Whether you recently built a deck, or wish to upgrade the existing one, adding a roof over the deck can be a great addition to your home. A roof over your deck protects from weather elements, like rain and snow, while adding an aesthetic touch to make your outdoor space more inviting.

The best part is that you don’t have to break the bank to install a roof over your deck. And if you do it right, a patio roof can significantly boost your property value so that you will reap most, if not all, of your investment back.

In order to build a roof over a deck, you will need to connect the new roof framing to the existing building. The most effective way to do this is to use post and beam construction and have the rafters connecting the beam to the building.

Other, more involved methods require you to remove a section of the existing roof, add in new trusses, and other framing options for the new roof that will go over the deck.

Read on to learn more about how to build a roof over a deck.

Types of Roofs Over Deck

Before you decide on building a roof over your deck, you should consider the different types of roofs that are available. The three main patio roofs for decks are gable roofs, hip roofs, and slanted roofs.

Gable Roof

A gable roof is the most popular type of deck roof and consists of two equally-sized slanted sides with a horizontal ridge at the top. This design allows water to run off quickly from the sides and provides good ventilation throughout the entire structure.

Building a Gable Roof Over Deck

A gable-style patio is also ideal if you wish to attach solar panels or any other feature above your deck since it has adequate space for mounting such items.

Some aspects to consider before you install a gable roof over your deck include cost, materials, and weather in your area. In addition, the installation of a gable-style roof will depend largely on the size of the deck and how you wish to customize it concerning features like insulation, skylight windows, or any other specialized features.

For example, a gable roof may require additional or expensive materials compared to a shed roof since it will need more support from the walls and other features.

Hip Roof

A hip roof is similar to a gable-style roof in that it has four slopes of equal size. The main difference between these two types of roofs is that while the gable style has two sloped sides and one horizontal ridge, a hip roof consists of four ridges that connect at the top.

One advantage of this type of patio roof is that it is more stable than a gable-style roof due to its design. This makes it ideal for high winds or heavy rain/snowfall areas. Additionally, consider this type of roof if you want a modern look and more style options.

Hip roofs can be installed in two ways – cut hip or half hip. A cut hip is used when the deck has four sides, while a half-hip is used when it has three sides. Just like with gable roofs, the materials required for installing a hip roof will vary depending on your needs and preference.

Slanted Roof

As the name suggests, a slanted roof has two sides sloped inwards. This type of roof is also known as a shed or lean-to roof and provides adequate protection from the elements. A slanted roof may not withstand heavy winds or snowfall, but it can provide enough shelter from light rain and sun rays.

One advantage of this type of roof is that it is cheaper and easier to install than other types. Also, you have more options concerning materials for constructing a slanted patio roof since there are many variations available on the market today.

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Best Materials for a Deck Roof

A deck is a huge investment, so you want to use materials that will last. Here are some common and easily accessible materials for your deck roof.

Asphalt Shingles

Asphalt shingles are the way to go if you want a seamless look. These are lightweight and come in various colors and textures, so you can easily find one that complements your deck and home décor. Asphalt shingles also provide good wind resistance, which is essential for any roof.

But before you settle for asphalt shingles, consider their life span. Shingles tend to last only 15-20 years, so if you want a long-term solution, there may be better choices than this. In the same way, consider other aspects, like how your roof can handle heavy snow or rain.

For instance, if you live in an area that experiences heavy snowfall, then there may be better options than asphalt shingles since they can easily crack or break when exposed to extreme temperatures.

Metal Panels

Metal panels are the way to go if you want a roof that can withstand harsh weather conditions. They are available in various styles and finishes, so you’re sure to find one that complements the look of your home. In addition, metal roofs are durable and energy efficient, which adds to cost savings.

Installing Metal Roof Panels Over Deck

The other main perk of metal panels is that they are much lighter than other materials. This means you won’t have to worry about additional weight being added to your deck, which is especially beneficial if it is situated on an upper level of your home.

Polycarbonate Roof

This roofing material is lightweight yet durable and resistant to most weather conditions. Polycarbonate roofing material is also available in various textures and colors, so you can easily find one that suits your style preferences.

What makes this type of roof great for decks is its insulating properties. It helps keep the area underneath warm during the cold winter months. Additionally, polycarbonate roofs are designed to be shatterproof, meaning they won’t crack or break from exposure to heavy winds or snowfall.

Polycarbonate roofs don’t bend even in cold temperatures, so they remain effective in all kinds of weather. Furthermore, they are relatively easy to install and can last up to 25 years with proper maintenance.

The only drawback of polycarbonate roofs is that they are relatively expensive compared to other roofing materials. However, given their long lifespan and durability, the cost is often worth it.

The Cost of Building a Roof Over a Deck

Generally, the cost to build a roof over a deck can range from $3000 to $10000, depending on labor and material costs. But this cost differs based on a range of factors, as follows.

Size of the Deck

The size of your deck will be a big factor in determining the cost of building a roof over it. Larger decks require more materials and labor, so they are generally more expensive than smaller decks.

Type of Roofing Material

Asphalt shingles are relatively cheaper compared to metal panels or polycarbonate roofs. However, remember that these roofs may only last for a short time due to their limited lifespan. So consider the upfront cost when deciding on a roofing material.


It’s important to remember that labor costs vary from place to place. If your deck is situated in an area with higher labor costs, this could add additional cost to your project. Take your time to research the labor costs in your area before settling on a contractor.


The design of your roof will also affect the overall cost. This is because certain designs may warrant more materials or labor than others. So when selecting a design for your roof, it’s important to keep this in mind.

DIY or Professional Installation

You can save money by opting for DIY installation. However, keep in mind that this requires a lot of time and effort on your part. Suppose you aren’t confident in your ability to install the roof properly. In that case, hiring a professional who can do the job quickly and efficiently without compromising quality is best.

8 Steps to Building a Slanted Roof Over an Existing Deck

Now that you understand the basics of building a roof over a deck roof, here are easy-to-follow steps to building a slanted deck roof.

1. Form Your Plan

Every project requires a plan, and this one is no different. Before beginning your project, take a moment to consider the design of your roof and make a list of all the materials you will need. Some essential aspects to include in your plan are:

  • The size of the deck and roof
  • The type of roofing material you will use
  • How you intend to support the roof’s weight
  • How many trusses are needed in the roof build
Plan To Build Roof Over Deck

Besides guiding you through your project, a plan is handy when applying for a permit to build a roof over an existing deck. Therefore, always include a plan when applying for permits.

2. Prepare Your Home for Framing of New Roof

Once you have your plan in place, it’s time to prepare your home for framing. First, you want to ensure your existing deck is level, clean, and debris-free. The roof should also connect seamlessly with the existing walls, so leave enough room for framing.

First, measure the height of the deck. Then mark out where you want to install your roof trusses using string and a marker. You should then install blocking between the existing walls for support.

Prepping also involves installing a nailer around the edge of your deck. This will provide a place to attach the roof trusses and other metal components.

3. Install Connectors for Post Base

You shouldn’t just rely on the existing posts for support, as they may not be able to handle the weight of a roof. Instead, you can install post bases to support your roof.

Before attaching them to your deck’s posts, you must secure the post base into concrete. This step ensures that they are firmly in place and ready to take on the weight of your roof.

You may dig up your deck’s posts to access the concrete before installing the post base. Or, you may leverage existing concrete for the post bases.

Whichever the option, the goal is to create a stable base for your roof. So, take your time to inspect the post base and ensure it is properly secured. And if necessary, use strapping for additional support.

4. Install the Posts

The posts are probably the most important element of your roof build, as they will carry the most weight. Measure and cut your posts to size for a seamless installation.

Then, attach the posts to each post base using screws or nails. Again, ensure that you’re installing them securely into place so they can carry the weight without any issues.

Once all your posts are in place and secure, use a leveler to check whether they are exactly aligned with each other across the deck area.

The ideal post size should be 6-by-6 inches, but this may differ depending on your project. For example, suppose your slanted roof is covering a larger area. In that case, you may require bigger posts for added support and stability.

5. Install the Beam

At this point, you will need to install the beam. The beams are essentially the inner frame of your roof and provide additional support for the entire build.

You may need a beam table to guide you with the installation. And you can use your plan to determine where each beam should be placed.

Make sure that each beam is securely fastened and connected with all posts, joists, and trusses. Also, inspect the table for any weak points or defects before moving on to the next step.

6. Install the Rafters

Now that the main structure of your roof is in place and stable, it’s time to install the rafters. These support the entire roof build and give your roof an aesthetic finish.

Start by measuring and cutting each rafter according to size before nailing them into place along the trusses and joists. You may need a hand saw, gloves for this step, and safety eyewear due to potential debris.

Once all your rafters are set in place, use a leveler to check whether they are level with each other across the deck area. You can adjust them accordingly until they are evened out if they aren’t. Finally, use a hammer and nails to fasten the rafters into place.

7. Install Roof Sheathing

Roof sheathing offers limitless benefits when building a deck roof. First, it provides extra protection against wind and rain. Also, sheathing allows your roof to be stronger and sturdier.

Start by measuring the length of each sheet of sheathing before cutting them to size according to your plan. Then, use a framing nailer or hammer and nails to securely attach the sheets along the rafters on each side of the roof.

You may need additional material, for added strength. But, again, consult with a professional contractor if you are unsure which type of material is best for your project.

Once all your sheathing is in place, add any additional materials necessary for reinforcement where needed. Depending on your design plan, the material could include adding shingles or other protective coatings over the entire deck area.

Additional Reading: Complete Guide To The Types Of Wood For Construction

8. Install Roof Material

The type of roof material you install on your deck depends on your design plan, budget, and preference. For added aesthetic value, you could choose from various materials such as asphalt shingles, metal panels, tiles, or even wood boards.

Installing Roof Shingles

Start by measuring the length of each material before cutting them to size according to your plan. Then, use a hammer and nails to attach the roof materials over the sheathing securely. Make sure that all nails are hammered down into place for extra stability.

Finally, inspect the entire area for any defects or weak points before moving on to the next step. At this point, you can start to finish up your deck roof build. This could include adding additional protective coating or materials such as insulation and siding. Also, if you need additional components, such as vents or skylights, this is the time to install them.

Also, remember to inspect the entire build before officially declaring it complete. Make sure that all posts, joists, trusses, rafters, and sheathing are securely fastened and placed with nails or screws. Otherwise, you risk having a weak foundation which may compromise the entire structure of your deck roof build in the future.

Key Differences When Building a Gable Roof

Building a gable roof over your deck is slightly more complex than building a slanted roof. First, you will need to install an additional truss along the peak of your roof. This step allows the two sides of your roof to meet in the middle and form an A-frame shape.

Also, you may need additional support beams or joists for added stability if you are dealing with heavier materials such as tiles or metal panels. Finally, most gable roofs require extra protective coating due to their steep angle and large surface area. This could include adding sealants and reinforcing materials such as insulation or siding where necessary.

In summary, when building a gable roof, there are several key differences compared to building a simple slanted roof. These include installing an additional truss along the peak of your roof, adding extra support beams or joists for added stability and protection, and using heavier materials such as tiles or metal panels.

Frequently Asked Questions

Here are some commonly asked questions about building a roof over a deck.

  • Do I need a permit to add a roof to an existing deck?

    Yes, you need a permit before undertaking a deck roof project. The main aim of the permit is to ensure you meet all safety standards. Otherwise, you risk having a structure that may compromise the safety of your family and visitors.

  • Does a deck roof add value to a house?

    A deck roof to an existing house can add value to your home. But a range of aspects determines how much value you can get from this investment.

    For instance, the quality of the materials and workmanship used, as well as the design of the roof. In addition, the roof should be functional and aesthetic, so it needs to be well thought out and constructed properly.

    Your region determines how much value you can get from a deck roof. For example, if you live in an area with a cold climate, installing a roof can help keep your home warm during winter. Potential buyers may be more attracted to your home due to the improved insulation properties.

  • Why build a roof over a deck?

    Building a roof over an existing deck offers limitless benefits as follows.

    Protection from elements

    The major benefit of building a roof over a deck is its protection against poor weather conditions such as rain, snow, and wind. This helps extend your deck’s lifespan and ensure its durability for longer.

    Enjoy anytime

    A roof over your deck allows you to enjoy it regardless of the weather. You can have barbecues and parties or relax on your deck without worrying about rain and snow.

    Space for dry outdoor projects

    A deck roof also allows you to undertake outdoor projects such as painting or installing a swing without the fear of getting wet.

    Provide shade for certain plants

    The roof covering also provides shade for plants that grow on your deck. This benefit protects delicate plants from extreme weather conditions and potentially adds years of life to them.

  • What is the best option for roof decking?

    The best option for roof decking depends on several factors, such as cost, weather conditions, and usage. For instance, slanted roofs are more affordable and easier to install than gable roofs. But they aren’t ideal for areas with heavy snowfall or rainfall, as the water may collect on the flat surface.

    Gable roofs have an A-frame shape, making them better for dealing with rain and snow. They offer superior protection against elements of nature but require additional support beams or joists, which increase their cost.

    Therefore, it’s important to consider your local weather conditions when deciding the best option for deck roofing. It’s also essential to use quality materials for maximum durability and efficiency. This will help you get value from your investment in the long run.

Final Thoughts

Now that you know how to build a roof over a deck,  you shouldn’t have any issues keeping your BBQ dry and your guests cool. It increases the value of your home, protects you from the elements, and enables you to enjoy your outdoor space anytime. 

However, it is important to use quality materials and think carefully about the design before starting the project. This will help ensure maximum durability and efficiency from your roof decking investment.