Lay slabs (stone slabs) correctly

Stone slabs are decorative, almost indestructible and (apart from their weight) they are extremely easy to lay. However, the preparation of the subsoil requires meticulous work, as otherwise the stone slabs are uneven and waterlogging could form on or under the slabs. In addition, the nature of the subfloor affects the ways in which the slabs can be laid.

Requirements for the slab substrate

The substrate on which the stone slabs are to be laid must be firm, smooth and frost-free. In addition, it must either have a certain incline, be made of materials through which water can seep, or have special drainage. A possible substrate can be concrete. However, a concrete substructure requires its own drain and/or one after a gradient of at least 1.5 percent

drainagesystem. In addition, the construction of a concrete substructure is very expensive due to its material alone. Furthermore, it can be a real challenge for laypersons to ensure an optimal gradient depending on the size of the concrete surface. In addition, with a concreteunderground, the drain of which is connected to the sewage system or which slopes towards a public area, are subject to sewage fees.

On the other hand, concrete substrates are ideal for laying the stone slabs with the help of so-called slab supports, which is probably the fastest and easiest laying variant of all. This variant also has the advantage that the panels can be removed just as quickly and easily if necessary. The downside, however, is that a stone surface is formed using said slab bearings usually does not withstand excessive loads, since there are cavities under the panels condition. Another type of laying that is suitable for concrete substrates and especially for natural stone slabs is often used is to lay the slabs firmly in a mortar mass, comparable to tiles, and to fill in the gaps between them finally to be provided with joint compound, whereby this type of laying is ultimately also possible with the most common underground variant is.

The most common underground variant

In the most common underground variant, the stone slabs lie on a bed of coarse gravel and fine grit. In order to create such a substrate, the entire surface on which the panels will later lie must be covered should dig a pit either by hand with a shovel or with a rented small excavator become. The depth of the pit depends on the desired fill level, which in turn depends directly on the expected load. A depth of a good 40 cm is considered appropriate for parking lots and driveways. However, if the slab surface is to reach the house, the pit should be another 30 cm deeper be excavated because the finished floor is at least 30 cm below the upper limit of the barrier layer must lie.

Before starting to dig the pit, it is a good idea to stake out the exact dimensions with corner posts and cords. If the surface is to have a slope, a guide line can be attached to the post according to the slope. Then a layer of crushed stone or coarse gravel with a grain size of 0/40 is filled into the pit and along the guideline with a vibrator, which can be rented from the nearest hardware store compacted. If the pitch is later heavily used, the first layer should be at least 20 cm thick.

To determine the approximate requirement for gravel or To determine gravel, simply multiply the length of the area by the width and then by 20 cm. In turn, squared timber or T-rails with a height of 5 to 10 cm are placed on the compacted gravel layer, on which along the next layer, which may be fine gravel, 0/5 grit or sand, with a straightedge is deducted. Optionally, the sides of the pit can be secured with curbs, mortar or the like prior to placing the fill and laying the flagstones. Depending on the nature of the adjacent areas, it may also make sense to install a drainage system. Incidentally, it should also be noted that the underground variant described here can of course also be used on a concrete slab can be applied in order to achieve a significantly higher base for the stone slabs very easily and relatively inexpensively receive.

Tool and material requirements when laying panels

• excavator (optional)
• shovel
• wheelbarrow
• ruler
• shaker
• corner post
• guideline
• coarse gravel/gravel
• fine gravel/grit/sand

Laying work – what needs to be considered?

Even if stone slabs do not necessarily have to be laid with parallel joints, it would be for laypeople but still recommended, especially since they are simply based on a stretched guideline when laying could. In addition, joint crosses, which ensure a constant joint width or a constant panel spacing, can be used. The joint width should depend on the size of the stone slabs. The larger a stone slab is, the wider the joint should be. It is also advisable to always start with whole slabs, as this way you can only Outside, panels can be cut to size using an angle grinder with a diamond cutting disc must.

In order to cut panels, said grinder is first guided along the underside and then along the front side. To prevent contamination from the grinding dust, the stone slab should be soaked before and after cutting. With regard to the accurate laying of slabs that are not to be fixed with mortar or placed on slab supports, it can help to check the joints of each slab to be filled with filling or jointing sand immediately after laying, as they are more stable in this way and are therefore no longer accidentally displaced during further work can. It should be noted that many experts have given up on backfilling because rainwater can run off directly through the joints.

Conclusion: Laying stone slabs - no problem for do-it-yourselfers

Laying stone slabs is a task that in itself any skilled do-it-yourselfer can easily cope with. However, you should work as conscientiously as possible when preparing the substrate, as the smallest mistakes could only be noticed when laying the tiles, but then they are very difficult to rectify let.

• For more complex cutting of hard and large slabs, it is advisable to use a cutting machine. These can be borrowed from building materials stores for a small fee. It is important that you wear gloves, hearing protection and safety goggles.
• It is important that the plates are only adjusted directly before they are inserted. This avoids cutting plates.
• Should this happen anyway and the slabs were not too expensive, you can smash them and use them as gravel for the next way. This means that no wasted disk remains unused.
• The slabs are laid similar to the plaster. After leveling the sandy surface again, lay the slabs and solidify them with a few blows of a rubber mallet.
• Small wooden wedges are placed between the individual panels to achieve an even joint thickness. After the slabs have been laid on the sandy floor, fine sand is swept into the joints and sanded away.

• For terraces it is recommended to lay the slabs in concrete. You don't need a lot of concrete for this. A thin layer covering the bottom will do.
• The panels lying on top are more stable and the edge panels do not tend to come loose as quickly.
• However, in order to guarantee that the water can drain away, the joints should not be filled with concrete but with sand.
• A later greening of the joints with short grass or moss can result in a good visual medium.

A high-pressure cleaning device is often used to care for the panels later. These can be used without hesitation. However, you should be careful not to flush out all the joints. The high-pressure device should always be handled very carefully.

Stone slabs - step by step to lay the garden path

• Choice of plates: polygonal panels look very rustic, all straight panels go well with modern design
• Slab size: The smaller the slabs, the easier it is to lay them, but the more work it takes to grout
• Selection of the curbs to match the stone slabs
• Calculation of the required quantity and order 
• Determination of a favorable storage place for the pallets with the panels
• Check panels for contamination from the transport packaging and clean if necessary. clean
• Excavate the topsoil on the garden path to the depth of the base layer (15 to 20 cm depending on the planned load).
• Install base layer (gravel-sand mixture or crushed stone).
• Compact and level the base course, making sure there is enough slope in the direction of the garden (minimum 2.5%)
• Lay curb stones according to the manufacturer's instructions
• Apply a laying bed of a few centimeters of sand (2 - 5 cm, grain size 0 - 2 mm).
• Compress the laying bed and pull straight off 
• Lay the panels according to the respective laying instructions, maintaining an even joint width (minimum 1 centimetre).
• Tap the freshly laid slabs with a rubber mallet, one at a time or after a few pieces, depending on the slabs selected
• If there are height differences when knocking, these are compensated for with sand
• When the laying is complete, the filling of the joints can be tackled
• Fixed jointing with a mortar material or jointing with unbound material (sand, quartz sand, grain size 0 – 2 mm) is possible.
• After the final cleaning, the stone slabs can still be impregnated

Although the basic procedure is always the same, you would of course have to find out exactly what the manufacturer says about laying these tiles before laying them. With every type of flagstone, there are special tricks that you can follow to make your garden path really beautiful.

Learn more about garden path - paths in the garden