Due to the revisions of the common parameters on the market, SERIUS has improved the surface boxes in many parts. In order to fulfill the high demands on quality on the part of the fabricators and users, we always set our focus on Made in Germany.

Important to SERIUS is above all the onsite controlling of all quality guidelines and regulations. So if necessary, we can immediately take influence on the production. And by now, SERIUS already created 15 new working places in Germany due to the decision to produce in Germany.

The currently valid regulations that are the basis for the applied surface boxes derive in some extent from the thirties of the last century. As surface boxes were a relatively simple component, years-long, they hardly were in the focus of the inventors. Consequently, the forms as well as the applied materials are on a level that doesn’t stay abreast in all areas with the technical progress. First improvements were the introduction of the height-adjustability and the plastic base body.

High costs that are produced due to deficient products or materials concern the companies that maintain roads and utility nets. Only the damages that are produced due to the increasingly growing heavy goods vehicle traffic and the hence ensuing lane grooves, where in most of the cases also surface boxes are situated, generate enormous costs even without laying a new road surface.
Frost heave or clacking noises are still a burden for the users of the roads, the companies that maintain the roads and the residents. All these problems are easily avoidable if the manufacturing and the right choice of the products meet the purpose.

And even if repairs are necessary, on the one hand, it should be at a low cost and on the other hand, presenting an even more important aspect, also sustainably successful. But one thing is certain that mistakes that are done during a road construction can only be cleared with a high financial effort.

Further problems result from mud and corrosion. Consequently the surface boxes are difficult to open and a water closure or water supply for the fire service is impossible. Thus the cover has to be opened forcefully and then replaced.

The question is not whether to take non-adjustable or height-adjustable surface boxes. The decisive factor is the purpose. If the surface box is used for a cycle way, a sidewalk or a less used area, on correct assembly a non-adjustable surface box will serve the purpose. But if the surface box is exposed to heavy burden, in road works areas, on uncertain final heights and especially when the blinding layer is mounted after months or even after years, a height-adjustable surface box is needed. Height-adjustable surface boxes present the benefit that on repairs and later mounting of the blinding layer, the base course always remains unaffected, and consequently secondary damages are avoided. An important aspect should be mentioned regarding works contracts: using height-adjustable surface boxes, height differences between the surface box and the road are absolutely inacceptable and a reason for rejection.

The initial application of plastic surface boxes unavoidably presented a few problems. However nowadays, most of the plastic surface boxes do not present any problems at all on the assembly or regarding the technical requirements. Most of the plastic surface boxes are even superior to the mechanic and chemical requirements. The temperature resistance often worries the one or the other user, but in normal cases the doubts are unnecessary. Nowadays a surface box made of plastic easily allows an assembly with a gas flame on a heat temperature of over 240°C guaranteeing a homogenous fixing with the layer. All in all, it is to say that everything that is realizable with gray cast iron is also possible with plastic material and even better.

  • Plastic has a lower weight – thus easier to process, “one-man assembly”, low transport costs
  • Plastic is maintenance-free – no lubricants needed, no stuck cover, no corrosion, weatherproof
  • Plastic is soft – no clacking noises, homogenous fixing with the bitumen layer
  • Plastic is impact-proof – no breakage

Using plastic surface boxes on constructing a new road already avoids this problem. The experience showed that when gray cast iron is used, additional means like elastic rings, plastic rings or other soft materials do not sustainably work, and a complete replacement of the surface box is unavoidable in the long run.

Frost heaves are expensive consequences of an incorrect choice of material, incorrect assembly or a too low assembly temperature. The problem with frost heaves is that even if the repairs are carried out accurately a weak point always remains. If a surface box has to be lifted during repairs, the base course is automatically loosened. A subsequent sealing of the base course is not possible, and on a short term, due to the volume of traffic, the surface box will be compressed again. This damage pattern is mostly seen on roads, it is unusual on sidewalks or cycle ways.

The only possibility to control these problems is the use of height-adjustable surface boxes. On the one hand, these surface boxes tolerate a certain usage when lane grooves are developed. On the other hand, on repairs – provided that they were correctly assembled – only the upper part of the surface box has to be lifted and replaced, and the base course and the sealing remain unaffected. If then additionally a plastic surface box was used, the repair should sustainably last, when the surface box and the bitumen, requiring a minimum temperature of 180°C, had been correctly preheated.

Many users principally install concrete, gray cast iron or plastic supporting plates. It is the rule and makes the assembly easy. As the costs are relatively low only a few users think about the necessity, the benefit or even about a possible damage.

SERIUS recommends to work without a supporting plate in case an accurate sealing and a stable subgrade is given.

This is actually a problem that should not exist. Using surface boxes that do not meet the DIN norm or belittlingly only “follow” the DIN norm, in order to save a few cents, or due to the employee’s affinity for a particular manufacturer or provider, it’s not a surprise that a fireman once more has to break the cover of a surface box in need of water for the fire-fighting. And as no replacement cover is available the complete surface box must be replaced.

In order to handle this problem, only DIN surface boxes should be applied, no matter whether plastic or gray cast iron is used. The DIN norm exactly determines the binding dimensions in order to avoid this problem.

There are two possible reasons why a cover is stuck, road mud or corrosion. The road mud problem can be easily cleared with the help of a perfectly fitting cover. Unlike the corrosion problem, the binding bitumen layer doesn’t seem to be much good as a rust prevention, so we have to deal with this problem.

But one thing is for sure, a perfectly adapted and fixed cover is half the battle. However, huge surface boxes need a yearly maintenance. In any case, plastic surface boxes obviously present far fewer problems since corrosion occurs on one side only, and “sinter” between base body and cover doesn’t occur at all.

Height-adjustable surface boxes that had been mounted in the base course long time before the blinding layer was applied, show between upper and bottom part a conglomeration of road salt, dust, split, building materials, etc.. After a time, this leads to sinter, and then it is difficult or even impossible to open the surface box. A typical result of this problem is a forcibly damaged upper part of the surface box.

What happened? The construction worker tries to lift the upper part of the surface box with the help of a clay pick. The surface box is sintered and not movable. Then the worker applies force in order to get the surface box free. At a certain point the pressure is too much and the upper part breaks. In these cases there are no differences between plastic or gray cast iron. Gray cast iron is at a disadvantage since its resistance to impact is considerably inferior compared to plastic material.

SERIUS, the only manufacturer who acts upon sinter development, created against this problem a ring provided with a thread that avoids the intrusion of solids between surface box and upper and bottom part. SERIUS applied a patent for this system.

Two assembly situations are given, first, a new construction or reconstruction of a road, second, repairs or a new installation on an existing road. Until now, on both assembly situations two construction workers were necessary in order to install the surface boxes correctly. Of course, resourceful workers created auxiliary measures in order to do the installation alone, using broken yard sticks, cut slats, stones, etc.. But a correct position of the surface box was never given. It always needed two workers. One had to hold the upper part of the surface box on the required height and the other worker underlaid the surface box with the hot bitumen mixture. That was fine as long as the person holding the surface box remained unharmed or did not suffer burns on the fingers in spite of wearing gloves.

SERIUS recognized this problem and thanks to the possibility of a permanent fixing of the required assembly height the problem was solved at a stroke. The surface box is practically infinitely height-adjustable and can only be moved with intentional pressure or lift. A one-man assembly is easily possible without any auxiliary measures saving costs considerably. A welcome side effect is that the surface box keeps the preselected direction in each position (e.g. water in flow direction or gas in direction to the pavement or curbstone). Furthermore, the height of SERIUS surface boxes can be modified without difficulties several times and the fixing remains unaffected.

The assembly quality depends not least on the assembly temperature, no matter if the surface box is made of plastic material or gray cast iron. One thing is for sure, if the bitumen temperature is too low the assembly results imperfectly. Modern plastic surface boxes tolerate an assembly temperature of 240°C. On an assembly temperature of approx. 180°C a dense homogenous fixing between the plastic surface box and the concrete should be achievable that way that an intrusion of water and consequently frost heave is nearly impossible. A gray cast iron surface box rarely achieves a homogenous fixing with the concrete layer. Although an increased temperature is irrelevant for a gray cast iron surface box, it wouldn’t improve the fixing with the bitumen.

Plastic is as recyclable as gray cast iron. If it is impossible to reprocess the applied plastic due to the adhesion of extrinsic materials, the plastic’s residues of the surface boxes are still a demanded energy carrier. Gray cast iron with hardly soluble extrinsic adhesions is due to economy reasons not recyclable in Middle Europe. In general and unfortunately, these residues are shipped under high efforts of transport to Third World Countries beyond any further control regarding the further processing of the material. Touching the subject of transport efforts, depending on the dimension and model of the respective surface boxes, a truck loading plastic surface boxes carries about three times more compared to same make of gray cast iron.

A height-adjustable surface box DIN 4055 made of gray cast iron weighs approx. 45 kg. The same surface box made of plastic weighs approx. 16 kg. There are no doubts which of the two is easier to handle. Less weight means less risk of accident. And even if something happens severe injuries are considerably more infrequent. The risk of burns caused by hot bitumen tends to zero thanks to the fixing possibility offered by the SERIUS innovative height-adjustability. Considering the high impact resistance of plastic, less weight also means that the risk of broken and consequently useless surface boxes is significantly low.

The costs for underground working and road construction products are primarily determined by the price of raw material. Due to the minor quantity of plastic material, the price increases of the raw material are moderate. This implicates for the user a price guarantee already in the project phase.

Of course, innovation and quality might mean more expenses on a minimal leverage. But this insignificant higher price gives the user the security to be technically up-to-date, and as it is the case with SERIUS, the products are manufactured in Germany with the required quality assurance and possible onsite controlling.