How to best fix a crack in concrete balcony corner?

Question

So I was recently pondering a problem with a crack in a corner of a balcony made of concrete as shown below in the picture. I am not a builder (rather an amateur handyman) but would like to educate myself of how this might be best approached if a solution would ever be required. The previous owners indicated they had purchased the home back in 2006 and this crack was already there. How might this have happened and for what reasons one could speculate ? I am not an expert but from the photo I cannot ascertain if an attempt was ever made at a repair, and the owners seemd to not have been bothered by it during their stay ...

The crack gets larger in size from the bottom to the top of the ledge that is about 60cm high, and the widest crack gap is about 9-12mm. It is static, ie not getting larger day by day (contrary to what some might have thought). The crack appears uniform and identical in size from both sides of the balcony. The balcony itsel is rather small and a huge load in that corner would probably not have been the cause of the break ...

I was told that one of the best ways to fix this permanently, would be by employing somekind of stainless steel anchors with epoxy to effectively "stitch" the crack together, and then to finish it with an appropriate concrete filler etc.

What are the experiences and thoughts on the best way to do this fix and how much should one expect to pay for professionals to do such work ? What commercial systems are best suited for this permanent mend ? The house is situated in a European country...

thanks in advance for your suggestions...

cheers, MM

Answer 1

The taper of the gap (which you've described as "increasing in size from the bottom to the top") is not concerning if it's staying put there, as it settled to 20 years ago or whatever at the time of construction.

Presumably it was poured in place and the balcony deflected a bit under its own weight when the formwork was removed. If it's solidly attached to the floor of the balcony so it's not in danger of falling off, I would not worry about it.

If the gap is increasing over time, you should be concerned, and you should consult a licensed structural engineer about it.

I would not describe that as a crack - it clearly was never attached to the wall - it was merely poured adjacent to it. So rather than something solid cracking into two pieces, you have two separate pieces which started out touching (evidently) and moved slightly to form a gap between them. Nothing actually cracked, and there's no evidence that any attempt was made to make the joint structural at time of construction.