Gutters are an important part of the roof system on a home or building. Allowing rainwater to simply pour off the roof directly down the sides of a structure can compromise the walls, windows, and doors, plus ultimately the structural foundation. Understanding how to install gutters properly can be vital in protecting a home or building.
How to Install Gutters
Replacing old gutters on a home follows roughly the same steps as a first-time gutter installation. The biggest difference between the two when learning how to install rain gutters is the first step. The first decision is where to place the downspouts for a new drain system, and then make repairs. The remaining steps explaining how to install a gutter are the same.
The first thing that needs to be determined is how many downspouts are necessary. This can be the most important decision made prior to installing gutters. If there are not sufficient downspouts per linear foot of gutter, the gutters will overflow and permanently defeat their purpose. Determining how many downspouts is a two-stage process, which also involves taking into account where the water will go once it gets to the ground.
Calculate gutter size and the number of downspouts using a reasonable amount of rainfall per hour. Anything over a half an inch of rain in a 60-minute period is such a rare weather phenomenon; it is unrealistic to prepare for such a deluge. It is necessary to find the approximate square footage of each section of roof that will drain into a length of gutter. The commonly accepted practice is to place no less than one downspout for every 1,600 square feet of roof.
Where the water is going to go, is equally as important as how many downspouts are installed when determining how to install gutters. Homeowners need to be careful not to erode retaining walls, create drainage problems in a yard, or overflow retention ponds. The best place to aim a downspout is across a driveway or road, into a specially designed cul-de-sac, or out into an open area with good drainage capability.
Additional downspouts are better because they will handle more water during heavy downpours, plus disperse the water more evenly across the ground. Always err on the side of more downspouts if possible when determining how to install gutters.
Consider the Size of the Gutters
After positioning the downspouts, the next part of how to install gutters will be to figure out how wide the channels need to be. When deciding on gutter width, the roof dimensions will be used again. Normally, a total roof surface of 800 square feet or less, a 4-inch gutter is sufficient. For square footage between 1,000 and 1,200, the gutter width needs to be five inches. Ultimately use the maximum 6-inch gutters for 1,600 square foot of water runoff.
Planners frequently forget to take into account the type of roof material as well. This is an important part of how to install gutters to handle the speed of water coming off a roof.
Normal shingle roofs have a rough texture that slows down the flow of water. Slate and metal roofs are flat and smooth, so the speed of water coming off the roof is dramatically increased. When calculating the gutter width, add one size up in width for slate and metal roofs to compensate for the increased speed in which water will flood off the roof.
To be certain that the gutters will be able to handle an average rainfall runoff, the pitch of the roof also needs to be added to the equation. There are roof-pitch calculators, which provide a number added to the equation that includes the square foot of roof space. Presenting these numbers to a gutter supplier, or professional gutter installation company will guarantee the right sized gutter is purchased.
If the roof material and pitch are not accurately considered, the gutters will not be able to handle the volume of water. Just like not having enough downspouts, a gutter width that is too narrow to handle the amount of water runoff will basically render the gutters useless.
Hanging the Gutters
Now that the number of downspouts has been determined and the width of gutter picked, next step is to hang the gutters. When replacing old gutters, all nails, remove all hangers and hooks first. Fill any holes in the fascia with an all-weather Spackle. If the fascia is wood, paint it before hanging the gutters.
Once the fascia is prepped, the next series of steps are completed in order to hang the finished gutter. Any cutout for downspout holes, or attaching hangers, is easier when the gutters are on the ground. It will be much easier to do these things without having to balance on a ladder.
Things to Do When Hanging the Gutters
- Measure the length of the downspout for the section of overhang to be covered.
- Cut out each spot where the downspouts go.
- Mark the gutter slope by tacking a nail at one end of a section where the top attachment hole will be for the gutter. Measure up from the bottom of the fascia. Calculate in stretches equaling 10 feet and drop the end line point ¼ inch for each 10 foot of gutter length. To make it easier to align the cutter, use a chalk line to snap this line in place along the length of the fascia.
- This step is often skipped, but it can make attaching the gutter much easier. Align the back top edge of the gutter against the chalk mark on the fascia. Use a pencil to mark each anchor hole for the gutter. Set the gutter back on the ground and drill or punch a starter hole for each of the anchor screws. This will allow the anchoring screws to bite easier and the job of hanging the gutter will be much easier.
- Add sections to the gutter continuing across the roofline to the end where the downspout will be.
- Put the downspout angles together, except for any extensions needed at the bottom.
- Attach the downspout end to the underside of the gutter and tighten the holding screws.
As a final check, run water from the roof so that it drains down into the gutter. Check for leaks along the fascia, especially at the roofline. Use an all-weather grade of caulk to seal any places where water leaks back in behind the gutter.
How Much Does It Cost to Install Gutters?
The cost of gutters depends on the type of material. Galvanized and aluminum gutters are the most common and average between $4 to $9 per linear foot. Vinyl gutters are somewhat easier to install and are about half the cost of galvanized. There are vinyl gutter kits available that give detailed instructions on how to install vinyl gutters.
Wood gutters are rare, except when used to replace existing wood gutters on historic homes. Copper gutters have an essentially endless lifespan, but are the most expensive gutter material, averaging close to $20 per linear foot. These per foot costs are calculated using a standard number of downspouts, anchors and end clips. Additional downspouts, if necessary, will usually add around $10 to the total cost. Remember, those extra downspouts are far better than not having enough.
Homeowners who decide to install their own gutters can save on average $2,000 for a total gutter span of 200 linear feet. For additional length, calculate roughly $10 per foot.
Gutters are more than just a decorative addition to funnel water off the roof of a home. They keep the water from splashing back against the outside walls and windows to add longevity to the finish. Even more importantly, they keep water from pouring off the roof directly along the base of the home, compromising the foundation. If a house or building does not have gutters, it is strongly recommended by home professionals that they are installed. I hope our article on how to install gutters was helpful for you. If so, please feel free to leave a comment in the section below.