If you are building a new home, renovating an existing one, or simply replacing an old, dilapidated gutter system, you are likely curious about the overall costs. Fortunately, you can estimate for yourself the cost of a gutter installation by taking the proper measurements and looking at the prices for gutter materials. Here are some tips and tricks for getting a rough estimate of the cost of your installation.
Calculate the Drainage Area in Square Feet
First, you will need to know the square footage of your gutters’ drainage area. For a gable-end roof, this is simple. Just multiply the length by the width for each side. If you have hip roofs or intersecting roofs, you will need to calculate the area of each section by measuring length by width. Each section will then become its own drainage area, so keep this information handy, but add them all together to determine how many feet of gutter you will need.
Pitch and Rainfall Measurements
Now that you know you need X length of the gutter for your home, you will need to calculate the number of downspouts and the size of the gutter. To do this, you will need to account for your roof’s pitch and your area’s maximum rainfall intensity.
- To measure pitch, use a two-foot level and a simple tape measure. Hold the level against the roof, level it out, and then measure the distance from the underside of the level at its very center to the top of the roof. The number of inches between the level and the roof shows the pitch, and you can use this information to find your standardized roof-pitch factor.
- To measure rainfall intensity, check out this table from the US Weather Bureau. It is an accurate record of the maximum rainfall your location might receive in a five-minute period, and you will need this information to properly size your gutters.
Obtaining Gutter Size
With all the information above in hand, you can go about finding the right gutter size. First, multiply the total drainage area by the roof-pitch factor and rainfall intensity. This provides an adjusted square footage that your gutter system must account for. Different types and sizes of gutters are ideal for different scenarios.
- K-Style: A 5-inch K-style gutter is ideal for adjusted square footage totals of 5,520 square feet. A 6-inch K-style gutter is required for totals higher than this up to 7,960 square feet.
- Half-Round: A 5-inch half-round gutter is ideal for adjusted square footage totals of up to 2,500 square feet. A 6-inch half-round gutter is required for totals higher than this up to 3,840 square feet.
Once you are aware of how much gutter you need, the right size, and the right style, you can begin to price the materials online. For even more help, feel free to contact local contractors near you who may be willing to perform these calculations on-site and offer free estimates for their labor, as well.