Pros and Cons of More Than One Layer of Shingles

Pros and Cons of More Than One Layer of Shingles from Republic Roofing. Roofing deteriorates just like any other part of your home over time. If your roof is damaged in a way that cannot be repaired, it is best to have it replaced. It’s easier said than done, but replacing a roof requires a significant investment of time, money, and effort on your part to ensure that your roof is in good working order once the job is complete.


The process of replacing your roof can also be messy, take a week, and cost you a lot of money, all at the same time. You’ll also need to hire a crew of roofers to install the new shingles because you’re effectively tearing down your roof and replacing your older layer of materials. If you’re spending money on your roof, why not make sure it’s installed correctly?

There are, however, some homeowners who prefer to keep their old shingles in place and simply install a new layer on top of them. Although most roofing contractors do not recommend it, it is still possible. There should be how many layers of roofing on top of each other your roof may not be able to withstand it. These questions will be on the agenda.

How Many Should There Be?

Simply stated, your roof should only have two layers of roofing materials. Most roofing materials are heavy and can weigh more than a tone, so homeowners need to keep this in mind. Before putting slate tile roofing on top of other materials, you must make sure that your home’s supporting structure can handle the weight of the roof.

For most roofs, the average area is around 1700 square feet and the materials are sufficient, so it’s a good idea to figure out the weight. In addition, use the following questions as a guide:

  • Do I need to upgrade my roof’s support?
  • Are there still damages to my older layer? Should I patch them up? 
  • Are there any organic and fungal growths on the older layer? 
  • Are the new set of materials compatible with the older layer? 

Once you have checked and inspected the older layer of materials and found no damages, you can start laying your new set of shingles. This checklist will help mitigate any future damages that might happen because of overlaying. 

Why You Shouldn’t Overlay

Because of these reasons, it is not recommended to put roofing materials on top of one another.

Voids Warranties

In the case of roof repairs and maintenance, warranties are your best friend. You don’t want your warranty to be voided at any point. For warranties to be valid, homeowners must adhere to a set of rules. Having a valid warranty can save thousands of dollars in labour costs and replacements that would otherwise be spent.

Makes Reports Look Bad

Overlapping is not the best option if you plan on selling your house and making the necessary improvements and renovations to your roof before you do so? 

This could result in your home’s value being reduced if a home inspector finds that multiple shingles are stacked on top of each other during an inspection of your roof. This is a red flag that should be noted in the report.

Cuts Your Roof’s Lifespan

Finally, the process of overlaying your roof can result in a wide range of issues. Before placing your new layer, make sure that your old layer’s issues have been resolved. This can affect your new layer as well. Your older layer’s rotting mildew and mosses can spread to your new layer and erode the foundations of your newer layer, causing it to fall apart.

To cut to the chase, only two layers of roofing material should be used on top of each other. To save time and money, you might opt for a quick replacement, but in the long run, this will only lead to more problems. The best way to ensure that your roof is in perfect condition is to hire a professional and qualified roofing contractor to inspect it.

When it comes to making sure that your roof is in good condition, tearing down the old shingles on your roofing in TN, is the best course of action. It’s understandable that you wouldn’t want to throw away all your efforts.

 Call Republic Exteriors today in Collierville, Bartlett, Germantown, and Lakeland, TN at 901-437-5278.