In Arizona, summertime high temperatures routinely soar past 100 degrees Fahrenheit. The long, hot summers and cold winter nights can wreak havoc on asphalt roofing shingles. When you know it’s time for a new roof, you might wonder if you can just install new shingles on top of the old ones. Let’s take a look at whether or not it’s possible, and if so, if it’s a good idea.
Can New Shingles Be Put Over Old Ones?
In short, the answer is yes. New shingles can be installed on top of old shingles. Some Arizona homeowners choose this option in order to save money. When you have the roofers install a layer of new shingles over the old ones, you save on the labor cost of removing the old shingles and the disposal fee for the debris. You also won’t have to pay for other roofing materials, such as felt paper or reflective membranes.
Neighbors and passersby won’t notice that you installed a layer of new shingles on top of the old ones. When it’s done right, your roof will look just as good as it would if the old shingles were torn off. The new shingles will last as long as they would if you had a complete re-roof.
A second layer of shingles might also offer more protection for your home. In the event of a monsoon or other storm, you won’t have to worry about water entering your home due to missing shingles. As long as the new shingles are installed by a certified team, manufacturers offer the same warranty as they do for a re-roof.
When to Tear Off the Old Shingles
While there are many advantages of having roofers install new shingles on top of the old ones, sometimes it’s not a good idea to do this. In some cases, building code even prohibits the installation of another layer of shingles. If your home already has two layers of shingles, you can’t add more. Roofers must comply with building codes and will not install a third layer of shingles.
- You shouldn’t add another layer of shingles if the current layer is in bad shape. Curling, cracked or pitted shingles will cause issues with the new shingles. If the shingles have any warping or holes, they must be removed and replaced. Click here for more info on how to tell if you need to replace your shingles.
- If your roof already leaks when it rains, it’s better to tear it off and start fresh. Simply adding more shingles won’t stop the leak. Leaky roofs may also need new plywood, flashing or other materials in order to fix the leak.
- Roofs that are soft or spongy need a full replacement. The sheathing or joists may have structural issues. Soggy sheathing or rotted joists may not be able to support two layers of shingles, so a roof replacement is better in this situation.
- Two layers of shingles may trap more heat in your home’s attic. If your home already gets too hot, this may result in unbearable discomfort. The added heat could also place a burden on your air conditioner and cause it to cycle more frequently. These additional cooling cycles will run up your electricity bill and may cause premature failure of your home’s cooling system.
- Not all homes were designed for the roof to support two layers of shingles. Although one shingle doesn’t weigh much, a typical 2,000 square foot, single-story home has thousands of shingles. Altogether, these shingles weigh around 5,000 pounds. If the structure of your roof can’t support two and one-half tons of additional weight, the old shingles must be torn off. Rely on a roofing expert to determine whether or not your roof’s structure can support the weight of two layers of shingles.
Turn to Our Professionals
The trusted Phoenix roofing contractors at JBS Roofing provide expert insight about whether you should do a complete re-roof or if it’s okay to add a new layer of shingles on top of the old ones. We offer free inspections and honest assessments of your roof’s condition. We’ll explain our findings and answer any questions you have about your options. For more information or to schedule an inspection of your home’s roof, reach out to us today!