The wood furnace for the garden

A rustic wood furnace in the garden is the dream of many home-owners, whether as a pizza oven, for preparing crusty wood stove bread or a juicy roast. If you want to build it yourself, you need a lot of craftsmanship, a kit including building instructions makes the work easier.

When the temperatures climb in spring at the latest, the barbecue season begins for many. Sitting outside with family or friends and enjoying delicacies such as sausages, steak or vegetables over a wood fire. If you are the proud owner of a wood furnace, you can serve up even more delicacies. He can use it as a bread oven or pizza oven, he can prepare tarte flambée, juicy roast meat, crispy roast pork or various casseroles. Such a brick stove can either be built completely by yourself according to instructions or a picture, which makes it unique in any case, but also requires craftsmanship. Alternatively, many manufacturers offer very good kits or you can buy a completely finished wood stove for cooking and baking outdoors.

Depending on what is to be prepared in the wood-burning oven, what is to be baked, cooked or roasted, the size of the baking surface varies. A pizza, a tarte flambée or a loaf of bread can be prepared wonderfully on a baking surface of 30 by 30 centimetres.  If the baking surface is twice as large, namely 60 by 60 centimetres, there is enough space for four pizzas or tarte flambée or four to six loaves of bread. You can also comfortably accommodate several roasters, Roman pots or pans. 

Permits are required for a brick stove in the garden or yard, because it is a "stationary" object that is not removed in phases, for example in winter. If you cannot remove your wood stove at any time, you do not need a permit because the installation is not covered by the building regulations. However, neighbouring law prescribes consideration. If you build a small house around your wood stove, for example as a weather shelter, this may require both a building permit and regular maintenance by the chimney sweep. If you want to build without a permit, you must keep a distance of three metres from the neighbour's boundary and/or from public areas. In addition, the furnace must not exceed a certain volume and maximum height. The limits vary from federal state to federal state. Information can be obtained from the district chimney sweep or the local building authority. If you are renting, you should also inform the owner of the house or ask for permission. The system may have to be dismantled when you move out, which can be time-consuming.

Once a wood stove is in place, it cannot be moved easily. The location of the wood furnace should therefore be carefully considered before setting it up and buying materials such as sand, gravel, clinker bricks and fireclay mortar. Such a stove is also a semi-open fireplace. It emits smoke and is always a conceivable fire hazard. Place it always at an appropriate distance from the house or other buildings - but of course still be easily accessible. A long exhaust pipe or flue pipe can otherwise prevent smoke from soiling the house façade. If there are children near the wood stove, this pipe should be insulated to prevent injuries. The flue pipe can become very hot. 

The basic framework for a self-built furnace is mainly made of bricks, but clay is also used. How much material you need depends on the size of the stove.  

Basically there are two ways to fire a wood stove: Directly in the baking chamber, where the food is also baked and cooked, or indirectly in a separate firing chamber.

Once the site for the new wood stove has been chosen, the foundations must be laid. Because a brick stove can be really heavy, the foundation must be really solid.  It should be dug between 20 and 80 centimetres deep, depending on the nature of the soil. The rule is: the loamier, the deeper. The soil is then covered with a layer of gravel and cemented. If you put some iron in the foundation, you can be sure that the foundation will not break later, even in heavy frost. Bricklaying can only begin when the cement has dried and hardened properly, which can take around 14 days.

• Building a base: it can either be brick on brick or poured concrete.
• Building the combustion chamber: fireclay bricks are joined together with fireclay mortar, leaving a round gap of about ten centimetres for the flue.
• Clinking the oven: plaster the fireclay combustion chamber with a thin layer of fireclay mortar so that the clinker bricks do not directly adjoin the fireclay bricks. Then brick up clinker bricks all around the baking chamber, with the smallest possible joints between the bricks. 
• Wall up the flue: The area around the flue should be slanted, so the bricks are always moved a little further inwards. The flue should protrude clearly from the stove, otherwise it will draw poorly and it will take a long time for the fire to burn properly. You can also buy the complete element for the flue separately and build the rest yourself the way you want it.
• Inserting the stove door: The stove door can simply be set up or connected firmly with clinkers around the stove by a frame. However, this construction method is highly susceptible to frost. Alternatively, there are sliding doors that stand on two small rails at the bottom and have a useful wooden handle.

If you don't have enough manual skills or don't quite trust instructions from the internet, you can also use a prefabricated kit to build your brick stove. These are often made of refractory concrete or fireclay bricks and you still need a little skill, but there is no need for planning or sourcing materials. Baking on fireclay is particularly popular because fireclay is very porous, which means the stone absorbs moisture well and passes it on to the food being baked, resulting in a crispy crust and juicy interior. Prices for wood-burning oven kits start at around 1,500 euros for the very simplest and smallest version and often exceed 2,000 euros. For a large freestanding oven, the costs are even significantly higher. 

Whether self-built or prefabricated, an outdoor kitchen is of course really fun when the weather cooperates. If you can roof over your outdoor kitchen, you have a certain amount of protection from the weather, and the appliances can be permanently installed. In addition, a patio roof or pergola also prolongs the life of the equipment. Resistant materials such as teakwood, stainless steel or granite are generally recommended. Brick outdoor kitchens are particularly durable. However, it is not only rain, snow or frost that can damage outdoor kitchens; sunlight and UV rays also take their toll on the material. If, on the other hand, the open-air kitchen stands unprotected in the middle of the garden, the electronic equipment must either be well secured or movable, i.e. quickly stowed away in the shed, for example.