need to stabilize it |
| Angle grinder | Any type of spout connected to a wall, if not connected, secure/clamp it on the table for straight cutting |
| Circular saw | Spout needs to be uninstalled and cut using a circular saw with a guide (e.g. two planks) |
| Jigsaw | Tricky to use but works like a circular saw that needs a guide |
Step One: What Type Of Downspout You Have/Want?
Downspouts come in different styles, materials, and dimensions. Before we cut these pipes, we need to know what we’re dealing with.
There are two downspout categories:
- Round
- Rectangular/square
There is some diversity within these categories, and there are several different materials used in their construction, including:
- Aluminum
- Copper
- Steel (galvanized and stainless)
- PVC
- Vinyl
- Wood
- Zinc
Downspouts range from 3 to 5″ (diameter), or 2×3, 3×4, and 4×5″. The size, shape, and type of material influence how we cut a particular downspout.
Step Two: Measure And Mark Where To Cut
The next step is to measure where the downspout will run from the gutter to the ground. You’ll need to decide if your pipe goes straight down or needs to bend.
Once measured, mark off the area you’ll cut with a marker pen or pencil. You’ll need to ensure the line is straight, so use a T-square or ruler for square/rectangular downspouts. It’s important to mark around the spout (on all four sides); otherwise, you may cut skew.
When drawing a line around the circumference of your round downspout, measure to the point you want to cut, make the mark, then wrap the measuring tape around the pipe to give you a straight guide to trace. Alternatively, you can stick tape around the pipe as a mark.
Step Three: Cutting The Downspout With Tin Snips
While you can use several different tools for cutting downspouts, one of the simplest ways to cut square or rectangular pipes is with a pair of tin snips, particularly if your downspout is a type of metal already in position.
You can also use tin snips in cutting aluminum siding and trimming copper sheets for your DIY projects. But here’s what you need to do when using tin snips for your pipe.
You’ll need a “left-handed” and “right-handed” pair of tin snips (the bottom blade is on the left and right, respectively).
Start at the end of the pipe and cut down to the line (if your line is close to the end of the pipe). Once at the line, cut along the side until you reach the corner.
Turn the pipe and continue cutting until you complete the circle.
If you’re cutting further away from the end of the pipe (i.e., you can’t cut from the edge of the pipe to the line with the tin snips), you’ll need to make an incision along the line.
Using a utility knife, make a perpendicular incision (roughly 2″) close to the line on the part of the pipe that you’ll discard. Next, insert the tin snips in the incision and cut a circle, first away from the line, then moving back toward it.
Once on the line, you’ll cut two lines around the pipe (one with the left-handed blade, the other with the right-handed blade). You’ll cut out a roughly 2” middle band between the two lines, bending it up as you cut.
This band allows you to cut the downspout without bending it/provides enough space for the tin snips.
Using A Hacksaw To Cut Downspouts
Another fantastic tool for cutting these pipes is a hacksaw. Many DIYers prefer using hacksaws as they offer considerable control, and you can cut a spout “in situ.”
You may need a combination of hacksaw and tin snips if the pipe is connected to the wall.
When using these saws, you’ll need to stabilize the spout. The less movement, the better; however, simply holding the spout with your free hand is usually sufficient.
Using the saw, make a superficial cut on the line. Once the saw has “bitten into” the pipe, press harder. Hacksaws have forward-facing blades that only cut on the “push” stroke.
As you cut, turn the pipe accordingly (when applicable). If the downspout is already installed, cut the front section of the pipe as far as possible. Then finish the job with your tin snips.
Step Four: Neaten The Cut
If your measurements were accurate, and you cut straight along the line, you should have a neat cut.
If not, you can trim any extra pipe with the tin snips. Alternatively, you can sand down rough edges with a file/sandpaper.
Using Power Tools To Cut Downspouts
For those who don’t enjoy manual labor and who have access to power tools, you’ll be pleased to know that they are great for cutting round or square/rectangular pipes, provided you have the correct blade.
Using An Angle Grinder To Cut A Downspout
The most versatile of tools, an angle grinder is perfect for cutting wood and even spouts.
Start by marking off the area you want to cut. Next, place the pipe on an elevated platform with enough clearance for cutting (the edge of a table works well, otherwise, place a piece of rigid foam underneath the spout).
Clamp/secure the spout to the table to ensure it does not shift while you cut. You can now begin cutting along the line, turning the downspout as often as required to follow the line.
While many experienced operators are happy to cut free hands, you may elect to use a guide to help you cut straight.
Once cut, take the edge of the grinder to neaten up the cut edge.
The best about an angle grinder is that you can generally cut a downspout, even if it’s already attached to a wall, thanks to its various cutting positions.
Using A Circular Saw To Cut A Downspout
A circular saw is not typically used for downspouts; however, they will work in a bind. The spout needs to be uninstalled, and you’ll need to construct a type of guide.
The easiest method is to take two straight wooden planks of equal size. Place them on the sides (so that the wide face is vertical) and sandwich the pipe between them.
Depending on the size of the spout, you may need to place a plank spanning across the two holding planks. Ensure the downspout is marked, and place the circular saw in line with the mark. Like when cutting a thick wood with a circular saw, you need a stable set-up.
Cut from outside the plank, through the plank, into the pipe, and through the other plank (you might need to pre-cut the planks with a different blade). Adjust the pipe accordingly and repeat the process.
Alternative: Using A Jigsaw
You can follow the same steps as the circular saw if you have a quality jigsaw. However, they are equally tricky to use, and you should know how to use a jigsaw to achieve a flawless output. You’ll also need to place a plank across the top of the guide.
With any power tool, the correct blade is essential to the success of the cutting. While most DIYers won’t use a circular saw or jigsaw, an angle grinder is often practical. However, with power tools, you always run the risk of cutting skew, so take care while cutting and do so patiently.
Frequently Asked Questions
What Safety Equipment Do I Need For Cutting Downspouts?
Although safety equipment varies depending on the tool used, when cutting downspouts, you’ll need gloves, eye protection, a dust mask (if using power tools), and long-sleeved clothes (not loose fighting) to prevent cutting yourself on sharp edges.
Can I Cut All Downspouts With The Same Tool?
Unfortunately, one tool is often not sufficient for cutting all downspout types. While tin snips are essential for aluminum and other soft metal downspouts, you’ll need a hacksaw for other materials. An angle grinder is practical but may tear softer metal.
Conclusion
Most DIYers manually cut downspouts with a good hacksaw and two pairs of tin snips. While an angle grinder is an effective tool, it might damage softer metal pipes. Accurate measurements and a steady hand are essential when cutting downspouts.
