Hello im not very good at diy so please answer in simple terms . I live in a high rise block of flats which has a closed balcony it used to be open balcony .my problem is is that There is a hole in the balcony ceiling it will be concrete the hole is were the old pipe work used to be but I need to fill it some how as I can see up ann through To the persons above me balcony and I think they have dogs amd the smell that comes through is terrible any help amd asvice how to solve this will be appreciated.