Steel Types and Grades

Steel Types and Grades

Steel offers exceptional qualities in terms of mechanical resistance. Of the most commonly used materials in construction, it demonstrates the greatest resistance for the lightest section, both in tension and compression. This opens the door for architects to a wide choice of technical and aesthetic solutions. 

The main steel grades that we are using in our structures are S235, S275 and S355 for structural members.

Steel Product Types

The steel products can be classified into two main categories, as shown in the below figure

1. Hot Rolled Profiles

Hot rolled long products (often referred to as ‘sections’ or ‘profiles’) are generally used for the main frame members (columns, beams, bracings).

Sections undergo various transformations through cutting, welding, bending etc., in order to obtain very different shapes and improved performance.

2. Cold Formed Long Products

Cold formed long products, formed from thin sheet steel, are generally used as secondary members for cladding (rails) and roofs (purlins)

3. Flat Products
In metal building construction, the use of flat products is mainly for the following purposes:
• Steel decking for floors
• Roofs
• Cladding
For each of these purposes, thin sheet steel is used, frequently formed into profiled sheets

Essential components of steel buildings

Essential components of steel buildings

A pre-engineered steel building is a modern technology where the complete designing is done at the factory and the building components are brought to the site in a completely knock down condition and then fixed/jointed at the site and raised with the help of cranes.
In this article we will highlight the three types of components used to build modern steel structures

1. Primary Framing

Primary framing is comprised of fabricated columns and rafters; referred to as frame lines or main frames when bolted together. These are the heavy members in the superstructure that bear the major weight and applied loads. 

These components are the distinguishable elements that people can see, and know without a doubt, that they are looking at a metal building. At Tekmetsan we use generally hot rolled sections for columns and rafters. 

Without the complete primary frame, the building would not stand up to vertical or lateral loads over time. The following items, bolted or welded together, form the superstructure:

• Columns: The vertical supports. Columns can come shaped as tubes or with a cross-sectional shape of a capital H, I, L or U.

• Beams: The horizontal supports that rest atop the columns. Usually I or H-shaped with flanges perpendicular to the “web” or main plate.

• Rafters: Also beams, these horizontal members support the roof assembly.

• Trusses and Lattice Girders: Alternative support for the roof or upper floors, comprised of a latticework of bracing metal between top and bottom chords. While the chords bear compression and tension loads, the bracing resists shear forces.

• Girders: Horizontal beams that support floors.

2. Secondary Framing

Once the backbone of your framing has been determined, the next step is to plan the secondary framing. 

Providing the stabilizing members that prevent the main frame from twisting out of shape, secondary components can also contribute to the structural support and provide the means to attach wall, roof and interior elements. The secondary framing usually transfers loads to the main frame.

• Girts and purlins: Girts tend to be Z-shaped, providing support for wall panels while increasing the strength and stability of the primary framing. Purlins serve the same purpose, but are utilized in roof applications.

• Wall and Roof Braces: Bars, cables rods or strips that resist shearing and contribute more lateral stability.

• Eave Struts: The transition piece between the wall girts and roof purlins along the eave.

• Headers and Jambs: The framework for openings such as doors, windows and bays.

3. Fasteners

The primary and secondary framing components needed to complete your structure will be manufactured in a steel fabrication facility to ensure the highest levels of quality and consistency. 

Once these pieces arrive on your site, it is time to assemble them with the approved fasteners:

• Bolts (anchor bolts, U-bolts, and so on)
• Construction screws
• Inserts
• Weld studs
• Threaded studs

Building Envelope

Typically comprised of pre-coated, single-skin metal panels; however, insulated metal panels are becoming more commonplace. However, just as common, the materials used to enclose a metal building structure can vary from masonry to glass, wood siding to innovative architectural panels, and beyond. Chances are the brick façade you see on your favourite retail store is hiding a metal building beneath. In certain applications, the metal panels add structural integrity to the building system as a whole, and why the term metal building systems is commonly used. 

Single-skin panels and the metal components of insulated panels are cold-formed, just like the secondary framing.

Sheet steel runs through a progressive series of rollers that shapes the flat material into a specific cross-sectional profile that is strong and durable. After cutting to length, appropriately bundled and crated, the finished product is ready for delivery.

While an economical option, the through-fastened metal panel remains a long-lasting, attractive and versatile product. Architectural metal panels offer concealed fastener options, with enough variety to likely satisfy all aesthetic demands. 

What is a pre-engineered steel building ?

What is a pre-engineered steel building ?

There is not one but many definition of pre-engineered steel building

• A cost-efficient building system alternative to conventional construction
• A steel building designed for the most efficient use of raw materials
• A structural system generally including steel framing, roofing, and wall cladding
• A structure built on site using prefabricated components
• A simplified, streamlined building system designed for quick construction

Check out the below video prepared by American Metal Building Builder Association.

The versatility of steel prefab buildings makes them a popular building solution for commercial enterprises, industrial structures, and even personal use buildings.

Designing a Pre-engineered Steel Building

Tekmetsan pre-engineered steel buildings are not standard designs ordered from a catalog. Each of our prefab building is designed, engineered, and fabricated for the specific project, based on the customer’s needs.

Based on the customer-supplied details, computer-aided design software creates working plans and detailed drawings.

Current local building codes, equipment loads, and other detailed criteria are fed into advanced steel engineering programs.

Every order includes an anchor bolt plan and a full set of assembly plans.

 

Fabricating a Pre-engineered Steel Building

Drawings detailing the manufacturing of every piece of the framing arrive at the manufacturing plant.

Each individual component of the framing is precision cut, shaped, welded, drilled, painted, and marked per the exacting specifications in the drawings.

Tekmetsan supplies prefab buildings with a single-source shipment of the entire steel framing system. 
All the framing pieces and accessories ship together.
 Everything arrives at your job site on an agreed schedule.

Erecting Prefab Buildings

Typically, a steel prefabricated building erects in significantly shorter time of more labour-intensive construction methods.

Detailed drawings shows the exact location of every piece of the framing puzzle.  It is just a matter of installing the pre-marked pieces in the locations indicated. All structural members bolt together easily.

Conclusion

Pre-engineered prefab buildings are the modern solution for low rise buildings on practicality, price, and performance. With years of experiences, Tekmetsan offers design and fabrication of pre-engineered buildings.

ISO 12944 – Protective Paint Systems

ISO 12944 – Protective Paint Systems

Corrosion must be considered early in the design of steel structures. If left unprotected in corrosive environments, steel structures are liable to corrosion that can be both costly and put lives in danger.

One way to control corrosion is to use paints and coatings. ISO 12944 is the internationally recognised standard that provides instruction and guidance to those working with steel structure design, including planners, painters, inspectors, maintenance, and manufacturers of coatings.

How a steel structure is designed has a real bearing on the ability to protect it against corrosion. Poorly designed structures may have corrosion traps which are difficult to protect and from which corrosion can spread rapidly.

The basic steel structure design criteria that may be exposed to corrosive environments include keeping the design simple and minimising surfaces that may be exposed to corrosive pressures.

Designers should incorporate design elements to prevent water being trapped and where foreign matter may combine to increase the potential for corrosion. Design features that might be considered include inclined surfaces, drainage systems, and chamfered edges.

• The shape of the structure
• The use of the structure
• Structural elements such as method of joining
• Environmental factors

In many instances, steelwork will be in a warm dry interior where it will not corrode, and the structural stability of the building will not be threatened during its design life (generally taken as 50 years). In such conditions (classified as C1) no corrosion coating is required. Examples include steelwork inside dry buildings with neutral atmospheres such as multi-storey office buildings, shops, schools, hotels, residential buildings, airport terminals, and hospitals, etc.

However, when steelwork is exposed to moisture, corrosion will occur at a rate depending on the severity of the environment. In such cases, a coating system appropriate to the environment category should be provided. Note that some buildings may contain areas where different environment conditions apply e.g. hospitals would normally be C1, but may contain kitchens and laundry areas that would normally be C3. Some types of buildings, such as car parks may fall into any of the above categories or combinations of them depending upon their location, design and construction.

Experienced technical sales of Tekmetsan will help you in determining what kind of corrosion class your structure falls. After identifying the corrosion class, our experts will offer you the appropriate coating solution for your budget.

Tekmetsan has very deep knowledge in both high and low corrosion environments and delivered various steel structures with various coating options. Get in contact with us today and let’s discuss your steel building.

Steel Stairs

Steel Stairs

Steel staircases offer several benefits over other traditional materials such as timber and concrete. Other than its obvious durability and longevity, steel is a cost-effective, practical and versatile modern staircase construction material:

• It delivers a modern aesthetic

• It is significantly stronger than timber construction

• It is very flexible to meet almost any design challenges

• It enables fast and secure erection.

A striking staircase design is the focal point of your walkthrough and should blend seamlessly with the rest of your building. Not only should the design impact and complement your structure but it should also be practical.

Tekmetsan has broad experience in designing and fabricating commercial and industrial staircases.

Industrial Staircases

Modular, permanent, code-compliant, industrial staircases (cage, cat ladders) designed to meet the access requirements of industrial applications.

Designed in modular units with a choice of standard stairs or alternating tread stairs. Each unit is assembled and then installed by stacking and bolting together at the base plates for easy alignment. No welding is required for assembly or installation.

• Roof access
• Tank access
• Long-term construction site stairs
• Equipment access
• Work platforms

Commercial Staircases

Tekmetsan fabricates bolted stair systems consisting of pre-fabricated landing, stringer, tread, and rail components that are easily customized to meet specific project requirements.

We provide dedicated, in-house resources for each step of your commercial steel stair project
• Estimating
• Project management
• Modeling and detailing
• Material delivery scheduling and phasing
• Installation drawings and support

Applications
• Hotels
• Apartment buildings
• Office and mixed-use
• Mid- and high-rise buildings
• Health Institutions
• Parking garages
• Multi-level storage facilities
• Student housing

Design & Modeling

Our in-house design team provides all necessary documentation for a successful staircase delivery.
• All projects include modeling and BIM coordination
• .ifc files for structural steel coordination are available
• Complete General Arrangement Set for review and approval

After the order confirmation we provide:
• ISO views
• Section views
• Plan views
• Dimensions
• Connection details