How to Install Roll Roofing for Low Sloped Roofs

architecture symmetry with straight lines of house roof gables with chimney

Flat or low-sloping roofs need to be maintained in good condition, even more than hipped roofs. This is because the water spends more time on the roof, and can even pool in places that sag. For this reason, it’s smart to know how to install roll roofing on a roof.

Roll roofing is made of asphalt with a similar weight as asphalt shingles. However, it is easier to install. It can be used as a primary roof or as flashing on pitched roofs. There are various degrees of weight. While the standard color is black, there are alternative hues as well. Here is an explanation of how to install roll roofing on flat or low-sloped roofs.


The first item to consider is the service durability you expect from your roof. If you want a life-long good, you should increase the roof material weight or thickness. Keep in mind, the thicker the material, the heavier the roof will be. Moreover, you will have a harder time with installation. If you plan to purchase the materials in advance of installation, make sure you store them in a warm environment.

You need to consider the structure you are installing the roof on and how the weight bearing specifications will hold extra weight. One important benefit of roll roofing is that it is always lighter than individual asphalt shingles. If the roof can handle the weight of shingles, you can use a maximum thickness for your rolled roof.

Roof Preparation

worker's tool belt left on roof with half shingles half without

When applying a rolled roof material over an existing shingle roof, you need to remove all the shingles plus the nails from the old construction. Nails have a tendency to create bubbles in rolled roofing. The importance of preparing the sub-roof in how to install roll roofing is critical to a good finished product.

Peel away all roofing felt and repair any signs of damage. Inspect and replace any damaged flashing. Flash around all roof vents and any other openings. As part of the preparation for how to install roll roofing, decide on the preferred direction of installation.

Long roofs should run parallel to the eaves. Meanwhile, short roofs offer you the option of going either direction. Decide if you want to use an adhesive or nails to secure your roof. Usually, professional will recommend you to follow the no-nail method.

Using a rolled roof adhesive instead of nails adds to durability and helps to avoid leaks. Rolled roofing does have excellent durability. On the other hand, using adhesive plays well as a preventive plan when you may need to replace the old material.


To understand how to install roll roofing, you should realize that much of the durability comes from using proper overlap. To begin with, you should cut in the entire roof with strips that are at least 1-foot in width. You will run this edge on both sides of the roof cap, along the eaves, and up each side.

If you’re using adhesive, roll out an even strip along the outside of each edge. A small 4-inch roller is the best tool to use for this application. Nails should be used at 1-inch and 8-inches from each outside edge.

One acceptable method for how to install roll roofing is to attach all the edging strips with nails. Afterwards, apply adhesive for the remaining strips. If you are going to use nails to install the rolled roofing, you should definitely apply the concealed nail method. This simply means running each nail row no less than 3 inches under the next row, creating an overlap.

Do not forget to cut individual edging to go around vent flashing as well. If you take the time to install a good edge before running your strips, you will avoid bubbling and buckling issues when you try to cover these tight areas.

The Rows

Once you decide which direction is most suited for your roof and you have edged it out, begin to run the rows. Each row must overlap. The recommended measurement for roll roofing overlap is at least 6-inches. While there isn’t much advantage gained by overlapping more than 6-inches, this is a recommended minimum.

To help keep your rolls straight, set a chalk line for each new row. Remember to subtract 6-inches from the total width of the roll. It may seem simple enough just to roll out the material and attach it. However, the chalk line helps to keep the roll out even. Again, professional explanations for how to install roll roofing allow minimal overlap that is as thin as 2-inches. Nonetheless, this can cause problems.

When you begin to shift off-line even slightly, you’ll find that the material has the tendency to buckle or bubble. Use a wide paint roller to smooth out each row. Do not install more than one row at a time and be consistent with the amount of adhesive or the nail line. Each of these precautions will help improve the lasting durability of your finished roof.

If this happens, you essentially need to start all over. This is why paying attention to few prevention steps can help your project progress smoothly. Follow your courses, always finishing at a roof hip or ridge. This makes it easier to adjust for shorter widths on the last row.

In Conclusion

Using rolled roofing for flat or low-slope roofs is a convenient alternative to conventional shingles. There is less mess and little or no piecework. The finished product has nearly the same durability ratings as conventional asphalt shingles.

Now, when you begin to do cost estimates you immediately find out what is most appealing when comparing the two options. Using rolled roofing can save you up to 75% over conventional asphalt shingles. All you need to do is get the right weight material and follow these simple steps for how to install a roll roof. When you do, you get years of use out of your roof.

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