Decks add great style to your garden, and it’s no wonder why so many homeowners choose to have them. However, there is one small but very significant catch. The ground beneath the deck needs to be even.
Can you just lay your decking on uneven ground? No, you can’t, but the good news is you can fix the slope, making it a good base for a deck.
- Have a slope that runs away from your house;
- Have a slope that runs in more than one direction;
- Don’t have a slope, but the ground has bumps and hollows all around,
Then read along to learn how to lay decking on uneven ground.
Method 1: Cemented Support Posts as A Decking Base
This method is best for gardens where the slope moves away from the house.
Make A Plan
There’s a famous saying, “measure twice and cut once”, and nowhere is that more true than in building decks. Here are some pointers on how to plan your deck on a slope so you don’t hit a bump in the road (no pun intended).
- Plot out your area by using stakes and string. Consider the length of your deck boards as much as you can. This will help minimize needles cutting to size later on.
- Allow for gaps between boards. Space between 5 and 8mm should be enough for the boards to expand without breaking during cold weather.
- Plan for stairs by measuring the heights of the slope.
- Mark where the posts will go.
Create A Deck Base
A quality deck needs a solid base, especially if it is built on a slope. This is how to achieve it:
- Remove the top layer of soil and grass from the sector of your garden where the deck will be.
- Go to the top of the slope and dig two post holes. They need to be deep enough so they reach solid soil.
- Place deck posts in these two holes and measure the height from the bottom of the hole to the height of the deck. Leave an extra 30 cm at the end of each post top. Later on, you will cut the extra length off.
- Fill the holes with concrete and wait until they dry. As they dry, ensure the posts are perfectly leveled by checking with a bubble level.
- Tie a string around each post and extend it to where the opposite side of the deck will be.
- Dig holes for the other two posts on the lower part of the slope.
- Place posts there and ensure they are leveled and as high as the posts on top of the slope.
- Tie a string to the posts at the height you want your deck to be. Use your bubble level to make sure the string is level.
- Secure these two posts with concrete the same way you did with the ones on top of the slope.
- Make marks on the ground where the support posts will go.
- Dig holes for the support posts. They should go in the center in between your existing corner posts.
- Place the support posts, level them, and make sure they are vertical.
- Secure the support posts.
- Install the deck beams.
Once this is done, you can build a deck frame and finish the project as you would with every ordinary decking project where the ground is even.
Method 2: Level Supporting Base
This method is suitable for ground that isn’t sloping but is full of bumps and hollows, making it uneven. The overall level is okay, but the imperfections make deck installation tricky, so the soil has to be prepared regardless.
Before you start, you will need the following:
- Type 1 MOT hardcore (crushed carboniferous limestone)
- Wood to be used as frame legs
- Paving slabs that are either old or cheap
When you have these materials at your disposal, you can start the actual work.
- Decide what height you want your decking to be at.
- Mark out the area where the deck will be.
- Dig and remove the soil from the market space. The depth should be about 200mm.
- Add a layer of Type 1 MOT hardcore. Make it about 50mm in depth.
- Build your decking frame to look like a ladder, but don’t place it over the area just yet.
- Lay the old paving slabs on the marked area. Place them along the edges and in a line down the center. Placing them in this formation will create a solid base for your deck frame.
- Place the decking frame over the slabs. Some slabs will not be perfectly level. Screw some off-cuts to places where the decking needs to be elevated.
- Add decking boards on top of the frame and screw them on tightly.
Deck Maintenance is Important
Proper deck maintenance is crucial for the longevity and appearance of your outdoor living space. Regular cleaning and upkeep can prevent wear and tear caused by weather and foot traffic and help prevent rot and decay. One of the most effective ways to maintain your deck is through pressure washing. This powerful cleaning method uses high-pressure water streams to remove dirt, grime, and other debris from the surface of your deck, making it look new again. Pressure cleaning can also help remove any mold or mildew growing on your deck, preventing potential health hazards. By utilizing pressure cleaning as a part of your deck maintenance routine, you can keep your deck looking great and prolong its lifespan for years to come.
- Always make an initial plan.
- Prepare the ground by removing the top layer of soil and making it as even as possible.
- Sloped gardens require fence posts from the top of the slope to the bottom for the frame to be built on them.
- Uneven gardens require the soil to be hardened with Type 1 MOT hardcore and laid with old paving slabs to support the decking frame.