Kemax s.r.o.  
We have been bringing you products for more than 20 years made of sheet metal of the highest quality at excellent prices, for the satisfaction of you and your clients.
Kemax s.r.o.  
We produce plain sheets, trapezoidal profiles and corrugated sheets in various thicknesses, galvanized, lacquered and in almost unlimited length.
Kemax s.r.o.  
We are a long-standing Slovak producer of high quality sheet metal products.

   Assembly recommendations



Trapezoidal boards must be manipulated in a vertical position.
The boards must not be placed on the side, holding them by the reinforced part.

Due to safe handling and thermal expansion, the boards recommended by the manufacturer are up to a maximum length of 6000 mm.
Dimensions longer than 6000 mm are not covered by the warranty for expansion faults of trapezoidal profiles and defects caused by incorrect handling of trapezoidal profiles.


We cut the sloping edges basically on the ground and on a hard surface. The tools listed below are required for cutting and trimming. If it is necessary to cut these areas on the roof or in the roof space, it is necessary to remove sawdust from the sheet metal with a soft whisk after finishing the work, which would otherwise start to oxidize, thus leaving rusty stains on the sheet.
During assembly, it is absolutely necessary to treat all cutting and cutting edges, including cutting edges, which were created during the production process of trapezoidal sheets.



If the collection of trapezoidal sheets by the customer is not followed by immediate assembly, it is necessary to store the sheets in closed, dry and well-ventilated areas, where there are no large temperature fluctuations. Outdoor storage is also possible for short periods, while the trapezoidal sheet metal must be covered with an air-permeable tarpaulin. In both cases, the pallets with the sheet metal must be underlain with sloping pads at a sufficient height above the ground to ensure sufficient ventilation.
If trapezoidal sheets are stored for more than two weeks, the individual trapezoidal boards must be underlain with wooden expansion strips. Storage for more than two months is considered a breach of warranty. In such a case, any claim regarding damage to the surface treatment of trapezoidal sheets will not be accepted.
The rules for the storage of trapezoidal sheets apply equally to all other products supplied by KEMAX s.r.o.


We assemble trapezoidal sheets T18, T29, T50 and KEMAX products with common plumbing tools. For cutting and cutting trapezoids, we use manual sheet metal shears or electric perforating shears or a straight saw with a steel cutting blade.
DO NOT use an angle grinder to cut!
When using an angle grinder, the trapezoidal sheets are damaged and degraded by overheating the steel core and consequent damage to the protective surface treatment. The damage caused in this way is excluded from the complaint.

Preparation before assembly

We will make sure that the slope of the roof really meets the requirement of at least 5 °. Before starting work, check the right angles between the gable and the drip edge. If the roof is not rectangular, we must level it with gable edging. We proceed similarly when cladding objects. After we have set the right angles on the roof surface, it is advisable to stretch the cord along the gutter edge to the plane according to which we will stick during the actual assembly of the trapezoids. Trapezoidal boards must always be placed perpendicular to the gutter line.



We start the assembly of trapezoids by assembling the roofing foil, but this is not a condition. For the perfect functioning of the roof, it is necessary to use high-quality high-diffusion foils due to the high condensation of water vapor characteristic of sheet metal roofing. We mount the foil directly on the rafters from the gutter horizontally to the ridge.
We carry out the assembly itself exactly according to the instructions provided with the foil. We will secure the foil with the same type of roof batten as the batten itself. The minimum gap between the foil and the roofing must be 5 cm. We design the roof battens or the wooden roof structure itself according to the type of trapezoidal profile used, of course with regard to the drawing documentation and the static assessment.
We never design the thickness and tip of the trapezoidal profile as well as the span of individual roofing materials without the necessary drawing documentation or static report. The last slats must be mounted at least 5 cm from the ridge. Trapezoidal profiles can be assembled in various ways, from left to right and vice versa by stacking individual sheets of sheet metal. We still stick to the level of the gutter during installation, which we have marked with a string.
For the assembly of trapezoids, we use screws measuring 4.8 x 35 intended for mounting sheet metal into the roof batten, or trapezoidal nails designed for mounting in the upper wave of the trapezoid, and screws measuring 4.8 x 19 intended for connecting sheet metal to metal sheet. We install the roofing with a system of 6 screws up to 1 m2, while the screw must be mounted in the bottom wave, basically in every other wave in the horizontal direction. The number of screws depends on the roof structure and the individual axial distance of the roofing materials or trusses. The actual distribution and assembly of the screws depends on the type of construction, the profile used, the axial distance of the trusses and the thickness of the material.
Plumbing construction elements, such as gable edging, gutter edging and the like are supplied by the manufacturer in standard dimensions. However, when reconstructing older buildings, it is more appropriate to produce them individually exactly to measure. All plumbing components are anchored in two ways: with a screw or a plumbing nail.
We assemble the comb in two ways, either on the ridge lath using a ventilating ridge strip, which at the same time achieves perfect straightness of the ridge while the ridge is attached to the top, or by connecting the sheet metal to the sheet metal, which in practice means that we attach the ridge with a short screw directly to the trapezoidal module.
For installation chimney cladding, or installation roof windows and hatches, it is better invite an expert, to do this during , given that these works are in a way specific and it could happen that unprofessional installation of these elements will be reflected in the quality of roof functionality in the future.