What are Pre-Engineered Buildings (PEBs)?

Pre-engineered buildings (PEBs) are metal buildings whose individual components are pre-designed and manufactured to satisfy a wide range of structural and aesthetic design requirements. All the elements and components are designed, fabricated, and constructed exclusively for the project.

Pre-Engineered Buildings (PEBs)
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PEB concept is mainly used in the construction of industrial buildings, commercial buildings, metro stations, etc.

This article takes through the various features, construction stages, and benefits of PEBs in the construction industry.

Features of Pre-Engineered Building (PEB) Construction

In PEB construction, all the building components, like columns, beams, roof elements, and support systems are uniquely designed and fabricated at the factory and bought to the site and assembled. A building is categorized as a pre-engineered building for the following reasons:

• PEBs employ a pre-set method for connecting and welding the individual components ( standard connections are used)
• Optimized design, detailing, and fabrication for lightweight, economical, and fast construction.

Pre-engineered buildings are also called pre-engineered metal buildings (PEMB) or simply engineered metal buildings (EMB). 

Components of Pre-Engineered Building System (PEBs)

The main components of a PEB system are:

1. Primary members
2. Secondary members
3. Metal skin
4. Other Features

1. Primary members

The primary members of pre-engineered buildings are the main frame, columns,  and rafters. 

• Main Frame: This forms the skeleton of the building. It is the main structure that provides overall strength to the building. It is rigid steel. The frame comprises tapered columns and rafters.
• Columns & Rafters: The main frame is composed of tapered columns and rafters. Built-up sections or hot-rolled sections can be used as columns and rafters. In the case of built-up sections, three hot rolled plates of equal thickness or varying thickness are welded together to form an I-section. High-grade steel as per ASTM A572M. 

Built-up Sections for Columns and Rafters for PEB Construction

Some of the hot-rolled sections used as columns for PEB construction are:

• I-section 10025 S355 JR (Minimum Yield Strength is 345 N/mm²)
• Square Tube ASTM A 500 Grade B (Minimum Yield Strength is 317 N/mm²)
• Channel EN 10025 S355 JR (Minimum Yield Strength is 345 N/mm²)
• Angle ASTM A572M Grade 345 (Minimum Yield Strength is 345 N/mm²

Hot Rolled Sections for PEB Construction

The built-up section compared to hot roll profiles can be tapered such that the member strongly adheres to the stress concentrations in the building. Built-up sections give the choice of the flexibility of different thicknesses adding a more economical advantage to PEB construction.

2. Secondary Members

Secondary structural components of a PEB building are the units that give support to the roof in addition to the walls. They include purlins, grits, bracings, and eave struts.

Purlins, girt, and eave struts: They are secondary cold-formed members used to support the roof system. Usually, Z-shape is provided for purlins and girts, and for eave struts, C-shape sections are employed.

3. PEB Skin

The overall skin for the PEB building is provided as roof sheets and wall panels. The roof sheets used are normally galvanized profile sheets that can be painted for better anti-corrosion properties. The PEB building walls and floors are insulated first before installing roofing sheets. 

4. Other Features

PEBs are usually equipped with substructural systems like mezzanine floors, crane systems, canopies, fascia, and interior partitions. 

Stages of Pre-Engineered Building Construction

The basic steps involved in the construction of pre-engineered building construction are:

1. Design and Engineering
2. Manufacture
3. Construction and Assembly

1. Design and Engineering

Pre-engineered buildings are designed based on the function and needs of the project. The design procedures are configured differently for each project. By following the standard regulations and building code, a particular project can come up with different design options in terms of sections, type of wall panel, insulation material, etc. The design is chosen with respect to the project.

PEB construction design may or may not involve an architect. But a local builder can come up with design requirements.

2. Manufacture

The units and components involved in the PEB construction are manufactured in the facility with accurate precision. 

3. Assembly of PEB

All the components are transported safely to the construction site for assembly. The columns are connected to the foundation, then the process continues. Most of the connections in pre-engineered building systems are bolted connections.

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