Archive for category Building Construction
Lantern Light | Architectural element of Roof lighting
Posted by BenzuJK in Building Construction on March 4, 2010
Before the introduction of plastic and fibre glass as material for rooflights, the majority of rooflights to flat roofs were constructed as lantern lights or deck lights which were framed in timber or steel and covered with glass.
A lantern light is constructed with glazed vertical sides and a hipped or gable-ended glazed roof. The vertical sides of the Lantern light are used as openings for ventilation.
Lantern lights were often used to cover considerable areas, the light being formed with substantial timbers or iron and steel frames in the form of a glazed roof to provide top light to large stairwells and large internal rooms. The traditional lantern light of timber or steel requires frequent or careful maintenance if it is to remain sound and watertight.
Theory of Built-up Sections
Posted by BenzuJK in Building Construction on February 20, 2010
- A built-up beam is also known as compound beam.
- The built-up beams are used when the span, load and corresponding bending moment are of such magnitudes that rolled steel beam section becomes inadequate to provide required section modulus.
- Built-up beams are also used when rolled steel beams are inadequate for limited depth.
- In building construction, the depth of beam is limited by a space provided by the architect.
- Drawing beam of small depth do not provide required section modulus. Therefore, plates are attached to the beams.
- The strength of rolled steel beams is increased by adding plates to its flange which is one of the method forming built-in section.
- The other method is to compound a number of rolled steel sections themselves.

The built-up sections shown in figure’ A’ and ‘B’ are used for heavy loads and small spans.
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Originally posted 2009-12-25 06:14:13.
Various types of Roof trusses for various spans
Posted by BenzuJK in Building Construction on February 6, 2010
What is a Truss?
- In Architecture and Structural Engineering, a truss is a structure comprising one or more triangular units constructed with straight slender members whose ends are connected at joints referred to as nodes.
- External forces and reactions to those forces are considered to act only at the nodes and result in forces in the members which are either tensile or compressive forces.
- Moments (torsional forces) are explicitly excluded because, and only because, all the joints in a truss are treated as revolutes.
King Post Truss

King Post roof truss (spans upto8M)
- King Post Truss is a wooden truss.
- It can also be built of combination of wood and steel.
- It can be used for spans upto 8m.
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Originally posted 2009-12-28 06:32:18.
Column Bases | Design of Steel Structures
Posted by BenzuJK in Building Construction on February 5, 2010
Column bases are structural elements used in the design of steel structures to transfer the column load to the footings.
Types of Column bases:
1) Slab base
2) Gusseted base
Slab Base

- Slab bases are used where the columns have independent concrete pedestals.
- A thick steel base plate and two cleat angles connecting the flanges of the column to the base plate.
- In addition to these, web cleats are provided to connect the web of the column to the base plate.
- These web cleats guard against the possible dislocation of the column during erection.
- The ends of the column and also the base plate should be mechanized so that the column load is wholly transferred to the base plate.
- Area of base plate= (load of column)/(permissible bearing stress in concrete)
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Originally posted 2009-12-15 06:01:45.


