Best Way to Install Pergola Posts: Concrete or Not?
Should you set pergola posts in concrete? The short answer is: it depends on your ground, location and pergola design.
Concrete offers maximum stability, but modern post anchors and ground systems can be just as effective in the right conditions. With the UK’s mix of rain, frost and shifting ground, choosing the correct fixing method is essential if your aluminium pergola is going to stay level, secure and problem-free for years to come.
Introduction: Planning your pergola? Here’s how to secure it
When planning a pergola, one of the biggest decisions is how to secure its posts. Should you use concrete for a rock-solid foundation or opt for an alternative method? This guide covers both approaches and helps you choose the best option for your UK garden based on soil, weather and pergola type.
Concrete vs post anchors: which is right for you?
- Choose concrete if your pergola is large, permanent, in a high-wind area, or supporting a louvered or solid roof.
- Choose anchors or ground screws if you’re installing on paving, renting, working with lightweight aluminium pergolas, or want easier future removal.
If you’re unsure, a properly specified aluminium pergola system can often work with either approach. That’s where design, soil type and fixing method all come together.
Pergola post installation methods explained
Concrete Installation
The traditional approach
The most common method is setting posts in concrete footings for maximum stability. This approach is widely used in the UK due to frequent wet and windy weather.
Types of concrete footings
- Poured-in-place concrete footings: Provides a solid, custom base for each post.
- Pre-cast concrete footings: Pre-made blocks that can be placed in pre-dug holes, reducing drying time.
Process overview
- Dig a hole approximately 600mm deep (adjust for local conditions and frost risk).
- Add a layer of gravel at the base for drainage.
- Place the post and fill the hole with concrete.
- Ensure the post is level and allow the concrete to cure.
Non-concrete installation
Alternatives to concrete
Several non-concrete options provide stability while improving drainage and making future adjustments easier:
- Post anchors and metal spikes: Metal sleeves driven into the ground to hold the post.
- Screw piles / ground screws: Helical ground anchors that provide strong footing with minimal digging.
- Gravel footings: A gravel-filled hole that allows for better drainage and flexibility.
Examples you may see in the UK
- Bolt-down post bases: Ideal for securing pergola posts to patios and hardstanding.
- Ground screw systems are commonly used for pergolas, decks and garden rooms where minimal ground disturbance is required.
Process overview
- Drive or screw the anchor into the ground.
- Secure the post to the anchor using bolts or brackets.
- Check for level and alignment before final tightening.
Pros and cons of concrete pergola post installation
Advantages
Superior stability and strength
Concrete creates a sturdy, immovable base, helping prevent movement in strong winds.
Longevity and durability
Concrete footings provide excellent resistance to movement caused by wind and ground settlement. However, posts should not be buried directly into concrete without protection, as trapped moisture can accelerate rot in timber and corrosion in untreated metals.
Suitable for heavy pergolas
If your pergola is large or supports climbing plants, concrete footings can provide the required reinforcement.
Disadvantages
Labour-intensive and time-consuming
Concrete requires digging, mixing, and curing time, making installation a longer process.
Less flexibility and difficult removal
Once posts are set in concrete, adjustments or removals are challenging.
Potential for frost heave
Water in the ground can freeze and expand, causing movement if footings are too shallow or drainage is poor.
Pros and cons of non-concrete pergola post installation
Advantages
Easier and faster installation
No need for digging deep holes or waiting for concrete to set.
Greater flexibility and easier removal
If you plan to relocate or adjust your pergola, post anchors allow for modifications.
Reduced environmental impact
Less concrete often means a lower carbon footprint and improved drainage.
Disadvantages
Less stability in certain conditions
Softer soil or high-wind areas may require additional bracing.
Potential for shifting and settling
Posts secured with anchors or gravel can shift over time, requiring adjustments.
Shorter lifespan in some cases
While durable, some alternative methods may degrade faster than concrete footings depending on materials and exposure.
Factors to consider when choosing
Soil type and conditions
Sandy soil
May require deeper footings or screw piles to prevent shifting.
Clay soil
Can expand and contract; concrete with good drainage is often the safest option.
Rocky soil
Difficult to dig for concrete footings, making screw piles a strong alternative.
Existing patios and hard surfaces
If your pergola is being installed on porcelain tiles, concrete slabs or a composite deck, bolt-down post bases are often preferable to digging new footings. These allow secure fixing without disturbing drainage layers or damaging finished surfaces.
If you’re fixing to porcelain tiles, this step-by-step guide explains how to anchor a pergola securely without cracking tiles or compromising drainage.
Pergola size and weight
Small vs. large pergolas
Smaller pergolas may work with post anchors, while larger structures often benefit from concrete.
Material weight
Heavy timber or larger roof systems require stronger fixings to support the load.
Climate and weather conditions
Frost heave zones
In colder regions, deeper footings and good drainage help reduce freeze-thaw movement.
High wind areas
Concrete footings or properly specified structural anchors help resist strong gusts.
Budget and DIY skills
Cost considerations
Concrete footings can cost more due to materials and labour, while anchors and screw piles are often faster and more cost-effective.
DIY feasibility
Non-concrete options are often more beginner-friendly, while concrete requires correct mixing and levelling.
Step-by-step installation tips
Concrete tips
- Hole depth: Ensure holes are deep enough (often around 600mm) and sized appropriately for the post and load.
- Concrete mix: Use a weather-resistant mix and consider a post sleeve or base to reduce moisture contact.
Non-concrete tips
- Match fixings to your ground: Select anchors suited to your soil type and pergola size.
- Get the layout perfect first: Use a spirit level and check diagonals before final tightening.
For patios, rentals or non-permanent installs, you may also want to explore fixing methods that don’t involve drilling at all.
Conclusion: making the right choice for your pergola project
Both concrete and non-concrete fixing methods can work well. The right choice depends on your ground conditions, exposure, and pergola design.
For windy locations or heavier roof systems, concrete or a load-rated structural fixing is usually the safest option. For patios, lighter pergolas, or installations where flexibility matters, anchors and ground screws can be a practical and reliable alternative when specified correctly.
Other articles our customers have found useful
- A quick guide to preparing the ground area for your pergola
- Pergola assembly and installation options
Not sure which fixing method is right?
Our team can advise on post fixings, ground conditions and layout before you commit. Whether you’re planning a surface-mounted pergola or a full concrete installation, we’ll help you get it right the first time.
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