A shed’s roof typically lasts a quarter-century. Sometimes due to weather conditions and other factors, the roof can start to show signs of wear and tear before their predicted lifespan is over. If your shed’s roof is starting to show signs of wear, you may be considering your options, and perhaps have come across the idea of putting a new metal roof over your existing shingle roof.
But can you put a metal roof over your existing shingle roof? By the end of this blog post, you’ll learn if it’s a good idea to install a metal roof over your existing asphalt roof and some warnings about doing so.
Factors To Consider When Installing A Metal Roof Over Shingles
- Before you install a metal roof over your existing asphalt roof it’s important to check with your local zoning and building departments to make sure they approve of metal over shingle installations.
- It’s important to check your shingled roof for leaks, if there are any signs of breakage and leakage you need to fix them before installing the new roof.
- If there is any damage caused by the weight of the current roof such as buckled trusses or sagging in the decking. You need to fix these issues before the new installation begins.
- It’s usually a good idea to consider adding some type of underlayment on top of the shingles to prevent their granules from contacting the metal and leading to corrosion. Your shed contractor can tell you more about the options you have.
Hence before installing a roof over your existing roof you need to keep the aforementioned factors in mind.
Limitations Of Installing A Metal Roof Over Shingles
Installing a metal roof over your existing asphalt shingles comes with its limitations. Here are the drawbacks of installing a metal roof over shingles.
- Your decking will be covered up by your old asphalt shingles. Deckings are the wooden frame that makes the framing of your shed’s roof. Your roof and other components are installed on these boards. If you install a metal roof on your existing roof the roof contactor won’t be able to check your decking for damage leading to costly problems down the road.
- When you install a roof over your existing roof it becomes harder to track future roof leaks. So, when your leaky asphalt roof is covered by the metal roof, it becomes harder to fix the roof afterwards. Hence it is important that before you install a metal roof over your existing roof, you hire a professional to check for any leaks or structural damages. These issues can pose serious damage in the long run.
- When you fully replace a roof you replace all its components. But when you install a metal roof over your existing asphalt roof, you miss out on replacing crucial components that are included in a full roof replacement. This might save you money initially but could lead to some costly repairs in the future.
Can You Install A Metal Roof Over Shingles?
This depends on the condition of your shed’s roof, you need to check what the condition of your existing roof is. Your current asphalt roof has to be near the end of its lifespan and should be lying down pretty flat (no lifted or cracked shingles, blisters, or bumps). With that in mind, most roofs won’t be good candidates because of the wear and tear they go through during their lifespan.
You also have to check how many layers to your roof there are. If you already have two roof layers then you cannot put a metal roof over them. But if you have a single asphalt roof then a metal roof can be put over it.
So, if your existing shed’s roof is laying pretty flat and there is just one layer to the roof then you can install a metal roof over it. As long as the metal roof is installed properly by professionals it can be done without a problem. Since you won’t be tearing the existing roof you will be able to save a lot of money on labor cost.
About Stahl Storage
Stahl Storage offers the most reliable, durable, and easy to maintain storage sheds and garages in Alberta. These premium storage options include modular buildings, cabins, storage sheds, garden sheds, portable workshops, offices, and more. For more information, visit our website.