My 40 x 4 ft pre-cast concrete balcony (2nd floor) has hairline cracks on the top and wider cracks on the bottom side (it's 45 years old). It is exposed to rain (no cover) so water is working through the cracks. A masonry company suggested pouring a 3/4" top layer ($2,700, cha ching, and I don't like the weight sagging the balcony) as a fix.
TOH has a video on repairing vertical cracks in concrete basements using an injected epoxy glue & epoxy crack filler kit. This is OK for the basement, but would be unsightly for a balcony.
My thought is use a conventional crack filler, and sand down the crack filler, and use waterproofing substance. I also don't want to have the hairline cracks opening up again (epoxy glue would fix it).
Any ideas ? Thanks for any comments.