difference between 43 grade and 53 grade cement

[Bangalore-Mysore]

Hi
Thank you for sharing your experience.

Please anybody let me know which is the best for platering work? OPC 43 grade or PPC?
somebody told me that OPC gives smoother finish compared to OPC 43. Is it correct?
Which is free from craks or less cracks?

Thanks

[jult]

use premixed plaster. it will be good.

[amarbs]

@jult, Can you please elaborate on where this is available? Any websites?

[m3_07]

use premixed plaster. it will be good.

Pre-mix plaster is as doubtful in the quality as the RMC (ready mix concrete). Our testing methods are not so effective in order to ensure that the quality sold is as per the standards. More over, it is expensive.

[jult]

Ramco cements web site

[pavuluru]

Hi All,
We have used 53 grade for plastering external walls. We didn't know that it shouldn't be used. But, curing was really proper. It has been one month the walls have been plastered. We are able to see hairline calls on the external walls. Some of these cracks are running vertical and horizontal. Please suggest what should we do now. Should we put any white cement or any kind of putty before painting.

[jult]

silt content n the sand available in Bangalore is more than acceptable limit. So it is common in all building such cracks. grading of sand not be done at site mix as it is very lengthy process as well as lot of wastage of sand will be there. So most of the people go for shortcut to save money( but really word it is not like that).
As plastering is not structural member we compromise quality there by covering with costly paint. when aging of building happens it affects building functionality.

[sunil4050]

Hello,

The same case here with our building. The contractor used 53 grade cement for plastering without informing us whereas in agreement he had mentioned 43 grade cement. We are seeing lot of hairline cracks. He says that he can fix it by filling it up before paint job. I am not sure what to do if the cracks will appear months after paint job is done. He says that the building materials do not support the current weather conditions and there is effect due to global warming. There are few houses being built around our house where i do not see such cracks after plastering. Looks like the global warming is having effect on my building alone. Can any one suggest me what has to be done on the cracks?

[zahid]

Use 53 grade OPC (Ordinary Portland Cement) only for concrete work and do not use it for anything else, since the heat of hydration is too much, as a result of which you have to cure it extensively. Else it would result in cracks. That said, you could use 43 grade for concrete work as well.

For masonry work and plastering, use 43 grade (OR) PPC, since the heat of hydration is less and the setting time is more. This will avoid cracks.

In the longer run (say, after couple of months), both 53 grade and 43 grade will attain same strength. So, don't worry too much about this aspect.

[sunil4050]

Thanks Zahid.... whats worrying me is the usage of filter sand for plastering. The contractor has used it without informing me. Now he says there was no issue with sand quality. I can see hairline cracks throughout exterior part of the building. Few in internal walls too. Can't believe that the contractor boasts of quality while justifying his billing but has used sad tricks to build the house. Now he plas to fill the crack and paint it. I did check up with couple of other painters and they say its better to paint it now and wait for 1-2 years to let the crack reappear. Do the crack filling then and paint.