Build a patio on a slope and it can be a real focal point in your garden design, offering an elevated view, an intimate sunken space or even several terraces
Finding out how to build a patio on a slope is one of the first things to consider if you have multiple levels in your garden, especially if there's currently no place to gather for relaxing and entertaining. When landscaping a sloping site you will want to create at least one flat terraced area to turn into a usable space for a patio.
A sloping site can easily be turned into an advantage as it gives you the opportunity to create a standout patio design idea as part of your landscaping. You can even create an elevated patio to offer spectacular views or a sunken one to create a cosy space to gather. As you will need to accommodate a table and chairs, as well as a paved area, it will be necessary to level the ground, as well as work out how to access the patio from the surrounding garden.
You could attempt to take on the project yourself if you're a confident DIYer and have people to help. But depending on the site and degree of difficulty, building a patio on a slope may need a professional construction team to avoid problems with key issues like drainage and foundations, where it's easy for things to go wrong so you're less than happy with the outcome.
1. Assess the slope and work out the gradient
Work out the exact gradient you have to deal with(Image credit: Border Oak / Jeremy Phillips)
Coming up with a patio design as part of your sloping garden ideas can be tricky but as long as you follow a few key points landscaping on a gradient can be immensely rewarding.
"The first thing to do when it comes to designing a patio in a garden like this is assess the slope properly," says technical product specialist Jack Middleton. "A gentle incline might only need some minor levelling, but steeper gardens will usually need terracing or retaining structures to create flat, usable space."
Measure the exact gradient of the slope using a spirit level – this Stanley heavy-duty spirit level from Amazon is a best-seller. Gentle slopes with only a slight incline are the easiest to deal with but will still need levelling for the purposes of building a patio, as it will need to be completely flat. This could involve taking away soil or alternatively require more soil to create the desired level. This is a project you could consider doing yourself if you have the right skills and expertise.
If you're planning a patio on a slope greater than 1:4 (25%) this will generally require a professional assessment as retaining walls and steps to form a terrace may be needed. Measuring and building them is skilled work, at both the design and construction stages, so it's good to include professional landscapers in the conversation.
Jack Middleton
Jack Middleton has expertise in product design and installation for Sunopy. This experience has given him the technical and practical knowledge to advise on patio builds in challenging landscapes to create innovative, functional outdoor spaces.
2. Do the necessary groundwork
Good foundations are everything when building a patio on a slope(Image credit: LSOphoto Getty Images)
When drawing up plans for building a patio on a slope, consider budget and how long the project might last. When altering slopes it's important to think about where water and gas pipes, as well as electrical cables, are to avoid expensive mishaps when excavating the ground. Factor in extra expenses like hiring earth moving machines and earth removal services too, especially if you're considering a raised patio idea.
If you're working with anything other than a gentle slope, multi-level patios on terracing might be the solution. They are generally cheaper than one-level patios on steep slopes, while also providing a larger usable area.
"The main downside of building a patio on a slope is cost," says Tyler Mullen, manager at Pro-Tools. "Excavation, structural support and drainage all add to the total. Retaining walls need to be properly constructed and may require professional input, especially if the slope is severe. There’s also more labour involved in levelling the ground and transporting materials."
Tyler Mullen
Tyler Mullen has significant expertise in DIY, home improvement and custom builds, making him a valuable resource for patio projects. His technical prowess and hands-on experience in construction give him a bank of knowledge to tap into.
3. Plan the right drainage for your sloping patio
A French drain is one of the options to deal with standing water(Image credit: Marina Sidorova/Getty Images)
How to get patio drainage right is always a concern, and even more so if you're dealing with a patio on a slope. Investing in a patio can be an expensive outgoing so make sure you factor in the right drainage at planning stage to avoid problems later on.
"If you're building a patio in a sloping garden, it's important to remember they are still vulnerable to standing water and other drainage issues," says drainage expert Jess Thomas, managing director of Drainage Central. "When planning drainage for a sloping patio, there are several techniques that you should consider using."
Channel drains (also known as trench drains) are good for placing at the bottom of sloping land where you may be building a patio, says Jess. "They are usually narrow, and can be easily disguised with plants if you're concerned about their appearance.
"Without channel drains, there is a chance that water can pool at the bottom of a sloping area, which can be a problem if you have flowerbeds or walkways there. This technique is easy to install, and it can effectively redirect water to an area where it can drain away properly."
Alternatively a French drain can be used if you want to cover the drainage system with a layer of grass to hide it. Similarly to channel drains, a French drain will work best if it is placed in an area where water is prone to collecting, such as at the bottom of a slope.
"If you have several levels to a sloping garden or patio, you can combine French drains with vertical drains to keep the slope dry and stop water from gathering in specific areas," says Jess.
Jess Thomas
Jess Thomas is managing director of Drainage Central and a recognised expert in the drainage and plumbing industry. He is dedicated to helping homeowners find effective solutions to their drainage problems.
4. Work out if you need a retaining wall
One of the uses for retaining walls is to create tiered patios in steeply sloping gardens(Image credit: Jacky Hobbs)
Retaining wall ideas are an effective type of drainage for a patio on a slope. They are designed to hold back soil in multi-level garden layouts, and encourage draining by creating spaces where the water can flow through the landscape. They are key if you want to build sunken garden ideas too.
"A retaining wall can also be used as a natural vertical drain, and they only need a small amount of gravel to allow water to flow down into a pipe or another outlet," explains Jess Thomas. "Most people will use retaining walls alongside other methods, such as channel or French drains, in order to keep water moving."
You'll want to find out how to build garden steps too as this will add another layer of interest to your multi-level layout.
5. Lay patio slabs with the correct slope
A patio on a slope only needs a slight pitch, enough so water drains, but not enough that you notice when walking or sitting on it(Image credit: Steved np3/Getty Images)
One of the most common mistakes when designing a new paved patio is not getting the level right. This can create problems, particularly with pooling water.
It's crucial to create a level surface for the pavers while also allowing for water runoff, typically with a slight slope away from the house. At first glance, although a patio looks level, they are designed to have a slight slope to ensure proper drainage.
"When laying slabs, make sure they fall away slightly from the house to direct water into your drainage channels," says Jack Middleton. "Get that angle wrong, and you risk pooling or even water damage near your foundations."
FAQs
What is too much slope for a patio?
When considering what is too much slope for a patio the first thing to factor in is the bigger the slope the greater the cost compared with flat installations. This is because you will need skilled construction experts and special equipment, and the project will likely take longer to complete.
"While there’s no exact limit regarding what is too much slope for a patio, anything steeper than 1 in 10 usually needs significant structural work," says Tyler Mullen, patio build expert at Pro Tools. "At that point, a multi-level layout might be more practical than trying to create one large flat area."
Don't let sloping patio mistakes ruin your design through lack of planning and foresight. Building a patio on a slope is a big job so if the project starts to feel daunting it could be time to call in the professionals.
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Lifestyle journalist Sarah Wilson writes about flowers, plants, garden design and gardening trends for Homes & Gardens. She has studied introductory garden and landscape design and floristry, and also has an RHS Level 2 qualification in the Principles of Plant Growth and Development. She is a regular contributor to Homes & Gardens and Livingetc. She has also written for Real Homes, Modern Gardens, Country Living, and Country Homes & Interiors magazines. Her first job was at Elle magazine, during which time a trip to the beautiful La Colombe d'Or in St-Paul-de-Vence led to an interest in writing about all things botanical. Later as lifestyle editor of Country Homes & Interiors, she loved the captivating country gardens that were regularly featured.
