Hot Dip Galvanizing – Characteristics and Costs
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Hot dip galvanizing

Zincatura a Caldo

Hot dip galvanizing is an anticorrosive treatment of steel that is applied by immersing the products, after a series of pre-treatments, in a bath of molten zinc.
The differences and characteristics
Unlike paints, where we are talking about a polymer film, in the case of hot dip galvanizing we are talking about a metal, namely zinc. Already this first difference highlights extremely different performances: the painting can be easily damaged already in the simple and simple loading and unloading operations or on site handling, while for zinc, due to its very metallic nature, it has an enormously superior resistance to shocks. and abrasions, moreover the hot galvanizing protects both the external and internal surfaces.
Another fundamental difference between galvanizing and painting is the adherence of the protective layer. It is one of the main positive characteristics of hot dip galvanizing, with the exception of galvanizing, all anticorrosive treatments consist of a layer that acts as a barrier between the steel and atmospheric corrosive agents, this is not enough if for any reason, a abrasion or a simple scratch to allow corrosive agents to creep between the protective layer and the steel forming rust.
This process does not take place for hot galvanizing, since it is not a simple covering film, in fact during the immersion in the molten zinc a real iron-zinc alloy is formed which, as such, is tenaciously clinging to the steel and is removable only with a robust mechanical action or with strongly acid solutions, for this reason even if it were to be able to scratch the zinc layer for its entire thickness, atmospheric corrosive agents could not proceed further penetrating under the zinc layer being, as said, alloyed with steel.

Another consideration to make is that with aging paints, in addition to being subjected to the aggression of UV rays, become permeable to water and high aggressive substances, zinc instead maintains its characteristics absolutely unchanged throughout its cycle of life.

 Zincatura a Caldo
The life cycle of hot dip galvanizing
The zinc layer, if exposed directly to pollutants and atmospheric agents, progressively transforms into oxidized compounds, of which a part participates in the protective action and a part is removed by the mechanical action of the rains.
This phenomenon is repeated continuously for many years until the zinc is completely consumed; however, it must be said that, when this has occurred, the steel structures will still be perfectly intact as they have never been attacked by the corrosion that begins only when the steel actually remains uncovered. In fact, zinc performs its function even if reduced to a very thin layer.
To understand how long it takes the zinc layer to wear out, you need to know its thickness and corrosion rate. The thickness of zinc is generally a function of the thickness of the steel and can vary, for structural steels greater than 5-6 millimeters, between 85 and 150 microns and beyond.
The corrosion rate can vary between 0.1 and 2 microns per year in the most common use scenarios while, in extreme conditions, it can even go beyond this limit.
On the basis of these data, excluding extreme or rare usage scenarios, it can be said that the duration of protection offered by hot dip galvanizing can vary from a minimum of 40 years to well over a century.
What can be hot dip galvanized?
Anything that is made of steel can be hot dip galvanized. It is possible to galvanize large and small structures: Pillars, coatings, trusses, pipes, emergency stairs, fences, gratings, lattices, poles, street furniture, ski lifts, scaffolding, tanks, bolts, etc., the list would be endless because, like said, everything that is steel can be galvanized, the main limit is set by the size.
Zincatura a Caldo
Hot-dip galvanizing price: Is the cost of galvanizing excessive?
Even if most of the steel structures that could also be galvanized and are not, the reason is certainly not the cost of galvanizing, since it remains in the same order of magnitude as painting, as regards the immediate but is of great importance. long shorter in relation to the duration and therefore to the absence of maintenance over time.
The colors of the galvanizing … is it possible to obtain other colors besides the classic gray?
The answer of course is no! But it is possible to apply paints of any color, finish and brilliance to the galvanizing. The result of this operation, which certainly has a higher cost than galvanizing alone, is to obtain an even higher protection, and therefore a duration. At this point, the two anticorrosive treatments develop such a synergistic effect that the duration of the protection far exceeds the sum of the durations of the two treatments, if considered individually. The useful life of the product is further increased and always without the need for maintenance.
Colori Zincatura a Caldo
Is it worth hot-dip galvanizing?
Hot-dip galvanizing protects steel structures for a time that often exceeds the useful life cycle of the structures, is eco-sustainable and preserving from corrosion keeps the design characteristics unaltered, collaborating in the general safety of a work. It also has a low initial cost and comparable to other anticorrosive systems and since it does not require maintenance for decades, it greatly reduces the cost of a work over time.
Suspended reticular structure
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Struttura Reticolare Sospesa

Reticular Suspended

…. nearing completion the construction work of the building complex called “Decomposition” of the Chianese Group, in via Parmenide in Salerno,

for which ICOMET Costruzioni Metalliche S.r.l. has created and installed the reticular connection structure between the two staircases, placed at a height of about 50ml.

Struttura Reticolare SospesaStruttura Reticolare Sospesa

 

The building complex, once completed, will house in its 12 floors, houses, commercial premises and offices, with panoramic terraces, hanging gardens and breathtaking views of the Gulf of Salerno.

Once again Icomet does not deny its nature as … … … builder of ideas !!!

Safety stairs
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THE SECURITY STAIRS

Emergency stairs or safety stairs are often the only safe way out in the event of fire, or in the event of calamitous events such as earthquakes. In some cases, however, in order to be considered suitable also as “emergency routes”, they must have particular safety features.

Ordinary stairs, in fact, as well as being an indispensable means of communication inside the building, if not compartmentalized, also constitute an element of the building that easily lends itself to a rapid spread of smoke, heat and flames to the upper floors, in quantum, they behave like chimneys in which a “draft” is determined due to the difference in height between the base and the top and this inevitably entails that the staircase is invaded by smoke and quickly not accessible.

Although the Italian legislation does not explicitly speak of fire escape stairs (emergency stairs), with this term in common language we usually refer to three types of stairs, each of which can be used as an escape route in case of need:

1. the external safety stairs;

2. the protected stairs;

3. smoke-proof stairs.

The relative definitions are contained in the Ministerial Decree of 30 November 1983.

Scale di sicurezza

Security stairs

The construction of fire escape stairs is mandatory:

  • in public buildings or buildings open to the public such as schools, offices, museums, shopping centers and hospitals;
  • in hotels and collective accommodation;
  • in residential buildings with a fire protection height of at least 12 meters, where it is not possible to approach the fire brigade ladders with at least one window or balcony per floor (e.g. skyscrapers and large multi-storey buildings).

The fire height is the maximum height measured from the lower level of the highest opening of the top floor living space to the level of the lowest external floor: a fire height of 12 meters therefore corresponds to a four-storey building.

The references, by way and exodus stairs, are contained in the Ministerial Decree of 3 August 2015.

In this article we focus on external safety stairs, and in this case those with steel frame and walkways in grated panels.

The safety stairs are stairs that are totally external to the building and must comply with certain characteristics:

1 meter high parapet able to withstand the strong stresses that can derive from a rapid and disordered flow of people;

    • Handrail placed retractable protruding no more than 8 cm;
    • Ramp width equal to at least 2 modules, or 1.2 meters;
    • Rectangular steps with a tread not less than 30 cm and a rise not exceeding 17 cm;
    • Straight ramps and with no less than 3 steps and no more than 15;
    • Absence of protrusions or recesses for at least 2 meters from the walking surface;
    • Landings must have at least the same width as the ramp;
    • Trapezoidal steps are allowed, provided that the tread is at least 30 cm measured at 40 cm from the central upright or from the internal parapet;
  • The doors leading to the stairs must be equipped with a self-closing device, must open in the direction of the exit, and their opening must not in any way obstruct the flow of people going up or down;
  • For buildings with more than two floors above ground, the width of the staircase must be dimensioned by adding the crowds of the two consecutive floors with greater crowding.Below is an example of a fire escape or safety ladder with cage:

Scale di Sicurezza

One of our achievements Click here

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