Garden Advice

How to lay decking on a slope and uneven ground

Your garden’s landscaping is an important part of your house. When done correctly, it can look aesthetically pleasing as well as boost the value of your home. Similarly with decking, it can not only add value but can also be a great part of your garden where you gather with friends and family to enjoy some time together. If you’re considering laying decking in your garden but are wondering how to lay decking on uneven ground or how to build decking on a slope, then keep reading!

This post is for you if you:

  • Want to install decking but your garden is uneven, or
  • You want to install decking but your garden is on a slope.

How to lay decking on uneven ground

If your garden is uneven, but you still want to lay a deck on uneven ground, then follow this method to create your decking. Start out by determining where you want your decking to be – do this both in terms of location and height. Once you’ve figured out where you want your decking to go (usually, it will be adjacent to the patio doors that lead to your garden or to a fixed structure of your house), you need to start digging at about 20cm below the current ground level. First, remove the top layer of lawn and then make sure you dig evenly and remove any rocks and stones that might appear. 

Once you’ve prepared the bed for your decking, it’s time to use type 1 MOT hardcore to fill in the new soil bed. This type of material is not easily degraded and consists of solid materials of low absorbency that are used to construct base layers for creating heavy load-bearing structures. It’s usually made up of large aggregates including construction and quarry waste, gravel and crushed rock. Make sure that your 1 MOT hardcore layer is about 5 cm deep in the soil bed. 

Next, you need to add paving slabs to your bed, which will go on top of the 1 MOT hardcore layer and then compact it. Make sure you place these paving slabs along the sides of the soil/MOT hardcore bed as well as in the centre. They will act as the support for your decking’s framing. 

It’s now time to create your decking frame, which will go on top of your soil bed. Use solid planks to create a rectangular or square shape, depending on your decking preferences, and then screw in planks in the middle for support. Once you’ve done this, you need to add more wooden planks to act as the “ribs” of your frame in order to offer it more support. 

When ready with your frame, place it on top of the MOT hardcore and paving slabs. You’re now ready to add plywood or another type of material to provide a place for stepping on. Use wooden screws to secure these sheets to your decking’s frame.

Finally, add a wood varnish to seal the wood and to create the colour effects you are looking for.  

How to build an elevated deck on uneven ground

Building an elevated deck on uneven ground requires some prior preparation. You will first need to purchase sturdy wooden poles on which to secure your decking’s frame as well as ready mix concrete. This is in addition to the wood required for the decking frame as well as your premade risers for the stairs and wood for your railings. As a finishing touch, you’ll need wood varnish to give it the colour you want and to protect the wood.

Planning is key here and you will want to measure out the area where your new decking will go. Once this is determined, you need to dig four holes in your garden which will form the perimeter of your decking. Sometimes more holes will be required, depending on the size of the decking and the support you will need for it. Add one wooden pole in each of the four holes and then add the ready mix concrete to the holes, giving it time to set and harden. Don’t worry about the height of the wooden poles yet. You will use a saw later to level them once the decking frame has been installed. 

When the concrete has set, place your pre-made decking frame with supports within the perimeter of the four (or more) supporting poles and secure the decking to the poles using wooden screws.

It’s now time to add plywood (or another type of wooden sheet) to cover the decking frame and make it possible to walk on it. When ready, make sure you saw off the parts of the supporting wooden poles that stick out of the ground so that your decking is even. 

Next, you will need to create the stairs using stair risers. Make sure you start with the bottom stair first and work your way up. 

Finally, add the railings so that young kids, or anyone else for that matter, don’t fall off the decking. 

As a finishing touch, varnish the wood with a suitable material. 

How to build decking on a slope

Whether you’re wondering how to lay decking on a slight slope or how to build decking on a sloped garden, the process is quite similar to what was mentioned above in the section on “How to build an elevated deck on uneven ground”. Building a deck on a slope requires prior preparation and purchasing the right materials. Other than that, the process for building decking on a slope is the same as the one described above.   

Contact the professionals

Working on your own decking can be a very rewarding and enriching process. But it’s not for everyone. This is why if you don’t have the free time or the right mix of skills to lay the decking on your own, feel free to get in touch with the Fantastic Services experts, who can take care of it for you quickly, efficiently and professionally. 

Need a professional landscaper?

Find a professional to take care of your decking!

Add a valid postcode e.g. SE1 2TH


  • Do prior preparation and gather your materials
  • Measure, measure, measure
  • For decking on uneven ground, you’ll need MOT type 1 hardcore, paving slabs and the wooden decking frame together with the right wooden sheeting to cover the frame
  • Once the frame has been put into place, add your railings
  • For decking on a slope, you’ll need ready mix cement, wooden poles, your decking frame and screws to put it all together securely
  • You’ll also need to add stair risers for the stairs
  • Don’t forget to add your railings 
  • Once ready, consider varnishing the wood so that it doesn’t rot or become damaged as quickly due to the natural elements 

Did you enjoy this post? We’d love to hear your thoughts! Feel free to leave your comments below!

Image source: Shutterstock / ungvar

0 0 votes
Article Rating
Notify of
Inline Feedbacks
View all comments
Would love your thoughts, please comment.x