Installing the product

Firstly, the product is heavy – it is one of the main concerns when installing concrete and other natural stones.
The simplest way to understand the weight of the product is to calculate the volume of the product in liters (multiply the length, width and thickness of the plate in meters and convert the result into liters by multiplying it X 1000) and to multiply the results with the average material density coefficient, which is 2.1 kg/l.

For example, the weight of a plate that is 2.5 m long, 62 cm wide and 4 cm thick is about 130 kg (2.5 m x 0.62 m x 0.04 m = 0.062 m3 x 1000 = 62 l x 2.1 = 130.2 kg).

The volume of openings is calculated according to the same formula and their mass is subtracted from the mass of the worktop.

Preparing footings – worktops for kitchens do not require additionally reinforced kitchen cupboards (if we are talking about worktops with a thickness of up to 40 mm) as the weight is divided between several cupboards and does not pose a threat to the furniture.
Additional constructions and reinforcements are primarily necessary for bathroom sinks or worktops that are attached to the wall or mounted upon a cupboard which is not placed on the floor but has been attached to the wall (in such cases, the wall has to be able to withstand the weight of the worktop as well).
Reinforcements are also necessary in case of worktops with a thickness of 60 mm or more.

Cover under the worktop – a full cover, such as a plywood plate, is required under the worktop in case of thin i.e. decorative surfaces e.g. narrow window sills, which are up to 25 mm thick. The thickness of an ordinary kitchen worktop of 40 mm is strong enough for a person to stand on.

When installing – the main thing to consider is that the worktop should be carried (transported) edgewise – this way it is least affected by tensions – installation takes place in a similar way as well.

During transportation, it is important to make sure that the worktop – even if it is packaged in a wooden frame – is not put down sharply, but that it is done smoothly and softly – this principle applies both when unloading it from the car and transporting the worktop up or down the stairs.

Before installing, the worktop will be placed edgewise in front of the cupboards and then lifted edgewise onto of the cupboards (to the center or as close to the back as possible), after which the surface will be carefully lowered into a horizontal position and then gently moved into the correct position. As the worktop is heavy, it has to be slightly raised when moving it over so that the bumps on the bottom of the worktop would not damage the walls of the cupboard or base plates.

When lifting the worktop to its place, it is very important that the worktop is supported in its whole length, not only from the ends – when lifting, one of the lifters has to support the worktop by the cut-outs (stove) on both sides of the cut-out equally to other lifters (certainly not from the middle of the narrow edge of the cut-out).

Installing sinks, stoves – as a rule, worktops are 40 mm thick. With such thickness, their weight and strength ratio is most optimal. Furthermore, this thickness enables fastenings for kitchen faucets and other appliances to be installed without using additional bolts or other special solutions (with thicker worktops, there have to be hollows under the worktop for fastening the faucets and the fastenings of sinks also often do not reach sufficiently far on a thicker worktop as they are typically designed for relatively thin wooden or tin-plate worktops).

Stovetops or sinks are installed using stone glues or silicones. The most widespread method of installation is by using silicones. However, only neutral silicones may be used as acidic silicones do not attach to the surface of the stone but damage it. If it is necessary to install a sink that is glued from the bottom, stone glues (such as Penosil Premium StrongFix 707 Hybrid) have to be used. In case of large Franke sinks, the length of which exceeds 700 mm, we recommend anchoring the sink to the worktop with small bolts in addition to using glue. For that, drill (without blows) openings under the worktop that do not pass through the worktop and have a diameter of no more than 8 mm. Then anchor the bolts into these openings with hardening epoxy glues (do not use dowels as these may create tension that breaks the worktop).

The pipe-connectors, siphon and faucet for a sink are connected according to their installation manuals, but in some cases longer bolts have to be used as the walls and bottoms of concrete sinks are thicker.

Fastening the worktops – the bottoms of long worktops are relatively coarse and press against the furniture with their weight. Therefore, additional fastening with silicone or glue is not necessary – smaller plates, such as window sills, should be fixed with glue or silicone (cannot be acidic silicone, must be neutral silicone).

The joining lines of different plates are isolated with silicone mass; acrylic mass can also be used. The gap between plates has to be minimal – <1 mm. If the height of the joining line of the plate has to be brought to level, it is done with thin plastic wedges under the plates.

A sink cast into the worktop (concrete sink) increases the total weight of the worktop by 25-45 kg.
This is particularly important in bathrooms where the sink or the sink cupboard is fastened to the wall. This requires a strong wall construction and therefore ordinary plaster walls are not suitable. There have to be additional reinforcements in the wall.