Please does anyone know how to calculate the volume of concrete produced from a bag of quickset. The sort that's ready mixed and you just add water. I'm putting a fence up and have calculated that I need around 35 litres of concrete per post. Problem is that I don't know what volume you get from...
Is there some way I can just treat it and then skim over. I'd rather not have such a major job of taking the ceiling down. This means clearing a load of stuff out of the loft and pulling up all the boards and insulation.