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The way to put in a Roof Over an Existing Roof

Installing a new roof over an existing one, also called a *layover* or *nailover*, is frequently possible but not always the best choice. A correctly installed layover roof may look and operate and one installed after ripping the present roof and is typically more convenient and less costly. Although a lot of steel roof systems could be applied over an present roof, layovers are far more commonly done using asphalt shingles. **Pick a shingle style using the exact dimensions as those on your existing roof** to offer the best appearance.

Determine the Feasibility

Multiple layers of shingles may make it hard or impossible for the nails to penetrate the decking adequately, causing shingles to ignore or don’t seal properly. The additional burden of multiple layers may also be more than the roof facilitates could bear. Inspect your attic to get cracked or sagging rafters — a sign that a layover can cause much more damage. If you currently have multiple layers of shingles or signs of damage to your roof supports, you must prevent a layover. Some producers will not cover product failure if their shingles have been installed as a layover and some municipalities limit the amount of layers you may have.

Inspect the state of Your present Roof

The state of the existing roof is critical. The roof should be in sound condition without any unrepaired leaks. • Stand at street level and look for any dips or sags from the roof. This can indicate issues with the wooden deck or rafters supporting it. • Walk around the roof to find out if there are any places that feel soft or mushy. Soft spots are signs your decking needs to be mended or replaced. Whether there are a lot of soft spots, it is typically best to prevent a layover. • Look for shingles that have curled or cupped. You can trim or remove those shingles prior to applying a layover, however, your new roof will not be as even-looking and might have difficulties sealing properly.

Install Drip Edge

Drip border, or border steel, is a piece of steel that goes approximately 0.75 inch past the roof’s edge to channel runoff into your gutters. To install it, slide the flat, broad flange under the first row of shingles as much as it will go. Check to see that the bottom border is positioned over the gutter; if not, adjust the flange under the shingles until the drip edge is correctly positioned. Use a felt-tip marker to make a short line on the drip edge to signal appropriate position. Eliminate the drip edge and apply a thin strip of roofing cement at the very top border over the line you indicated and slide the drip edge back under the shingles into the mark you made. You may also use roofing nails to secure the roof edge.

Install Starter Strips

The first row of shingles is called a starter strip. You can either purchase starter strips or create your own by cutting shingles to dimension. To create your own, use the apartment, solid part of the shingles and a heavy duty knife knife to cut pieces that are around 5 inches wide. Place the top of each starter shingle firmly against the base of the shingle immediately over it and even with the eaves, then nail it into position. Use 1.5- or 1.75-inch roofing nails. Your second row of shingles must be cut to 10 inches wide. Butt these against the base of the old roof’s third row and nail into position.

Flashing and Additional Rows of Shingles

Flashing must be installed properly around elements, like vents or chimneys, that penetrate the roof, in addition to in valleys where different areas of the roof match. When doing a layover, the depth of the layers may make it hard to utilize any method aside from steel valley flashing. To install, line the valley with underlayment secured using roofing cement. Cut the flashing into 6- to 8-foot lengths to help prevent buckling following setup. Apply roofing cement into the rear of the flashing, then nail it into position, keeping all nails a minimum of 6 inches in the flashing’s centerline. The borders of the valley flashing should be under the new shingles. Continue installing the remaining shingles by butting each new row snugly against the base of the present row of shingles immediately above and nailing into position.

Finishing the work

Depending on the kind of shingles you’ve chosen, you might want to use a special sort of shingling substance, called *hip and ridge*, to cover the summit where your roof planes meet. If you are using three-tab shingles, however, you may cut shingles to produce your own. Use a heavy-duty knife knife to separate the shingles into thirds by cutting them at each tab. Mark the middle of each section and use a compass to mark 30-degree angles along the sides of each section from the end to the middle line. Cut along these marks to make a piece that looks like a trapezoid topping a rectangle. Folding each piece over the ridge and nail it into position. Nails must be set in the trapezoidal region formed by cutting the angles. Overlap each piece so the section without angles covers the trapezoidal location.

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