The gutters should extend beyond the roof tiles, not align with them. Water naturally flows through the shingles, along the edge of the shingles and even under them. When gutter sections are installed directly in line with the roof tiles, the shingles impair the natural flow of water. In most areas, gutters will be installed against the fascia, with approximately 3″ to 4″ of the width of the gutter extending beyond the edge of the shingles.
Depending on the inclination of the fascia, the gutters may need a bracket installed behind the rear wall of the gutter to be level. The trailing edge of the gutter should rest under the edge of the drip edge flashing to prevent water from entering behind the gutter. A gutter that is not properly installed will not pick up stormwater runoff from the roof as expected and could cause damage to the home. Gutters should extend beyond the roof to trap and drain water without splashing the roof or siding, especially in heavy rain.
Without this extension, water will begin to cascade down from the roof instead of dripping through the downspout and may leak the gutter. Normally, the gutter does not extend beyond the sloped edge of the roof. It is often held an inch or two behind. Because gutter installation isn't one of the most complicated construction projects, sometimes homeowners can take on the task themselves or hire someone who doesn't have the experience to install their gutters.
A good rule of thumb is to make sure that the gutters lean toward the downspouts at a quarter of an inch for every 10 feet of your gutter. The gutters should be hung where a straight edge over the roof tiles can easily extend over the front edge of the gutter (this is the proper installation location for the high point of the gutter). An openly sloped channel is a common result of DIY methods along with too many seams that could cause leaks in many places. Before starting a DIY gutter installation, consider hiring a professional to hang your new gutters properly.
The space between the gutter and the roof can vary in size because the gutters must be tilted towards the downspout to ensure proper water runoff. Any gutter material that can be purchased at a home remodeling store will not be as strong as what a professional gutter company offers. When exposed to all the water that can flow through a gutter (even worse if there is an obstruction and the gutter fills up like a bathtub), the shingles will absorb water like a straw. The shingles should also extend slightly over the inner edge of the gutter to allow water to drain into the gutter.
Let the experienced installers at All Season Gutters know the right way to install gutters. A professional gutter installation company will use a level during installation to ensure that the gutters are sloped.