How do they build very high walls

Building a garden wall: practical tips and tricks

Privacy protection, terrace edging or slope support - there are many arguments in favor of building a wall in the garden. If you plan this correctly and bring a little manual skills to the construction, the garden wall will be a real gem and a great design element.

Building a garden wall: the most important things in brief

Garden walls require a continuous strip foundation made of concrete and compacted gravel, which reaches 80 centimeters deep and therefore frost-free into the ground. The thickness of both layers depends on the height of the wall. The wall thickness should be a third of the height at the base. A tightly stretched wall cord and a spirit level help to check the position of the stones. So that the garden wall is stable, the vertical butt joints of the individual rows of stones should always be slightly offset. By the way: Inquire before building whether requirements and regulations have to be complied with!

Different variants of garden walls

Garden walls fit into every garden and can even be built in the smallest of spaces. Depending on the type of construction, they support slopes and thus create additional flat surfaces. They protect against prying eyes, keep uninvited visitors away, store the sun's heat and release it again in the evening - so where better to place a garden bench than in front of a garden wall. With low, about knee to waist high garden walls, raised beds can be built, seats and terraces can be bordered and they serve as seating or storage space at the same time. Higher garden walls can be decorated with climbing roses or wall fountains.

Free standing garden walls

Garden walls can either stand freely in the garden or lean their backs against a slope as a retaining wall or stand in front of it. Free-standing garden walls, on the other hand, have two visible sides. If the bricks you want only have one beautiful side, build two rows of walls so that the wall always shows its most beautiful side. Fill gravel into the cavity between the rows of stones.

Dry stone walls

In the case of garden walls, you can either connect the stones with mortar or build the wall as a dry stone wall. Dry stone walls hold by cleverly stacking the rows and the weight of the stones and are often built as a retaining wall on a slope, which is why such walls are built at a slight incline - about ten centimeters slope per meter of wall height. Dry stone walls are easier to build, but not as stable as mortared garden walls. Up to a height of one meter, dry stone walls can easily be built on your own. A foundation of compacted gravel that is 30 centimeters deep is sufficient. Should the earth still give in slightly under a dry stone wall, its flexible structure easily compensates for this.

Garden walls with mortar

Garden walls built brick by brick with mortar are more durable than dry stone walls, look more even, are more stable and can therefore be taller. Even concrete blocks are ideal for building, but of course it also works with irregular natural stones, where you can compensate for slightly different stone heights with mortar - the joints then become wider or narrower accordingly. You can easily build free-standing walls up to one meter high yourself.

If you build the garden wall as a retaining wall on a slope, it is particularly vulnerable to frost from water seeping in from the ground. Define the backfilling of gravel with fleece from the garden soil and divert seepage water away from the foundation by laying a drainage pipe - for example in a drainage shaft created for this purpose, i.e. a deep hole filled with gravel.

If you work with mortar, the garden wall needs a stronger foundation with 80 centimeters of frost-free foundation, after all these garden walls are not flexible and have to be perfectly anchored.

Garden walls as a blender

Unsightly facades, chimneys, parapets, concrete walls or other existing walls can be concealed with facing walls or a front wall and then look like solid natural stone walls. The facing bricks are glued directly to the wall with special wall adhesive and the joints between the bricks are filled with mortar. A so-called front wall is a separate, narrow wall a short distance from the facade. Both types of wall are attached to the existing wall with wall anchors.

Practical video: How to build a concrete stone wall with a natural stone look

In this video, MEIN SCH├ľNER GARTEN editor Dieke van Dieken and landscape gardener Dirk Sauter show you how to build a concrete stone wall with a natural stone look.
Credits: MSG / CreativeUnit / Fabian Heckle

Suitable stones for building a garden wall

You can build garden walls from natural stone or concrete blocks, which are often deceptively realistically modeled on the natural stones and are much cheaper. Clinker and bricks are also suitable for building. The main difference between clinker and untreated brick? Clinkers are impermeable to water, bricks are not. Therefore, bricks are usually still plastered. Concrete blocks offer by far the greatest scope for design, the best price-performance ratio and, due to their uniform shape, are much better than natural stones for free-standing garden walls that can be seen from several sides.

With unprocessed natural stones (left) something has to be "puzzled" during construction, split stones (right) are layered in a similar way to concrete blocks

Natural stones are available in different processing stages: Largely unprocessed and irregular quarry stones come directly from a quarry. If you split the stones and bring them into shape so that they have almost straight sides but uneven surfaces, you are dealing with so-called masonry stones. Sawn or otherwise industrially processed system stones are regular and are particularly suitable for mortared walls, while rubble stones are usually built into dry stone walls. The following natural stones have proven themselves for mortar:

Do I need a permit to build a garden wall?

Before you build a garden wall, you should ask the building authority whether you have to observe any requirements or regulations. Because a garden wall represents a structural system and is therefore subject to legal regulations. In addition, for garden walls from a height of two meters, proof of stability by a structural engineer is required. But from a height of 120 centimeters you should let professionals do it or at least get advice from a specialist - even if you want to build the garden wall yourself.

Unfortunately, there is no uniform nationwide building law, the regulations for building a garden wall can therefore vary depending on the federal state or even from municipality to municipality. The legislature also differentiates between privacy and border walls to mark the border. As a rule, privacy walls up to 180 centimeters high in the garden do not require approval. These must keep a limit distance of 50 centimeters.

Things look different at the property line, where neighborhood law applies in addition to building law. It is crucial, for example, whether the development plan provides for open or closed construction methods, i.e. whether the boundaries are to be kept clear. Garden walls fall under the closed construction method and even the type of stones can be specified in the development plan. Do not start building, but discuss your building project with your neighbors. It's just stupid if you want to build the wall precisely because you don't want to have anything to do with them. But then you have to go through it to avoid even more trouble.

Build the foundation for the garden wall

The foundation is the most complex part of building a garden wall, but it is also a crucial one. Errors in the foundation are carried over to the entire wall and endanger the stability. Garden walls need a continuous strip foundation made of concrete as a secure base, which extends 80 centimeters deep and therefore frost-free into the ground. Of course, the foundation does not consist of concrete to this depth, but also has compacted gravel as a frost-proof support layer.

The thickness of both layers depends on the height of the wall: If you want to build the wall only four rows high, you can get by with a 30 centimeter deep strip foundation made of compacted gravel. With 75 centimeter high garden walls, you need 55 centimeters of gravel and 25 centimeters of concrete. With a 150 centimeter high wall it is 45 centimeters of concrete, but only 35 centimeters of gravel, with two meter high walls it has to be a good 70 centimeters of concrete.

The wall thickness should be a third of the height at the foot, which also determines the width of the foundation - it should protrude a good five centimeters on all sides. In the case of free-standing garden walls, the lowest layer of stones should be embedded a few centimeters deep in the concrete foundation so that the wall is laterally stabilized.

Step by step to the foundation

First dig a trench 80 centimeters deep, fill in the gravel and compact it with a hand rammer. If the ground is sandy and crumbly, build a simple form of wooden boards into which you pour the concrete. Additional reinforcement in the concrete is only necessary for high walls. It is faster with hollow formwork blocks that are placed in the trench and filled with concrete. Loamy soils are firm enough that you can just pour the concrete into them. If you don't feel like doing concrete work, you can also lay special foundation stones in the trench. The foundation has to harden for two to three weeks and is then resilient

The first row of stones should be a little below ground level in the concrete of the foundation, but the stones must protrude above ground level - this provides additional stability. There are special mortars for natural and concrete blocks. When laying the wall, orient yourself on a tightly tensioned mason's cord and check the horizontal and vertical position of the stones with a spirit level. The first row of stones is the most important; all others are guided by it. Apply a five-centimeter layer of mortar to the foundation, press the first stone into the mortar and tap it lightly with the handle of the trowel - you can also use a rubber mallet for larger stones. With each additional stone, you also apply mortar to the side with which it hits the neighboring stone and press the stone into place. For all further rows of stones, apply a two to three centimeter thick layer of mortar to the previous row and do the same.

Install horizontal barrier

If the subsurface is damp, first install a strip of bitumen sealing membrane as a water barrier, which you place on a thin layer of mortar and then cover with mortar. To protect against moisture, you can also brush so-called sealing slurry onto the foundation and then start with the mortar.

Brick row by row

Always work in dry weather, rain hardly allows precise work. Each row of stones is followed by a layer of mortar, then the next row of stones. This creates different joints: between the layers are the horizontal and continuous bed joints, within each row of stones there are vertical butt joints. These must not lie on top of each other from row to row of stones, otherwise four stones each meet in so-called cross joints - the wall would not be stable in itself. With irregular natural stones you can shape individual stones with a wide chisel, with concrete stones you can start building straight away.

Remove the overflowing mortar immediately with a trowel. Important: You need a so-called joint iron for the joints so that they are completely and evenly filled. Do not press the mortar into the joints or jiggle it around with it, but just pull it smooth over the entire length of the joint. The joints can also be reworked afterwards. Free-standing walls are also finished with cover plates that hold back moisture from above.

Finally, wipe the entire wall with a wet sponge and remove any mortar residue from the stones. Then protect the garden wall for two weeks with a tarpaulin from blazing sun or heavy rain, after which the mortar is dry and the wall is ready.