Saturday, November 18, 2023

Contractor

  THE CONTRACTOR

 

Table of content: 1- What is a contractor.
                                2- Contractor dos.
                                3- General contractor.

What is a contractor: contractor is an                                                                  organisation (or sometimes a person), hired by the client to carry out the work that is required for the completion of a project.
A contractor is anyone who directly employs or engages construction workers or manages construction work. Contractors include sub-contractors, any individual self-employed worker or business that carries out, manages or controls construction work. They must have the skills, knowledge, experience and, where relevant, the organisational capability to carry out the work safely and without risk to health.

Contractors and the workers under their control are most at risk of injury and ill health from construction work. Contractors therefore have an important role in planning, managing and monitoring their work to ensure any risks are controlled.

Contractor Dos:
  • make sure the client is aware of the client duties under CDM 2015 before any work starts
  • plan, manage and monitor all work carried out by themselves and their workers, taking into account the risks to anyone who might be affected by it (including members of the public) and the measures needed to protect them
  • check that all workers they employ or appoint have the skills, knowledge, training and experience to carry out the work, or are in the process of obtaining them
  • make sure that all workers under their control have a suitable, site-specific induction, unless this has already been provided by the principal contractor
  • provide appropriate  supervision, information and instructions to workers under their control
  • ensure they do not start work on site unless reasonable steps have been taken to prevent unauthorised access
  • ensure suitable welfare facilities are provided from the start for workers under their control, and maintain them throughout the work
  • coordinate their work with the work of others in the project team
  • comply with directions given by the principal designer or principal contractor
  • comply with parts of the construction phase plan (PDF) to relevant to their work

General contractor:
In the construction industry, a general contractor is the person or company responsible for overseeing a construction project. Property owners will typically hire general contractors to ensure a construction job is completed safely, on time, and according to specifications.

General contractors, often called GCs, are important for both complex commercial construction, and straightforward residential projects. More specific tasks — like replacing a roof or laying new flooring — may be outsourced to different types of subcontractors. However, a GC is likely needed for any project that requires coordinating several stages or multiple specialty contractors to complete the job. 

Read on to learn more about the role general contractors play in construction, how to determine if a GC is required for a project, and how GCs are licensed and paid.
payment is disbursed. 

In short, a general contractor manages all of the moving parts that make it possible to take a construction project from beginning to end. The GC often assumes a managerial role while subcontractors complete the required labor. 

On smaller-scale projects, the GC may complete some of the work themselves, only contracting out specialized work.

GCs are just one of many different types of contractors, but they serve a crucial role in ensuring a project gets completed and everyone involved in the construction process gets paid. 

Overseeing construction work according to contract specifications
Keeping the project on schedule
Coordinating specialty contractor timing
Inspecting construction quality and/or scheduling inspections
Making payments to specialty contractors and vendors
Collecting and tracking lien waivers
Overall, a GC’s role during construction is to make sure that everyone is working well together and reacting to challenges that could negatively affect the schedule or budget. 

In the construction industry, a general contractor is the person or company responsible for overseeing a construction project. Property owners will typically hire general contractors to ensure a construction job is completed safely, on time, and according to specifications.

General contractors, often called GCs, are important for both complex commercial construction, and straightforward residential projects. More specific tasks — like replacing a roof or laying new flooring — may be outsourced to different types of subcontractors. However, a GC is likely needed for any project that requires coordinating several stages or multiple specialty contractors to complete the job. 

Read on to learn more about the role general contractors play in construction, how to determine if a GC is required for a project, and how GCs are licensed and paid

What does a general contractor do?
A GC is responsible for seeing a construction project through from beginning to end. Essentially, a GC acts as a go-between between the property’s owner and everyone who brings the building to life, including materials suppliers, vendors, and tradespeople. 

The GC’s responsibilities depend on the delivery method used in the project. For example, with design-build projects, either the architect or the GC manages the entire project from start to finish. This means the GC may be responsible for managing both the design, and construction, of a project. 

For a design-bid-build project, a design team and GC both report to the owner under separate contracts. The design team develops the contract documents: drawings, specifications, and other exhibits. Once completed, the designs are sent out for GCs to provide a bid on the project and then see the project through to completion. 

The GC has important responsibilities before, during, and after the actual construction process that help with getting the project completed. 

Before construction
During the preconstruction phase, a GC may be responsible for some or all of the following:

Developing a construction budget
Hiring subcontractors to complete specialized tasks
Collaborating with the architect to make sure the design is realized
While all of these tasks begin before construction starts, the GC will continue to manage the budget, work with the architect, and interact with additional contractors throughout the remainder of the project as well.

During construction
While construction is taking place, the general contractor is typically responsible for:

Overseeing construction work according to contract specifications
Keeping the project on schedule
Coordinating specialty contractor timing
Inspecting construction quality and/or scheduling inspections
Making payments to specialty contractors and vendors
Collecting and tracking lien waivers
Overall, a GC’s role during construction is to make sure that everyone is working well together and reacting to challenges that could negatively affect the schedule or budget. 

After construction
Once construction work is completed, a GC still has responsibilities, including:

Collecting and tracking any lien waivers
Ensuring that specialty contractors are paid for their work
Managing issues with payments down the payment chain
Since the GC is the main point of contact between subcontractors and the building owner, the GC ensures that work is completed to specification and then payment is disbursed. 

In short, a general contractor manages all of the moving parts that make it possible to take a construction project from beginning to end. The GC often assumes a managerial role while subcontractors complete the required labor. 

On smaller-scale projects, the GC may complete some of the work themselves, only contracting out specialized work.

GCs are just one of many different types of contractors, but they serve a crucial role in ensuring a project gets completed and everyone involved in the construction process gets paid. 

GC licensing requirements
Generally, state laws require that contractors, including GCs, are licensed. Licensing has benefits for all stakeholders involved in a construction project. Here are a few ways that licensing requirements benefit various parties:

States and municipalities use licensing to regulate contractors and confirm that they follow guidelines for insurance, taxes, and safety. 
Property owners benefit from licensing as well, since they can find contractors who have established their credibility and trustworthiness. 
Contractors themselves gain advantages from being licensed, including the ability to protect their lien rights in many states. 
Working with licensed contractors is an important part of making sure that everyone involved in a construction project gets paid. 

The bidding process for general contractors
For commercial and public construction projects, the bidding process is generally the entry point for a GC on the project. The process begins when the project owner or architect shares that a project is ready for bid and makes the bid documents available to GCs. 

Additionally, the owner or architect sends out a request for proposal (RFP), request for quote or qualifications (RFQ), or an invitation to bid (ITB) package. This may be sent to select GCs, or it may be shared openly for all available GCs to bid. 

Afterward, GCs generally follow a sequence of events in an effort to win a contract for the project.

Once the bidding documents are available, GCs begin their own bidding process, subdividing the scope of work and soliciting bids from a pool of specialty contractors
The GC reviews bids from contractors and selects winning bids
Then the GC puts together a proposal to submit to the owner or architect
In some cases, the owner or architect may take additional steps, like creating a scoring system, or interviewing multiple GCs to help choose the best candidate for the project. 

Make it easier to manage construction.
Illustration showing framers assembling a wooden wall

Differentiating between construction contractors
While GCs are important for managing the overall building process, they aren’t the only contractors or managers in construction. On most job sites — especially for large-scale projects — a variety of other roles will also be required. Here are a few that you should know:

General contractor / Prime contractor: Whoever holds the main contract with the owner is considered the prime contractor. The GC can also be the prime contractor, but some project delivery methods call for non-GCs to be prime contractors.
Construction manager: A construction manager (CM) has similar responsibilities to a GC, but they are often employed directly by the owner, who tasks the CM with estimating costs, hiring a GC, or performing any other duties required to manage a project. 
Specialty contractor: The GC hires a number of specialists, known as specialty contractors, to perform specific tasks on the construction site. In a typical project, the GC is paid directly by the owner while specialty contractors are paid by the GC.
These are just a few of the key members working on a construction project, and there are many more who work for construction companies in many capacities.

A general contractor’s role in the payment process
Generally, GCs are paid directly by the property owner. That said, payment in construction can often be confusing — and payment for GCs is no exception.

GCs are an important part of the payment chain, which is the way that money moves from the property owner down to various tiers of contractors and suppliers. Poor communication and visibility can make this process slow, leading to delayed payments for everyone involved in a project.

Here are some of the problems that GCs can face in the payment process:

Visibility can be limited. A GC may only be familiar with their immediate subcontractors but not sub-subcontractors or suppliers.
Risk is inherent. A GC can face risks of non-payment if they don’t secure lien waivers. 
Payment may be contingent. A GC has to fulfill requirements to get paid as well, further complicating the flow of funds down the payment chain. 
Fortunately, there are ways to speed up payment in construction and make sure that everyone is paid on time for their work. Typically, increasing the visibility of subcontractors and sub-subcontractors, streamlining paperwork, and maintaining open lines of communication all go a long way toward resolving payment delays.

Saturday, February 25, 2023

TYPES OF BEAMS

 Different Types of Beams


A Beam is a structural element that primarily resist loads applied laterally to the beam's axis. It's is mode of deflection is primarily by bending. The loads applied to the beam result in reaction forces at the beam's support points. The total effect of all the forces acting on the beam is to produce the shear forces and bending moment within the beam, that in turn induce internal stresses, strains and deflections of the beam. Beams are characterized by their manner of support, profile(shape of cross section), length and material.

Different types of beams are used in the construction of buildings and structures. These are horizontal structural elements that withstand vertical loads, shear forces, and bending moments. Beams transfer loads that imposed along their length to their endpoints such as walls, columns, foundations, etc.


What are the types of support conditions in beams?

1. Roller
2. Pinned
3. Fixed

What are the types of beams based on support conditions?

1. Simply supported beam
2. Fixed beam
3. Cantilever beam
4. Continuous beam


Types of Beams in Constructions

There are different types of beams which are classified based on the following conditions


  • Based on Support Conditions
  • Based on Construction Materials
  • Based on Cross-Section Shapes
  • Based on Geometry
  • Based on Equilibrium Condition
  • Based on Method of Construction


Based on Support Conditions


1. Simply Supported Beam

It is one of the simplest structural elements that both ends rest on supports but is free to rotate. It contains pinned support at one end and a roller support at the other end. Based on the assigned load, it sustains shearing and bending.


2. Fixed Beam

It is supported at both ends and fixed to resist rotation. It is also called a built-in beam. The fixed ends produce moments other than the reactions.


3. Cantilever Beam

If a beam is fixed at one end and set to be free at the other end, it is termed as a cantilever beam. The beam distributes the load back to the support where it is forced against a moment and shear stress. Cantilever beams allow the creation of a bay window, balconies, and some bridges.


4. Continuous Beam

A continuous beam has more than two supports distributed along its entire length.


Based on Construction Materials


5. Reinforced Concrete Beams 

It is constructed from concrete and reinforcement as shown in Fig. 5. Sometimes reinforced concrete beam is concealed in reinforced concrete slabs and it is called hidden beam or concealed beam


6. Steel Beams 

It is constructed from steels and used in several applications.


7. Timber beams

The timber beam is constructed from timber and used in the past. However, The application of such a beam in the construction industry is significantly declined now.


8. Composite Beams 

Composite beams are constructed from two or more different types of materials, such as steel and concrete. Fig. 8 shows Different valid cross-sections for the composite beam.



Based on Cross-Section Shapes


Several cross-sectional shapes of beams are available and used in different parts of structures. These beams can be constructed from reinforced concrete, steel, or composite materials:


Reinforced concrete cross sectional shapes include:


9. Rectangular beam 

This type of beam is widely used in the construction of reinforced concrete buildings and other structures.


10. T-section beam

This type of beam is mostly constructed monolithically with a reinforced concrete slab. Sometimes, Isolated T-beam is built to increase the compression strength of concrete.

Added to that, inverted T-beam can also be constructed according to the requirements of loading imposed.



11. L-section beam 

This type of beam is constructed monolithically with a reinforced concrete slab at the perimeter of the structure, as illustrated in Fig


Steel cross sectional shapes include:

There are various steel beam cross-sectional shapes. Each cross-sectional shape offer superior advantages in a given condition compare with other shapes.

Square, rectangular, circular, I-shaped, T-shaped, H-shaped, C-shaped, and tubular are examples of beam cross-sectional shapes constructed from steel.

Steel beam cross sectional shapes


Based on Geometry


12. Straight beam

Beam with a straight profile and the majority of beams in structures are straight beams.

straight beam


13. Curved beam

Beam with curved profile, such as in the case of circular buildings.



14. Tapered beam

Beam with tapered cross section.



5. Based on Equilibrium Condition


15. Statically Determinate Beam

For a statically determinate beam, equilibrium conditions alone can be used to solve reactions. The number of unknown reactions is equal to the number of equations.



16. Statically indeterminate beam

For a statically indeterminate beam, equilibrium conditions are not enough to solve reactions. So, the analysis of this type of beam is more complicated than that of statically determinate beams.



Based on Method of Construction


17. Cast In-situ Concrete Beam 

This type of beam is constructed on the project site. So, forms are initially fixed, then fresh concrete is poured and allowed to hardened. Then, loads would be imposed.


18. Precast Concrete Beam

This type of beam is manufactured in factories. So, the construction condition is more controllable compare with on-site construction. Consequently, the quality of the concrete of the beam would be greater.

Various cross-sectional shapes can be manufactures such as T- beam, Double T-beam, Inverted T-beam, and many more.



19. Prestressed Concrete Beam

The pre-stressed concrete beam is constructed by stressing strands before applying loads on the beam. Pre-tensioned concrete beam and post-tensioned concrete beams are variations of pre-stressed concrete beam.


20. Deep Beam 

A deep beam has considerable depth, as shown in Fig. 21, and its clear span to depth ratio is less than four, as per ACI Code. A substantial load is carried to the supports by a compression force combining the load and the reaction. Consequently, the strain distribution is no longer considered linear, as in the case of conventional beams.



21. Girder

Beams that take heavy loads, generally steel sections are used.