What is the cause for fly ash Brick wall cracks ?(See attached photo)

Krishna22

Apprentice
Dear Sir,

Please go through the photograph of plaster crack on fly ash brick New wall not old. Any material issue fly ash bricks compressive strength -8.7 N/Sqmm & water absorption -16% .

IMG_20210309_122028.jpgIMG_20210309_125504.jpgIMG_20210309_122050.jpg
 

Dnyan Deshmukh

Staff member
It is not much clear from the photo weather there is failure in surface of bricks for bonding or the lack of curing along with higher thickness of plaster.

When the thickness of plaster is increased, Mason normally do have tendency to do plaster in a single layer for full thickness by dry shaking of cement on wall surface. when thickness is increased there is a chance of settlement and de-bonding of plaster from wall surface. not curing the plaster makes it further more worse by de-bonding it on larger area.

De-bonding can also be accounted for not doing pre-wetting of wall surface specifically on walls next to street where lot of dust is emitted and settled on wall surface from long time, if not cleaned by washing wall surface (pre-wetting), this can cause a de-bonding issue.

You need to do further more close inspection to identify the root cause of the same.
 

Mehboob

Senior Member
May be the quality of cement and sand were not good,I mean silt content of sand was more I suppose,and try to investigate that the wall has experienced any sudden impact or hammering before
 

Krishna22

Apprentice
Thank you.. Sir
One particular area is problem. Vibration is any cause for de-bonding. Because nearest area compacted by 12 MT roller. Horizontal cracks are there.
1.Any chemical reaction is there?
2.Project other area work on same source of bricks and sand but No cracks on other brick wall.
3.Particular that LT panel room 2nos wall that type of problem arise.
 

Mehboob

Senior Member
Thank you.. Sir
One particular area is problem. Vibration is any cause for de-bonding. Because nearest area compacted by 12 MT roller. Horizontal cracks are there.
1.Any chemical reaction is there?
2.Project other area work on same source of bricks and sand but No cracks on other brick wall.
3.Particular that LT panel room 2nos wall that type of problem arise.
Could you please tell me the age of plaster.