While some people think that the quality of the materials used in the construction can be a reliable indicator for estimating the building’s overall strength, others think that the reputation and track record of a builder can be a better guide. A look by Nemmani Sreedhar
You have earmarked that dream house you always wanted to own. You even finalised the finances and secured credit lines to take possession of that building. But how can you be sure about the quality of the building that you are going to occupy?
While some people think that the quality of the materials used in the construction can be a reliable indicator for estimating the building’s overall strength, others think that the reputation and track record of a builder can be a better guide.
But when it comes to modern constructions, the quality of the final product could be less than the quality all its ingredients, construction material expert L.H. Rao says. Because of this, it is always advantageous to go for testing a building’s strength using latest technologies, he explains.
The easiest type of testing that can be used to ascertain the strength of a concrete roof is to load it with weights and check the degree of variation that it undergoes under that load.
Though this type of testing will give a direct measure of a structure’s ability to sustain weight, the building might sustain physical damage as a result of the excessive stress. Because of this, not many opt for this type of verification, Dr. Rao explains.
But with the recent advancements in the field of construction technologies, we do have a wider range of testing methods to opt from, he says. Because these methods can measure different parameters of a structure, that too with minimum physical damage, they are called ‘Non-destructive Testing’ (NDT) methods.
The most common and easiest method of NDT is visual inspection. A trained eye can easily find out any apparent visual aberrations in a structure. Be it a crack, a stress mark, a damp spot or an unusual touch up on a surface, when carefully observed, these apparently minute indicators can sing a song to an expert, revealing the health of a building.
The best part of the visual inspection method is that even a novice can, at least, surmise that there is some aberration in the structure. Unless a building sustains a serious damage due to a natural calamity or due to some unusual incidents, its deterioration often starts from seemingly innocuous damages and assumes monstrous proportions if these tell-tale signs are ignored.
A periodic visual inspection can reveal these defects and can help us in nipping these problems in the bud. But this type of inspection has its own draw backs. As there is no specific data available to back the damage assessment, a prospective builder can write off your observations.
Also finding an expert who can accurately estimate a building’s health can often be a herculean task.
But for those who want an accurate test that can churn out specific data regarding various aspects of a building, there are more technically ‘sound’ methods. One such method with which we can measure the strength of a wall or a concrete block is ‘Schmidt Rebound Hammer Test’. With this test we can measure the ‘hardness’ of a surface and it can also reveal the type of material used and the strength of the bonding between those material.
“The Schmidt Rebound Hammer Test is usually effective to measure the strength of a wall. Often we find that because of the usage of higher grade cement for plastering, a wall’s outer plastering is stronger than the wall itself. By scraping a small portion of plaster and using this hammer at that spot we can measure the actual strength of the wall,” Dr. Rao explains.