However, prior to installing a deck over your patio, there are essential steps to consider, such as assessing the feasibility of project and strategizing your design effectively. This article aims to provide comprehensive guidance through the process, covering all aspects you need to consider when undertaking a project of this nature. Continue reading to discover how to build a deck over a concrete patio. 

1. No Need to Remove Existing Concrete Surface 

A primary benefit of building a deck over concrete is the ability to revitalize your outdoor space without the need for extensive demolition or removal of the existing concrete surface, which can be costly and time-consuming. Building over the current patio not only reduces waste but also has a smaller environmental impact.

2. Easy Expansion of Your Outdoor Space

Building a deck additionally brings the benefit of expanding your outdoor living area, providing more space for relaxing, entertaining, and generally enjoying the outdoors. 

When building a deck over a concrete patio, you also overcome many limitations of the flat and plain surface that concrete provides. The addition of a raised deck offers an opportunity to create different levels or zones within your outdoor space, adding both visual appeal and functionality. 

You can even incorporate unique features such as seating areas, outdoor kitchens, or a cozy fire pit. These additions create a noticeable impact, transforming your once ordinary patio into an inviting retreat.

3.  A Blank Canvas to Showcase Your Outdoor Design Preferences 

By building a deck over the concrete patio, you create a fresh canvas to express your personal style. When planning your decking project, you’ll discover a variety of decking materials, colours, and textures. 

Whether your preference is the natural look of wood, the low-maintenance advantages of composite decking, or the sleek aesthetics of PVC decking, you have the flexibility to choose a design that suits your taste and blends seamlessly with the surrounding landscape.

4. Increased Functionality

Beyond aesthetics, there are lots of practical advantages to incorporating a deck into your garden. Firstly, decking provides a comfortable and stable surface for outdoor furniture, making it easier to arrange seating areas or outdoor dining sets.

Additionally, the elevation of the deck helps to improve drainage. This prevents water from pooling on the surface of the deck and enhances the longevity of your outdoor furniture and accessories.

When building an elevated deck, you can also create a storage space by using the area under the decking. This is very practical in colder months when you want to store the furniture that’s on your deck during warmer weather.

Assessing the Feasibility of Building a Deck Over Concrete

Before you start the project of building a deck over a concrete patio, it’s important to assess the condition of the existing concrete surface to ensure its suitability. During this assessment, you’ll determine if the patio is structurally sound and capable of supporting a deck.

This assessment could also help you identify potential issues with the patio, like cracking or sinking, that need to be addressed before you begin construction of your deck.

While it’s possible to conduct an initial brief assessment yourself, it’s always advisable to consult with a professional or a reputable deck builder for a thorough evaluation of your concrete patio.

Stability

First, check the stability of the concrete patio. This can be done by walking across the surface and noting any excessive movement, shifting, or cracking. If you notice any of these stability concerns, they could indicate underlying problems that could make the patio unsuitable for a deck in its current state. If you identify any structural issues, it’s recommended to contact a professional who can assess the extent of the damage and provide solutions to ensure your concrete patio is ready for deck installation.

Levelness

The levelness of the concrete surface is another important factor. It’s crucial for the concrete patio to be completely level to ensure the stability of the deck. The levelness of the patio can be checked easily using a level or string level.

If there is sloping or unevenness, this will need to be addressed before starting deck construction. Solutions include adding thin layers of concrete to uneven areas, using leveling compounds, or incorporating adjustable deck supports.

Other Deterioration and Things to Assess

You’ll also need to look for other signs of deterioration and the overall integrity of the concrete to assess its long-term durability and resistance to moisture. Things to look for include cracks, spalling, and sinking, plus any other significant signs of wear and deterioration. 

Small cracks are generally related to normal wear and tear and can easily be filled in. However, larger and more widespread cracking may suggest underlying issues and extensive damage that could mean the patio isn’t in a good enough condition to have a deck built over it. If this is the case, contact a professional to find solutions for fixing your patio so that a deck can be installed.      Lastly, consider the age of the patio and the thickness of the concrete. Older concrete is more likely to experience damage. Even if little damage is seen now, deterioration is more likely to occur, which can affect the safety and structural integrity of the deck you’ve built over the concrete.

Thick concrete will also work best for supporting the weight of your deck. If you have a thinner concrete patio, consider adding some additional layers of concrete to increase its load-bearing capacity.

Completing Your Deck Project

If after assessing your concrete patio, you decide a deck project is suitable for your space, you’ll need to look into how to build a deck over a concrete patio. The following are the steps to keep in mind when completing your deck project. 

Planning and Design

Before you begin work on preparing your concrete surface and installing the deck, it’s important to look at planning and design.

Deck Design

In terms of design, you’ll need to decide what size deck you want, the shape, and the layout. For example, do you want an elevated deck, a ground level deck, or a deck with multiple levels?

You’ll also need to choose colours (what tone deck board do you want? Do you want a single shade, a two-tone design, or a multi-shade deck design?) and materials to use, which is discussed more below.

When deciding on design, keep functionality in mind as well. If you want a deck next to your home and your access door to the outdoor space is around ground-level, an elevated deck won’t be an option. Or, if you have a smaller outdoor space, it’s important to determine what size deck will enhance your space instead of overwhelming it. You’ll also want to ensure the deck doesn’t block any adjoining doors.

Even when choosing colours, consider your existing garden and any outdoor furniture you have. For example, if you have lots of vibrantly coloured plants, grey decking is an excellent complement to that. On the other hand, if your garden features lots of greenery, you may want to opt for more natural wood tones.

Need some ideas for your deck project? Take a look at our Get Inspired page, which features inspiration for all types of outdoor spaces and style preferences. 

Deck Planning

There are also some planning elements outside of the design of your deck to keep in mind. Before embarking on your deck project, ensure you have obtained all necessary permits for adding this addition to your backyard, and make sure your chosen design complies with all local building codes.  You can research this for yourself and obtain any necessary permits, or your deck builder should be able to help.

Preparing the Surface

The next step in building a deck over a concrete patio is preparing the surface of the patio for the deck installation. No matter what the condition of the patio, you’ll need to sweep and then clean it well before deck installation begins. You can do this with soap and water or opt for more heavy-duty cleaning products and a power washer.

Next, repair any damage to the concrete patio, such as fixing cracking or sinking and unevenness. If you don’t fix issues like these before adding the deck, your deck may face structural issues, such as low spots over the area sinking on the patio.

If significant damage has occurred, you’ll need to call a professional to ensure the problems are adequately fixed and won’t affect the structural integrity of your new deck. 

You’ll also want to ensure that the patio is completely level. If not, add a thin layer of concrete over uneven spots to level the surface out.

In addition, you may want to apply a bonding agent or primer over the concrete. This can help even out small imperfections and will help the thin layer of concrete bond to the original concrete if you’ve opted for that method of evening out the surface. 

Choosing Your Decking Materials

When building a deck over a concrete patio, you can opt for most decking materials, from traditional wood to more sleek and contemporary composite or PVC decking. While wooden decking will do the job, choosing composite or PVC when building a new deck brings many benefits.

For example, it’s less maintenance once installed, lasts 10 to 15 years longer than wood, and doesn’t need to be re-painted or re-stained. Composite and PVC decking are both as strong and durable as wood, as well.

In addition, composite and PVC decking are much less prone to issues that you’ll encounter with wood decks. These common issues that you’ll avoid by opting for composite or PVC materials include:

• Cracking or warping
• Insect damage
• Mold, rot, and mildew
• Colour fade
• Loose screws or nails
• UV ray damage

One great way to take full advantage of composite materials, especially when installing a ground-level deck over a concrete slab or a rooftop deck, is by using composite construction boards by TruNorth. These boards elevate the deck, allowing for adequate air circulation and water drainage, which prevents damaging moisture buildup under the deck boards. Made from recycled plastics, they’re not only eco-friendly, but they also won’t rot like wood.

Eco-Friendly Materials

If you’re looking for the most environmentally friendly option, composite and PVC decking come out on top again over wooden decking. Many brands use recycled materials to create their decking boards, meaning materials are re-used, and no new trees need to be cut down. For example, TruNorth Composite Decking is made with 95% recycled content, including a rice hull core.

Heat Resistant Materials

Those concerned about their deck overheating during the hotter months will also want to go for composite or PVC decking materials. Composite and PVC decking materials these days typically stay cooler than previous generations of composite decking, and they will not crack or warp due to heating from the sun. 

The level of heat protection will vary from brand to brand. For example, TruNorth Composite Decking features heat-blocking technology, and Clubhouse PVC Decking stays up to 30% cooler than competing PVC brands!

Aesthetic Elements

PVC and composite decking also come in a range of colours (so you don’t need to paint or stain the deck boards before or after installation) and often feature wood grain embossing to resemble traditional wood. 

TruNorth Composite Decking and Clubhouse PVC Decking each offer a variety of distinct colours, from neutral sandstone and various greys to more impactful and warm mahogany and walnut. 

Enhancements and Finishing Touches

Along with choosing your main decking materials when building a deck over a concrete patio, you may want to add enhancements and other finishing touches. 

These elements can include railing, stairs, lighting, or even seating areas that can be built using deck boards. Choosing which enhancements and finishing touches to add can be based on both practical and aesthetic reasons. 

For example, if you’re building a raised deck, you’ll need to add stairs and railings for functionality and safety. However, you may then add built-in seating for style reasons, such as liking the design and the way this type of seating blends with the deck.

You could also add design elements like a pergola, which helps protect the deck from UV rays or add fencing around your deck for added privacy. TruNorth’s Slide & Go Fence is an excellent option for the latter. It’s incredibly easy to install and comes in the same 12 shades as TruNorth Composite Decking, allowing you to opt for the same colour as your deck or choose a different complementary shade.

Once you’ve decided on all the design elements for your deck, you can begin the construction process or call in a professional deck builder, which is recommended. If you want to find a reputable deck builder in your area, use our convenient ‘Find a Builder’ tool. 

Maintenance and Care

Now that your deck is installed over your concrete patio, you can sit back and enjoy it! However, you will want to keep a few care and maintenance tips in mind to keep your deck in good shape and increase its longevity.

1. Sweep Frequently

Whether you opt for wooden, composite, or PVC decking, sweeping the deck surface regularly is crucial. Removing debris helps avoid issues like mold or mildew growth.

Luckily, if you choose a composite or PVC deck, the chance of these issues occurring is very low. Therefore, while you should sweep regularly, leaving some debris now and then won’t cause major issues.

2. Wash the Deck

Occasionally, you should wash down the decking as well. With PVC or composite decking, you can simply use warm water and soap. This can be done once every few months and when spills or stains occur.

As with mold and mildew, stains and spills are going to cause little to no long-term damage to PVC or composite decking; however, cleaning them as they occur is highly recommended.

3. Protect the Deck from UV Rays

To keep the colouring of your deck in the best condition, take action to prevent UV damage. Ways to do this include using sun umbrellas or adding a pergola over the deck. Also, consider moving your outdoor furniture around once in a while to avoid differences in colour due to some areas getting more sun than others.

Conveniently, composite and PVC decking are very resistant to damage from UV rays, so you won’t need to worry about protecting the deck that much. Both TruNorth Composite Decking and Clubhouse PVC Decking feature heat-blocking technology to lessen issues from the sun’s rays even more.

4. Check for Damage Periodically

Lastly, do periodic inspections of the deck to check for damage, like signs of mold, spilling or staining, insect infestation, and the like.
Again, you’ll want to check wood decks much more frequently than composite or PVC decks as they are much more prone to damage and other issues. You should also look out for structural issues, cracking or warping, and loose screws or nails if using wooden decking.  

To learn more about how to care for your deck and make it “summer ready,” read our article on summer deck cleaning tips. If you have a TruNorth or Clubhouse deck or are considering one, also take a look at our care and maintenance guide to discover how easy it is to care for your composite or PVC deck.  

In Conclusion

As this article should have highlighted, building a deck over a concrete patio has many advantages and is an ideal way to update your outdoor space and improve functionality. However, when planning this type of project, there are also things to keep in mind. These include assessing the suitability of your concrete patio for a deck, obtaining all necessary planning permissions, and deciding on a design that suits your preferences and is functional for your outdoor space.

If you do decide to add a deck over your concrete patio, the article should also have showcased the many benefits of opting for composite or PVC decking over wood. These materials are longer lasting and more durable, significantly less prone to damage, and are much easier to maintain.

To learn more about the benefits of these materials and why TruNorth or Clubhouse decking are excellent choices, explore our in-depth resources page. You can also order samples, find out where to buy, and much more on our website. 

In this article, we will cover the benefits of building your deck around trees and offer essential tips and steps to guide you through the process.

Why Build a Deck Around Trees?

1. Enhanced Aesthetics

Building a deck around a natural element in your yard, like a tree, can create a visually stunning and unique outdoor space. It allows you to incorporate the natural beauty and shade provided by the tree, resulting in a harmonious blend of artificial structures and nature. 

As most trees and plants will have colourful leaves, for at least part of the year, this design will also add a pop of colour to your overall deck space.

A deck built around a tree is not only a distinctive design element but it also becomes a focal point in your outdoor space. It can add individuality to your deck and enhance the overall aesthetics of your property.

2. Increased Shade and Comfort

The presence of a large tree within the deck area provides natural shade, making the space more comfortable during hot summer days. This added shade allows you to enjoy your deck even in intense sunlight. The shade also protects your deck from UV rays, which can be damaging, even for composite and PVC decks.

3. Environmental Benefits

Trees offer a range of environmental benefits, including air purification, reducing soil erosion, and providing a habitat for wildlife. By building a deck around a tree, you are actively preserving and appreciating these natural benefits, contributing to a healthier ecosystem.

4. Privacy and Sound Barrier

Depending on the location and size of the tree, building a deck around it can offer increased privacy, shielding your deck from neighboring views. The tree can also act as a natural sound barrier to reduce overall noise levels.

5. Improved Emotional Well-Being

Being in nature and surrounded by trees has been shown to have positive effects on mental health and well-being. Building a deck around a tree provides a space where you can relax, unwind, and reap the emotional benefits of being in a natural environment.

What to Consider if You Want to Build a Deck Around a Tree

1. Assess the Tree’s Health and Structural Stability

Before beginning any construction, assessing the tree’s health and structural stability is crucial. Consult with an arborist to evaluate the tree’s condition, check for any signs of disease, and determine if it can withstand the construction process.

2. Selecting the Right Deck Design

Once you’ve determined the tree is healthy and stable enough to build around, you need to choose a deck design that allows for the tree’s growth and movement while maintaining a stable structure.

The deck should be flexible to accommodate the natural growth of the tree while preventing any damage to the deck or the tree’s roots.

When planning a design, you need to consider the tree’s mature size and growth patterns. Choose a design that allows the tree to continue growing in full without obstruction or damage to the deck structure.

A great way to achieve this is by opting for a design that incorporates flexible components. These can include gaps or spacing between deck boards to accommodate the natural movement of the tree.

3. Determining the Size and Location of Your Deck

Begin by carefully measuring the tree’s trunk diameter. Use these measurements to help determine the size and shape of the deck. Remember to leave enough space around the tree to accommodate growth, accounting for both vertical and lateral growth. Your number one priority needs to be not hindering the tree’s development.

Also, consider factors like sunlight, shade, and wind patterns when deciding on the deck’s location. A primary benefit of building a deck around a tree is the shade you gain from the canopy.

Therefore, you’ll want to optimize the deck’s location around the tree to get the most shade coverage and protection from the wind. Don’t forget to think about patterns of sunlight on the deck throughout the day as well.

4. Protecting the Tree’s Root System

The tree’s root system is vital for its stability and overall health. When building your deck around nature, you need to ensure you don’t damage the tree’s roots during construction. You can avoid this issue by carefully digging around them and using hand tools or specialized equipment to minimize damage.

You can also opt for innovative techniques like building an elevated deck or using adjustable supports that minimize the impact on the roots and allow them to grow and expand naturally.

5. Ensure Proper Drainage

Another must-do when building decks around natural elements like trees is incorporating proper drainage mechanisms to prevent water accumulation around the tree’s base. This drainage will help maintain a healthy environment for the tree and prevent moisture-related issues, such as root rot.

One way to achieve this is by sloping the deck surface away from the tree, or using perforated drainage pipes to divert water away. In addition, avoid creating structures or barriers that may impede natural water flow to the tree’s roots.

6. Regular Maintenance and Care

Once the deck is constructed, it’s essential to continue caring for both the tree and the deck. Regularly inspect the tree for signs of stress, disease, or pests, and address any issues promptly.

Additionally, maintain a wooden deck by regularly cleaning and sealing the wood to ensure its longevity. As you’ll have leaves falling onto your deck, make sure you sweep these leaves up frequently, no matter what type of material your deck uses.

Uncleared leaves can result in mold and mildew. While wooden decks may sustain more damage, mold and mildew can still cause issues with PVC or composite decks.

To learn more about deck maintenance, read our summer deck cleaning and maintenance article.

Why Use PVC or Composite Decking for Your Deck Around a Tree?

1. Environmental Considerations

If you’re planning to incorporate trees in your deck design, it’s likely because of your environmental consciousness. Therefore, going for a composite or PVC deck is the best option to keep your entire project as environmentally-friendly as possible.

Many composite and PVC deck boards are made with recycled materials and/or are recyclable, or incorporate other sustainable practices. By choosing these materials, you contribute to environmental conservation by reducing the demand for virgin wood and promoting the reuse of plastic or other recycled components.

For example, TruNorth Rice Hull Composite Decking is made using 95% recycled content and requires no trees be cut down.

2. No Harsh Chemicals

Using PVC and composite materials for a deck incorporating trees provides a practical and environmentally-friendly solution. These deck boards require no harsh chemicals for staining, painting, or cleaning, which helps keep your tree and the planet healthier!

3. Stability and Structural Integrity

Composite and PVC decking materials offer excellent stability and structural integrity. These factors are especially important to consider when building your deck around trees. A high level of stability is crucial to withstand the additional challenges posed by tree growth and movement.

Additionally, composite and PVC materials are less prone to warping, twisting, or cracking, which helps maintain the overall stability of the deck, especially when there might be uneven terrain or tree roots present.

4. Resistance to Moisture and Decay

Another benefit of composite and PVC decking materials is that they have an inherent resistance to moisture, rot, and decay. Moisture management is crucial when building decks around trees or other plants, as it prevents issues like rotting or mold growth. These issues can negatively impact both the deck and the tree.

Choosing materials that are resistant to moisture ensures a longer lifespan for the deck and minimizes the risk of moisture-related damage to the tree’s roots.

5. Visual Appeal

As noted above, building your deck around nature creates an interesting and very visually appealing design. For an added visual appeal, opt for composite and PVC decking materials.

These materials often retain a non-faded colour and high-quality appearance for a much longer period than wooden decks.  Even when exposed to sunlight and outdoor elements, most composite and PVC decking brands boast anti-fade technology and even come with warranties against colour fade.

The long-lasting materials ensure that your deck will continue to enhance the overall appeal of your outdoor space, complementing the natural beauty of the tree, for years to come.

6. Fade and Stain Resistance

As just mentioned, composite and PVC decking are highly resistant to fading. They’re also both stain-resistant. If you incorporate a tree into your deck design, exposure to sunlight and potential leaf debris can lead to discoloration or staining on the deck surface.

Using fade and stain-resistant materials ensures that your deck retains its vibrant colour and appearance, despite prolonged exposure to the elements and leaf or other natural debris fall.

7. Pest Resistance

Composite and PVC decking are not appealing to pests, such as termites or carpenter ants. Quality pest resistance is especially beneficial in a deck surrounding a tree, as trees may attract pests.

By using materials that are resistant to pests, you minimize the risk of infestations and protect the structural integrity of the deck.

8. Easy Cleaning and Maintenance

Composite and PVC decking materials are not only easy to clean, but they also require minimal maintenance, especially compared to wood decking materials. If you have a tree integrated into your deck design, regular cleaning may be necessary to remove debris or fallen leaves.

The non-porous surface of composite and PVC decking makes cleaning with just soap and water a breeze, saving you both time and effort in maintaining your deck’s appearance.

9. Long-Term Cost Savings

While the benefits of using composite or PVC decking in your deck design might be attractive, you may be concerned about the cost comparison with wood. Fortunately, these materials offer significant cost-effectiveness over time.

The durability and longevity of composite and PVC decking material lead to substantial long-term cost savings. These materials may have a higher initial cost compared to traditional wood; however, their resilience against the elements and decay ensures you’ll have fewer deck replacements or repairs.

To put it in perspective, a wooden deck typically has a lifespan of around 10 years, while a PVC or composite deck can last 25 years or more, with minimal maintenance costs over that period. Wooden decks, on average, require paid repairs and maintenance every one to two years, adding significantly to the overall cost.

In Conclusion

Building a deck around a tree can be a stunning and unique addition to your outdoor space, allowing you to appreciate the tree’s natural beauty while creating a functional and inviting area.

By following the guidelines in this article, you can ensure your deck is constructed in a manner that respects the tree’s health, preserving both the tree and the deck’s stability for years to come. Remember, always consult with professionals, such as arborists or deck builders, to ensure a successful and harmonious integration of the deck and the tree.

In need of more inspiration for your upcoming deck project? Visit our ‘Get Inspired’ page, which boasts a variety of deck design ideas, including those that seamlessly incorporate nature.

When deciding what material to put underneath your new deck, there are a few options, like gravel, mulch, sand, and soil. But which should you go for? In this article, we’ll cover the pros and cons of each under-deck material so that you can make the best decision for your deck project.  

What Are the Pros and Cons of Different Under Deck Materials?

Before discussing which is the best overall choice, let’s cover the benefits and issues associated with some of the most common materials to put under a deck. 

Gravel Under Decking

The Pros of Gravel

• Good for Drainage

Gravel is a great choice if you want a high level of drainage. As gravel doesn’t absorb moisture, any water under the deck will run off instead of soaking into the material below the deck, potentially causing dampness. Less moisture also reduces the chance of mosquitoes around your deck. 

• Helps with Weed Prevention 

Because plants, including weeds, will thrive when moisture is present, gravel is excellent for weed prevention. If weeds aren’t present below the deck, they won’t be able to grow up through the decking, which can cause damage. A lack of plant life under the deck also helps deter rodents and other small animals. 

• Doubles as a Storage Space

Gravel is an excellent option if you’re looking to make use of the space under your deck. If you have a high deck, you’ll especially want to think about using the area underneath the decking. 

As the gravel won’t hold moisture, it can provide a relatively dry storage solution for your belongings. However, for even greater protection from water and the elements, you may consider using Dexerdry, a patented above floor joist flange gutter system. Dexerdry creates a virtual dry space under your deck, preventing water from penetrating the deck’s surface.  

• Not Flammable 

Another benefit of gravel is that it isn’t combustible. Having non-flammable materials near homes or other buildings is highly important and gravel is one of the best under-deck options for meeting this requirement. 

• Aesthetically Pleasing 

Gravel under a deck is quite aesthetically pleasing as well, giving a clean look. You can also choose from many types of gravel to get the exact look you want. 

The Cons of Gravel

• It Can Be Costly

Gravel is one of the more expensive options when looking at what you can put under a deck. You can find affordable options, like plain crushed rock, but even this can cost more than other options, like mulch. 

Of course, you can also choose from quite highly-priced gravel options if you’re wanting a specific type of gravel to give a certain aesthetic look. 

Mulch Under Decking

The Pros of Mulch

• Inexpensive 

Mulch is generally an inexpensive material to opt for under your deck. Therefore, if you’re looking for the cheapest option, mulch will likely be the best choice. 

• Not Highly Flammable 

While you may think a wood mulch would be flammable, it’s actually not overly combustible. When choosing the least flammable type of wood mulch, opt for coarse materials. Fine wood chips and rubber mulch are the most flammable options when looking at mulch materials. 

The Cons of Mulch

• Retains Moisture 

Mulch will retain a lot of moisture, which can lead to mold, mildew, or fungi growth occurring under your deck. Insects and even rodents and other small creatures may be drawn to the area due to moisture as well. Additional moisture could also cause your deck to rot if using wooden decking or decking that is not capped on all four sides.

Adding a fabric layer below the mulch can help reduce this issue, however, not completely. Opting for rubber mulch instead of wood mulch can also reduce moisture retention and associated problems. 

• Weeds May Grow through the Mulch Layer

The moisture retention capabilities of mulch can attract plants, like weeds, to grow. While weeds themselves may not directly damage your deck, they can potentially cause staining due to the presence of organic matter. It’s important to address weed growth to maintain the aesthetic appeal of your deck. Adding a fabric layer and/or using rubber mulch can be effective in deterring weed growth and minimizing the chances of staining on your deck surface.

• Needs to be Replaced Regularly     

While inexpensive, mulch decomposes quickly and will, therefore, need to be replaced regularly. This will add to the lifetime cost of your chosen under deck material, and replacing the mulch is time consuming. 

As with the last two issues, rubber mulch will suffer from quick decomposition less so than wood mulch, meaning you’ll need to replace rubber mulch less frequently.   

Sand or Soil Under Decking

Sand and soil offer predominantly the same benefits and similar issues. 

The Pros of Sand or Soil

• Inexpensive

As with mulch, sand and soil are relatively inexpensive materials to put under a deck. They’re also both widely available, so you should have no problems finding a supplier if you opt for sand or soil under your deck.

• Not Flammable 

If you’re concerned about your under-deck material being flammable, that’s not something to worry about with sand. This material isn’t combustible and can’t burn, so is unlikely to cause any fire hazard. Soil is also not very flammable, in part because it retains so much moisture. 

• Can Be Used Under Flat Decking

Sand and soil are good options if you’re creating a flat deck, like a decking path, as opposed to a raised deck area. They can be placed underneath the decking boards as a protective area, between the ground and the deck boards. 

The Cons of Sand or Soil

• Not Visually Appealing

If you can see the material under your deck, sand and soil are not as aesthetically pleasing as other materials, like gravel. Generally, sand or soil will only be considered if the space under the decking cannot be seen. 

• Attracts Insects and Animals

Insects, rodents, and other small animals may be attracted to materials like soil and sand beneath your deck. While they are generally more attracted to wooden decks, it’s important to note that our composite and PVC decking materials are designed to be resistant to insect damage. With our decking options, you can enjoy a durable and pest-resistant solution that minimizes the risk of damage, providing long-lasting performance and peace of mind.

Additionally, other creatures, like mice, can cause health hazards and could even attract predatory animals, such as snakes, if they manage to nest or burrow in the soil or sand.  

• Retains Water 

While sand and soil can dry out quickly if they get wet, both will retain a lot of moisture if they continuously get wet, for example, during a period with lots of rainfall. 

This moisture can encourage mold and mildew to grow on your decking and can create an environment for damaging plants like weeds to thrive.  

• Can Erode Quickly

Sand can erode quickly if it’s open to the elements (for example, when used under a raised deck), meaning you’ll need to replace the sand frequently or at least top it up. This takes time and money. Soil will also erode, although generally not at the same rate as sand.

• Plants May Grow Through the Material 

Sand, and especially soil, will encourage plant growth. As with mulch, placing a fabric layer beneath these materials can lower the chance of plants, such as weeds, getting through the material and near your decking.   

What is the Best Material to Put Under a Deck?

In general, gravel is the best material to use under a raised deck. While a little more expensive than some other options, it provides the most benefits. 

It’s not flammable, doesn’t retain water, and is less likely to attract plants, insects, and small creatures. Gravel is also aesthetically pleasing and can be purchased in a range of colours and textures. 

Coarse wood mulch can be a good choice if you want to save some money, although it comes with more issues than gravel. Rubber mulch is less prone to issues like water retention, but is more potentially flammable than coarse wood mulch.

Lastly, sand and soil could work if you’re using decking to create a path or other flat surface, but is generally not considered a good choice under any type of raised deck. 

Types of Gravel for Deck Projects

If you’ve decided that gravel is the best material to put under your new deck, you may be wondering which type of gravel to get. The type you choose will most likely be based on your budget and style preferences. The following are some of the most popular options for gravel to put under a deck. 

• Crushed Stone: this is often crushed limestone. It comes in a naturally neutral colour and is relatively inexpensive. Crushed stone is available in various colours if you’re looking for a certain style, but these unique hues will be more expensive than standard crushed stone. 

This material can also have jagged edges, so may not be the best choice if you’ll be walking over the area (even when wearing footwear).   

• River Rock: this material has a smoother texture with rounded edges, making it better for an area that will be walked on. It’s also aesthetically pleasing and is used a lot for landscaping. However, it is more expensive than crushed stone.  

• Pea Gravel: if you want a small version of river rock, opt for pea gravel. This material has a rounded edge and is easy to walk on. Do note, that due to its smaller size, pea gravel retains water a little more than the above two options and won’t be the best choice if you’re placing the gravel on a sloped area. 

In Conclusion

Deciding what to put underneath your deck doesn’t have to be challenging. This article should have helped you to compare the most common materials to put under a deck, allowing you to make the best decision for your project. If you want to learn more about the best decking materials and answer some more frequently asked questions, explore more of the TruNorth website. We have resources to help you through every step of your new decking project. You can also find an array of inspiration for your upcoming deck installation by visiting our Get Inspired page!