How to Install Rain Gutters How to Install Rain Gutters

What You'll Need
Gutter hanging straps
Extension ladder
Gutter sealant
Cordless drill
Duckbill tin snips
Hex head driver
Offset tin snips
Pop rivet gun
1 1/4" self-tapping hex head screws
1/4" hex head screws ('zippers')
1/8" rivets

Installing a new gutter system yourself can save you substantial money over using a professional contractor, but there are a few things to look out for and some hard work involved. Here we take you through each step from evaluating the project to installing downspouts.

Step 1 - Evaluate and Plan the Project

Inspect the soffit and fascia for any signs of rotted wood. You must have a flat surface to hang gutters to. Any bad wood must be replaced before you install gutters. If your house has crown molding or trim board nailed to the fascia, then you will need to remove this trim. Also, prime and paint any bare wood that will be behind the new gutter.

Draw a Sketch and Measure Your House

A man in a hardhat measuring a roofline for a gutter installation.

Measure each gutter run, and don't forget to measure for a downspout hole, or drop. When measuring for the gutter, always add one inch to each end of the fascia, which will allow water to drain off the sides of shingles on the edges of the roof.

Be sure to add up any outside or inside corners and end caps: one end cap for the left end, and one for the right end.

Measure the height of each downspout and add four feet for the extension away from the house at the bottom. Most downspouts will require three elbows. There are two types of elbows: one that turns to the front, which is an A elbow, and one that turns to the side, which is a B elbow. In most instances, you will only need A elbows, but occasionally you may need to turn the downspout extension sideways and for this, you will need a B elbow.

Planning Tips for Downspouts

Downspouts should be placed in unobstructed areas where they will direct water away from the house. They should not be installed in locations with obstacles such as meters or sidewalks.

On gutters that drain large roof areas, or if you live in an area with heavy rainfall, install oversized 3x4-inch downspouts on gutters. Gutters that are longer than 40 feet will need to slope down both directions from the middle and have downspouts installed on each end.

Step 2 - Cutting and Joining the Gutters

Put the gutters together on the ground because it's easier to cut and assemble the parts there than off a ladder.

Cut the Gutter

Using tin snips, cut the front and back sides at the appropriate mark for the length you need. Bend the sides down and cut the bottom. Straight snips work great, but you may find you are more comfortable with using left or right-handed snips. (You can purchase a three-pack at most home improvement stores for under $10.)

Preassemble Gutters

Gutter pieces are normally 10 feet in length. So, if the gutter run is over 10 feet, you will need to join sections together. Lap the seams at two to four inches, and then caulk and rivet them together. Use the same process for inside and outside corners. Always plan ahead so that you leave the best-looking factory cut on the outside. Also, be sure the inside section is facing downhill to prevent water from forcing out of the seam. Attach end caps with rivets and seal the joint on the inside with gutter sealant.

Step 3 - Adding Downspouts and Outlets

On the bottom of the gutter, mark the center of the downspout hole. Place the downspout drop or outlet with flange side down over the mark and trace around the inside. Use an old chisel to cut a V-shaped notch or use a drill and bit to create a starting hole. Place two pieces of short scrap wood, preferably 2x4s, under each side of the gutter. The wood will help support the gutter while you cut the hole. This is where left or right-handed snips come in handy. Use the pair of snips that will cut the easiest and cut out the hole for the outlet.

Step 4 - Proper Slope

Drive a nail 1/2-inch below the shingles on the high end of the gutter run. Measure the distance from the nail to the bottom of the fascia board. For every 10 feet of gutter run, subtract 1/4 inch from this measurement. Mark this distance on the low end of the gutter run and drive a nail there. Stretch a chalk line between the two nails and snap the line. You can use a level and align with the string to check for proper slope. The bubble in the level should be off-center on the high side. If it isn't, adjust your chalk line until the bubble shows that you have the proper slope.

The number and size of downspouts determine how fast your gutters will empty. Sloping them helps eliminate standing water that can cause corrosion and leak through the seams. Slope each gutter run down toward the downspout about 1/4 inch for every 10 feet of a gutter. If your fascia boards are level, you can use them as a reference for sloping the gutters. Check this by holding a level against the bottom edge. If they are not level, adjust the string line until a level aligned with it shows a slight slope. Snap a chalk line to indicate the top of the gutter. Then straighten gutter sections as you screw them to the fascia by aligning the top edge with the chalk line. Once you have your line, you can now hang the gutter section.

Step 5 - Install the Gutters

Install hidden hangers every two feet to strengthen the front of the gutter and support them. Once hangers are in place, you can attach the gutters. If you have someone to help you, you both can be on each end and hold the gutter in place with your snapped line on the fascia. Then, starting on the high end, screw in each hanger to the fascia board. Work your way from high end to low end, keeping the bottom of the gutter in alignment with the snapped line.

Someone hanging gutters on a roofline.

If you are doing the job by yourself, then start in the middle and align the center of the gutter with your snapped line and screw in two or three of the hangers to the fascia so that the gutter will stay suspended in place. Then you will go to the high end of the run and start screwing in the hangers. Make sure your gutter stays aligned with the snapped line and work your way toward the middle. Once you are back at the middle, you may have to unscrew those hangers and readjust the gutter with your line. Keep working down from the high to low end, screwing in all the hidden hangers. Once all hangers are attached, the gutter is not going anywhere and you are ready to install the downspouts.

Step 6 - Installing the Downspouts

Take an elbow and screw it to the downspout outlet on the gutter. Hold another elbow against the wall of the house and measure the distance between, allowing for a 1-1/2 inch overlap at each end. Cut the proper length with a hacksaw from the end of the downspout that isn't crimped in.

Attach the elbows and downspout tubing with the crimped ends facing down. Use sheet metal screws so that the downspout can be disassembled for cleaning, if necessary. 1/4 in-hex screws are ideal for attaching downspouts. (They can be found in most home centers in the aluminum siding section. They are also commonly known as zip screws and are easy to install.) Downspouts are easy to cut with a hacksaw. Be sure to wear protective equipment when cutting.

Every elbow and length of gutter used will need to be crimped or squeezed on one end to allow the pieces to fit one inside the other. You can use your hands which is not so easy, or you can use a pair of needle nose pliers to crimp the ends. However, to save time and frustration, you can purchase an inexpensive crimping tool that will do the job fast and easy.

Once all downspout pieces are fitted together, attach the downspout to the house with straps. U-shape straps are best, but you can also make your own out of scrap gutter pieces. When attaching the downspout to the house, be sure the seam of the downspout is facing the house. This is an eyesore you don't want to have after all the hard work you have done. Depending on the height of the downspout, you want at least two straps holding the downspout in place: one strap about a foot from the top elbow and one strap a foot or so from the bottom elbow. If the downspout is over 10 feet, consider adding another strap in the middle. Make sure the downspout is securely fastened and will not move.

Gutter Maintenance

Gutters filled with leaves.

Once you have your new gutters installed, you can extend the life of your gutters and eliminate many problems by keeping the gutters free of debris. Clean the gutters at least twice a year, or hire someone who specializes in cleaning and maintenance.

Got a New Project You're Proud of?

Post it on Your Projects!