Expert: Veto Varma - 10/9/2007

Question
dear Sir,
at one of our projects , we are using hollow concrete blocks for walls,and later on covered with plaster.
For the same, we have used mesh reinforcement at the interface of blocks with cast in situ concrete framed structures.Now as we want to go ahead with painting works, we have observed periodic horizontal cracks in the plaster.
Kindly advise the cause and remedy

Answer
Hi Amjad,

Horizontal cracks may be due to either because of blocks sliding or only plaster cracks. If is certain that it is because of concrete block that smells trouble. I suggest to use local engineer and get it inspected thoroughly before proceeding further.

These cracks may be because of many reasons e.g. insufficient interlocking or spacing of reinforcement or excessive loading or it may be simply plaster cracks. If the cracks are widening then it is possible because of concrete blocks.

There are remedies available for it depending on the cause of cracking. e.g. for non structural reasons epoxy may be an option and for minor structural reasons grouting may also be resorted for, but for serious structural problem I will suggest again to Use engineer on site.

Regards
Veto