How to Check the Strength of the Existing Building?

How to Check Strength of Existing Building

The strength of the building is a crucial thing to evaluate because it provides a comfortable space to live in. But how do you assess the strength of a building? Let’s find out.

The evaluation of concrete strength on-site presents a significant problem, whether determining the quality of new construction or evaluating the condition of existing infrastructure. To prevent further harm to a structure already in trouble, owners and maintenance managers typically favour non-destructive and non-intrusive solutions. But how do you check the strength of the existing building?

Suppose you choose non-destructive methods in building projects that result in less intervention, shorter downtimes, and financial savings. All sides concur, however, that a crucial factor is solid strength.

To evaluate the integrity of the structural state, the client frequently employs a structural engineer or team of engineers.

For structural engineers, this duty is a significant challenge since it necessitates a thorough review and investigation to determine the source of the flaws and the best way to fix each one. It is to ensure the structure is both structurally and physically sound.

A team of civil and structural engineers typically performs an existing building’s structural examination. These recommendations should be considered while evaluating the building’s structural condition.

Is it Important to Check the Strength of the Building?

The strength of the building is the basic fundamental part of construction by the engineer. It ensures fit to support and trust to live in the building. It gives the surety of breaking, collapsing deformation, etc. It will help you not cause severe injuries or damage to yourself or the building and loss of life.

Methods to Check the Strength of the Building

Let’s see the steps to ensure the strength of the building:

Site Background

It is crucial to understand the site’s past when evaluating the current building; it is the first stage. From this point, we may start to learn more about the structure that is being evaluated. Before we begin the evaluation, there are a few things we need to know, including the building’s age or construction date, its change in occupancy, and any rehabilitation work that has been done. When conducting such an investigation, the immediate area is also crucial.

A Site Visit and Inspection in Person

A visual site inspection requires a preliminary evaluation of the building and ascertaining the potential severity of the damages and faults. The Engineers should visit the site to perform a visual evaluation and obtain information about the building’s condition. Physical flaws, including fractures, corrosion on the reinforcement, obvious beam deflections, and other visible flaws, should be photographed and documented.

The following are typical inspection findings that can find in concrete during site inspections and observations:

  • Cold joints
  • Concrete honeycomb
  • Slab soffits and hairline cracks in the slab
  • Exposed steel reinforcement because of insufficient concrete cover
  • Column misalignment because of bad formwork during casting

A Wall’s Thickness

The builder must specify the wall thickness in the layout agreements. Verify the accuracy of the construction site. If the walls are hollow or made of plywood, you can tell by tapping them with your knuckles. Builders widely use plywood walls to reinforce the building. However, if termites are not adequately managed, they might harm such structures.

Paint Quality

During your site visit, look for erratic fractures in the plaster of the walls. Even a little crack might indicate the quality of the wall paint. If the walls aren’t properly cured, cracks may form and get worse over time. While high-quality paint can increase the durability and aesthetic appeal of the walls, incorrect drying might hasten the walls’ premature deterioration.

Concrete Core Compression Test

It’s frequently believed that extracting concrete samples and measuring their compressive strength is the most economical and dependable option.

Many standards and recommendations view this as the sole accepted technique for determining the strength of concrete. In this instance, if the concrete core removes from an already-existing building. This method is the most accurate way to calculate compressive strength. The process is rather quick.

Rebound Hammer to Strengthen Concrete

The Rebound Hammer measures the rebound of a spring-driven hammer mass following its contact with concrete. It operates on the rebound principle. Engineers and inspectors can utilise more recent iterations of the test to assist with a wider range of material qualities thanks to commercialisation.

The rebound hammer is the most popular non-destructive test for concrete since it is straightforward and inexpensive. It is widely employed, if unintentionally, as a technique to evaluate the durability of concrete.

Ultrasonic Pulse Speed

An efficient technique for checking the quality of concrete materials and spotting damage to structural elements is ultrasonic pulse velocity (UPV).

Traditionally, UPV techniques have been used to check the quality of materials, primarily homogenous materials like metals and welded connections. The test got generally recognised for evaluating concrete materials due to recent advancements in transducer technology.

The idea behind the technique is to measure how long acoustic waves pass through a medium and then relate that information to the material’s density and elastic characteristics. Ultrasonic wave travel time reveals the internal state of the test region. Some scientists have attempted to establish a connection between wave speed and strength.

Collecting Structural Samples for Lab Testing

Concrete samples or specimens should be gathered on the spot and sent to the lab for further examination. It is done to determine the current structural members’ density and compressive strength and validate the necessary information and data.

Studying the effectiveness, resilience, and strength of the material utilised in an existing construction shall be considered throughout this procedure. Concrete should undergo laboratory tests to evaluate its physical, mechanical, and chemical qualities. The region under study should be covered by the physical samples or concrete specimens taken from the structural elements in the depiction. It is advisable to do site testing, which may involve

Removing a concrete sample to examine the chloride content and check for corrosion on the steel reinforcement.

  • Concrete cores were drilled into structural members to be examined physically and mechanically to ascertain each specimen’s true densities and compressive strengths.
  • Use a digital cover metre to conduct a concrete cover inquiry to ascertain if the rebar is adequately covered and protected.
  • To ascertain the quality and rate of steel corrosion, do the resistivity and ultrasonic tests, respectively.
  • Calculate the concrete’s shattered surfaces’ depth.

Quality of Sanitary Wares & Bathroom Fixtures

Examining the general shape of sanitary fixtures and accessories, such as washbasins, toilets, bidets, and face cleansers, is the best way to judge their quality.

High-quality fittings should be simple and comfortable to use. If it makes a raspy sound when you lightly touch it, there could be cracks. In addition, you may check to verify if the mounting surface is flat and smooth.

Check the faucets’ ability to be replaced quickly, the sort of faucets used, and the water flow. Find out if it’s simple to find replacement components for bathroom fixtures. You should also look at the bathroom tiles and insist on choosing non-skid ones to prevent accidents.

Testing Results Evaluation and Interpretation

The next duty of the engineer participating in the evaluation of the structural integrity of the building is to synthesise all the results and conclusions based on the physical and mechanical characteristics of concrete as a consequence of the data and laboratory tests mentioned above.

You should list and outline these facts before drawing a judgement on the general safety of the building. At this point, the concrete’s quality is known, the area’s accurate concrete coverage has been determined, and perhaps most significantly, the concrete’s actual compressive strength has been determined.

Repair Work

As recommended by the engineer, structural strengthening may be necessary. Planning remedial work is needed to ensure the building is structurally sound and safe. It is important to evaluate the type of repair required and the process for carrying it out. According to the engineer’s findings and recommendations, structural improvement, jacketing, and retrofitting may be suggested.


Now, the query on how to check the strength of the existing building gave an idea to consider and follow the steps. If structural strength is necessary for the damaged structural members, the structural engineer will either suggest it or make the final decision. The glaring flaws that are physically visible should be fixed if necessary.

Therefore, in the event of low concrete compressive strength findings, it should consider a structural redesign and building design utilising the real design data results acquired from the laboratory testing. In this context, structural retrofitting and strengthening are essential to increase the strength of the existing structures.


What steps must be taken to ensure excellent construction?

A building’s quality construction aims to create a structure and guarantees that construction projects are done effectively and affordably.

What test can be used to study the uniformity of concrete?

The rebound hammer method is used to study the uniformity of concrete.

What determines the strength of the building?

The quality of the material, water ratio, cement, temperature, humidity, etc., will determine the strength of the building.

How can we check the strength of the building?

A client can hire a structural engineer who can test the strength of the building very keenly.