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Build a Fire Pit in Your Back Garden

There’s nothing like a crackling fire on a summer evening to draw friends and family together. A well-built fire pit can extend the amount of time you spend outdoors and improve your garden as a social area. They’re also surprisingly easy to build, even if you’ve never tried bricklaying before.

Always check whether there are any local ordinances or restrictions before you begin a major building or landscaping project.

Dig Your Pit

To begin your fire pit, you need to mark out where you’d like to dig it. It’s important to get in touch with your utility company to find out whether there are any parts of your garden to avoid, and make sure that you have plenty of clearance so that you’re not in danger of setting fire to any trees or a pergola.

A 900mm (3ft) diameter fire pit is an excellent size – it offers a large fire but doesn’t space people too far apart. Once you’ve marked your circle, dig a hole around 200mm (8”) deep and 75-100mm (3-4”) wider than you want the interior of the pit to be.

Pour a Concrete Base

A concrete base will keep the sides of your pit from cracking as the ground moves over time. Stake the forms into the pit that you’ve dug – the first (outer) circle should be 1200mm (4ft) in diameter and the second (inner) circle should be 900mm (3ft) in diameter. This means you have a 300mm (1ft) circle in between to pour the concrete into. Fill the forms halfway and press a rebar ring into the concrete for strength. Finish by filling the forms up to the top and tap the tubes with a club hammer until the concrete is level.

Let the concrete set overnight and remove the forms.

Build Up Inner Firebrick Walls

It’s a good idea to use firebrick or refractory brick to build the inner walls of your fire pit – this is because regular bricks crack at high temperatures. Fire bricks are denser than regular bricks and are kilned to withstand the heat of a fire pit. It’s a more expensive option but it means that your fire pit will last longer. You’ll need around 25 firebricks for a 900mm (3ft) fire pit.

Mortar the bricks with refractory cement, which usually comes pre-mixed. Trowel the cement on in a thin layer and use the tightest joints you can to reduce the amount of air in between the bricks. Remember to place gaps for draw holes at four opposite points around your fire pit. Check that the bricks are level regularly so that you can still adjust while the cement is wet.

Build the Outer Walls

You have a lot more flexibility in the outer wall materials since they won’t be subject to such extreme temperatures. Some people like to build them out of the same material as their paving or other garden walls to make sure that everything matches. You’ll need around 80 standard-sized bricks for a 900mm (3ft) pit.

Level your bricks in between courses by tapping down when necessary. Again, check the level regularly to make adjustments while the mortar is wet.

Finish the Top Lip

To finish your pit, use the same brick as the outer wall to create a cap that covers both the outer and inner walls. This will protect the wall joints from rain and keep any sparks contained within the pit. It also means you’ll have a warm ledge to rest your feet on or put your plate on.

You’ll need to give your brand new fire pit around a week to set before you can light a fire. Make sure to pour a few inches of gravel into the base for drainage, and don’t forget to buy a few marshmallows.