Cracking in precast concrete exterior wall tilt slabs

Cracking in precast concrete exterior wall tilt slabs

Any cracks in precast concrete walls can allow water to seep in and corrode the reinforcing steel.  If the reinforcing steel is allowed to corrode, it can expand and further damage the concrete.  The ultimate failure of the wall is known as spalling where lumps of concrete break off and the reinforcing is exposed.  Spalling can be treated but in the worst case, the slab might need to be replaced so it is recommended that building owners take action and fill cracks and prevent the worst-case scenario from occurring.  By diligently filling all cracks that have the potential to let water in, the building owner can be confident the concrete exterior walls will last the life of the building.  

There is no common standard that says that a crack of a certain size should be filled because other factors need to be taken into consideration such as how wet the wall gets, how quickly it dries out and what the wind pressure is on each face. There is also no way of testing whether or not water is getting in.  However, logically, the bigger the crack, the greater the risk.  Also, building owners can have confidence that modern methods now available for filling cracks are reliable and considering the value of the slab over the life of the building, relatively low cost.   

If an owner isn't sure, they can consult an engineer or other expert, but any expert is likely to err on the side of caution and advise to fill the cracks.  Apart from the cost, the only reason an owner might not want to fill any cracks is because of the look.  A wall with filled cracks can detract from the look of the building.  But if that wall is going to be painted, apart from the cost, there is no reason why an owner shouldn't just go ahead and have the cracks filled.  

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The Plan Heaven team.

Disclaimer. Plan Heaven is not qualified in law and any comments made on this website are only the opinion of Plan Heaven and should not be regarded as legal advice. Our comments are merely providing some thoughts on how the legislation might be interpreted and how we go about attempting to meet its requirements. You should not rely on this information in isolation and do you own homework and at all times if you wish to be sure of your position relating to legal matters you should seek advice from a suitably qualified lawyer.