What is the Purpose of a Starter Shingle?

Disclaimer: Please use caution when working on sloped roofs. If you have any concerns or are not trained to work at heights, hire a trained professional.

starter shingle

Every roof has to start somewhere, and that somewhere is at the appropriately named starter shingle (also called starter strip). Starter shingles are the initial shingle products installed on the roof, just before the first course of the finish shingles, which will comprise the visible parts of the roof.

Since the starter shingles will be covered by the roof shingles, it doesn’t matter what color they are, (except in special situations — see below). Consequently, starter shingles are generally covered with natural, darker, uncolored roofing granules. And they’re usually a generic rectangular shingle shape, so they can be compatible for use with any overlying shingle style. Otherwise, they are essentially made the same as any other fiberglass-reinforced, asphalt shingle.

IKO’s starter shingle product, Leading Edge Plus, offers the latest evolution in roof starter strips. Professional contractors who make the smart decision to use them will find they save time, are easy to install and are consistently sized. Each Leading Edge Plus starter strip “shingle” is perforated right down the middle so that you get two starter strips out of each roof shingle.

Now that we’ve described what starter shingles are, let’s answer a few of the common questions about their installation and purpose.

  • Where do they go?
  • Where do the nails go?
  • Isn’t it just an upside-down shingle?
  • Do they have sealant?
  • Length and coverage considerations.
  • Special situations.

Where do they go?

Historically, starter strip shingles have been used not only at the lower eave edge of the roof, but experienced professionals also use them at the gable, or rake edges of roofs. At the eave, the starters provide a simple way to “cover” the joints between the finish shingles in the first course, ensuring complete water-shedding roof coverage. As well, starter shingles have a sealant strip, and, when positioned correctly, the sealant strip will be on the top surface and at the lowest edge of the roof.

roof edge showing starter shingle over underlayment

At the roof’s rake edges, the starter doesn’t necessarily perform that joint-covering function it performs at the eave, but it is integral in the roof’s overall wind resistance. At the rake, the sealant strip will be positioned at the outer roof edge and once warmed by the sun, it will help seal the rake ends of all the finish roof shingles. A simpler and very useful purpose for using starter shingles along the rake edge is that it gives the installer a nice straight line to use as a guide when ending each course of the field shingles. So, when observers look up at the roof gable ends, they’ll see an aesthetically pleasing uniform line rather than ragged and uneven shingle ends.

Whether installed at the eave or the rake, the starter shingles should overhang the edge of the roof by ¼ inch to ¾ inch. Typically, the finish shingles are then installed to align with the edge of the starters.


Where do the nails go?

With traditional three-tab shingles, nail location is pretty straightforward — most often defined as “above each cutout, just below the sealant.” With conventional laminated shingles, there is also usually a clearly defined nail line/location. Starter strip shingles, however, do not typically have a well-defined nail location. Although the nails cannot merely be placed randomly, their location on the shingle is less critical than it is for the shingles in the field of the roof. For IKO’s Leading Edge Plus starter shingles, the application instructions call for four nails, one at each end, about an inch from the end of the shingle, and two more spaced equally along the shingle’s length. To ensure the nails don’t risk being exposed or interfere with the shingle sealant system, they should be located about 3 to 4 inches from the exterior edge of the shingle.

diagram showing where to place nails on asphalt shingles

diagram showing a perfectly nailed nail on aspahlt shingle

Isn’t it just an upside-down shingle?

One of your friends, who perhaps helped shingle his uncle’s cottage once, may have told you that the starter shingle is simply a three-tab shingle installed “upside down,” with the tabs facing up the roof. Well, there’s another thing your friend misinformed you about.

Diagram showing three tab shingle sealant line

In the day when three-tab shingles dominated the asphalt roofing market, this orientation of using three tabs as starters was occasionally used. And while this shortcut did protect the roof deck at shingle joints and cutouts, it unfortunately left that first course of shingles unsealed and vulnerable to wind uplift. The sealant on an upside-down three-tab shingle ends up far too high up the roof to effectively seal the first course of the finished shingles. The proper way to adapt three tabs as starters is to trim the tabs off the shingle along a line across the tops of the cutouts. This yields a strip with the sealant at the bottom — the location where it can be useful (read on to find out how). This labor-intensive trimming step is eliminated with the use of modern, premanufactured starter shingles, such as IKO’s Leading Edge Plus.


Do they have sealant?

starter shingle - half trimmed down the middle

Yes, they do. As discussed above, a critical requirement for starter shingles is that they DO have sealant, down at the shingle’s lower edge (or outer edge at the rake). At this location, the sealant is very useful: At the eave, it seals the bottom edge of the first course of shingles, and, at the rake, it helps seal the shingle ends in each course, mitigating wind uplift. Leading Edge Plus starter shingles have a strip of IKO’s aggressive Fastlock sealant on each shingle piece to help overall roof system performance.


Length and coverage considerations.

When you buy a bundle of shingles for your roof, typically you look at the coverage as a function of area (for example, three bundles might cover 100 square feet). Starter shingles are not sold by area covered. Rather, the useful dimension here is a linear measurement, i.e., how many linear feet (or meters) can you get from one bundle. When you measure your roof, you’ll need to know the total length of all the eave and rake edges. Compare that number to the linear coverage of the starter strip you plan to use, and you can determine how many bundles of starters you’ll need to get. IKO’s Leading Edge Plus is efficiently designed and packaged in such a way that each shingle separates lengthwise into two starter strips. So, a bundle of 18 shingles yields a generous 123 linear feet of coverage per bundle (118.1 linear feet for product available in the Northwest).

bundle of IKO's Leading Edge Plus starter shingles

Regarding length considerations, it is important that the joints of the starter strip shingle are not coincidental with the joints in the overlying finished roof shingles. If the starter shingles and the finished shingles are the same length, and you correctly begin laying the starters at the eave with about 20 inches removed from the first strip, then joints in both courses will never align. However, if the length dimension of the finished shingle is different from the starter, they may eventually align, depending on how long the eave is. In this case, just monitor the situation, and, if necessary, at a certain point along the eave edge, trim a portion off a starter and continue.


Special situations.

In most cases, a single layer of starter strip is all that’s needed to cover the perimeter of your roof. However, there is at least one special case where two layers of starters are needed at the eave.

Armoushake starter shingle diagram

Normally, the finished shingles cover the starters entirely, so, as mentioned above, the color of starters is completely irrelevant. However, certain shingle designs, such as IKO’s Armourshake, have intermittent lower exposed tabs. When those shingles are installed at the eave on the first course, the starter is visible, and, therefore, its color is relevant. In this case, an additional starter shingle course, in matching colors to the finished shingle, is required as a secondary starter layer. As it turns out, this second starter layer also satisfies another aspect of these specialty shingles, in that the entire roof area is now appropriately covered in two shingle layers, including the intermittent tooth area at the eave.

Starter strips are an important and integral part of an asphalt shingle roof system. They aid the roof’s water-shedding function by covering shingle joints (and cutouts in traditional three-tab shingles) at the eaves. They greatly improve the roof’s wind resistance by sealing the finished shingles to the roof at eaves and rakes. Whether you use ready-to-use starters, like Leading Edge Plus, or cut starters manually from three-tab shingles, ensure they are installed along all roof edges.

To learn more about starter strip shingles, or to have them installed on your roof, please visit our Contractor Locator to find a local roofer in your area.

Watch the video below to learn more on how IKO’s EdgeSeal helps reduce shingle blow-offs

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