asliarun

Dear forum members,

I have a basic question. What should I look for to determine the quality of construction of a building?

For example, I have had bad experience with cement block walls. In my experience, they are more porus and weaker compared to red clay brick walls, and in two personal examples, rain water has seeped in directly through cement brick walls causing seepage.

In this example, is it necessarily true that clay bricks are superior to cement bricks or at least to uncured cement bricks? Why are so many builders using cement bricks nowadays?

Besides this example, what other qualities, raw materials etc. should I look for to determine how strong and solid a building exterior, frame, and interior construction is?

Another example: Amanora is supposedly using a new construction technique called "mivan", where as per my understanding, entire walls etc. are built on-site by pouring concrete into moulds. Is this technique superior in terms of strength?

Thank you in advance for your replies! I tried searching the net for info on this but could not make too much progress. Hence, I am relying on your answers to understand these basics.

aditi sharma

As per what I had read about 'mivan' tech is that it makes construction rapid and hence usefull for mass housing projects. This is without compromising on quality but I guess quality may depend on other factors too, ie execution of technology.

lazybone007

Hmmm. Are the days of mixing ret (sand) with cement over?

asliarun

Thanks. More than stuff like mivan, I'm looking for basic information, like whether clay bricks are better than cement bricks, whether buildings on stilts are unsafe, what should be good thickness of walls, how to determine if wiring is good or not. I'm just looking for some layman answers, not civil engg. level stuff.

I have a decent understanding of what decent internal fitments like bathroom fixtures or flooring, but I know surprisingly little about the really important stuff, which is the building construction itself. I would really appreciate if anyone can shed some light on this.

Thanks!

birendra

Arun,

There are various stage in construction. To me most important one is while the RCC construction is happening. Because that forms the base(mould/trunk) of complete building.

For a layman like us it is very tough to understand the quality from naked eye but following will help give comfort feel.

• Understanding the concrete mixing process. Are they using RMC? Are they using water dispenser. How are they mixing various items for concrete. Look at who has certified the mixture.
• All builders do core tests to determine strength of concrete like M-20,M-30 etc(depending on load in building). You can ask the concrete strength they need to meet. Ask for core test results(it shd be from a designated lab) and analyse the trend……is it more then what is required………is it stable or there is fluctuation
• Look at the way shuttering is done. Can you see holes or are they packed
• Loose shuttering results in honey combing(patches in concrete)
• Availability of water and do they do enough/adequate curing
• 2 walls shd join at 90 degrees. If you see it is not the case then there is quality problem
• As far as bricks are concerned regular,fly ash, blocks all are ok as long as there compressive strength is enough. You need to look at test report
• After concrete you need to look at quality of plaster in walls and ceilings. It shd be in one plane. You will notice that many times it is not the case
• Quality of material used is important. For example for electrical wires look at the brand. Finolex,Polycab is good. For switches ABB,Legrand are good, window sections Jindal/Bharukha are good. Look at the company of tiles and quality of granite used. For sanitaryware Kohler,Hindware,parryware are good. There are other good brands as well but I have just given few examples
• Wall thickness varies.; These days I see external wall 150mm and internal 115 mm. In some places it is little more thick
• Identifying quality of finishing item is not very difficult you can see them from eye. Like tile fitting(look at gaps between two tiles)
• You must check for water proofing in bathrooms

These are my few cents.Others pls feel free to add/modify.

Regards,
Birendra.

iphadke

Birendra... I just stumpled upon this post. Thanks! It is very well thought out and at the end all my questions were answered.

Cheers,
Neel

realacres

Here is some info about the same which you may find useful about quality testing methods.

1.) NDT:-

Here a Spring hammer is used to check the strength of RCC etc. The process is simple & works on the Newtons principle "To each & every action, there is equal & opposite reaction".

The hammer is banged against the required column. If the hammer bounces back with great force to large distance, it indicates good quality. Hence, more the distance, better the quality.
If the hammer hardly comes back, it indicates... hopeless quality.

2.) Ultrasonic techniques:-

Here ultra sonic waves are transmitted & it's velocity, depth etc. is recorded in the machine. The result is displayed on the screen. Is one of the most accurate method.

3.) Core Cut Technique:-

A core is cut of few mm with the help of the requisite machine from the RCC column of the structure to be inspected. These look like small balls with few mm in diameter. 3 such cores are collected & sent to the concrete testing lab.
The average value is taken & results declared thereafter. This too has good accuracy in testing the strength & also calculates the weight/pressure the column can withstand.
You can either take the core (if you have the apparatus) & submit it to the lab (Few years ago, they used to charge some Rs.35/core i.e. Rs.105/result)or you can call the engineers to do the needful. However, site visit charges are added in such case.

Some may advise to check the QC audit of the builder. However, since builders can manipulate the report, it's best to perform the above tests & not to rely on builders' report.

The point anon raised that after 5 slabs, the builder may change the quality was indeed important. In such case, one can do the following:-

1.) Carry out the tests for plinth , G+1 level & finally the floor you are interested in & the top floor. Verify if the results are same right from bottom to top. If not, you know what it means.

2.) In case of under-construction apartments (which I recommend to avoid), you can send the concrete samples to the lab. However, in such case you will have to continuously monitor it. It will only result in wastage of time & money.

The following are the agencies in Pune who carry out the construction quality tests:-

1.) Durocrete-CQRA; is one of the oldest & amongst the best in the country. Is located at Vitthalwadi, Sinhagad Rd. & Shivajinagar.
Visit for more:-

http://www.cqra.com/Enquiry.html

2.) COEP, Shivajinagar also provides this service.

Personally, I recommend Durocrete-CQRA.

At the end of the day, when one spends lacs to crores for purchasing a house, few thousand rupees spent on QA/QC services can well give you complete peace of mind.

puser

How to gauge quality by just observation around the site? All these techniques need some technical background and may be some experiments

razer

Most builders will also tell you that they have done those exact same tests and have relevant certificates to prove that their construction quality matches what is required.

The only way is to have the certification bodies, and labs declare results. Best of luck with that, because these labs live off builders and their work.

I'm sure Durocrete has done a fair number of these tests with builders, would they be so kind as to share data?

Oh! And I haven't tried taking a core sample from a construction site. But I'd recommend you wear a helmet and other protective gear, and have a getaway vehicle ready and waiting for you, before you attempt taking samples.

asliarun

Thanks for your informative replies, Birendra and realacres!