Does anyone else find that the expected m2 coverage stated on the back of grout bags is a little optimistic? A 10kg bag of BAL superflex wide joint claims it will cover 32 m2 based on a 300x300x9mm tile with a 3mm joint. I did a 28m floor this week with 400x400x10mm tiles and used 16/17kg!!!!! Not much silt in the bottom of the washing bucket at the end so, not much waste. I would love to know how they work these figures out.

i use bal grout, and i know what you mean, i just estimate a 10kg bag will do 12 to 15 m2..

i use bal superflex grout myself and never have any problems the grey one is great because it dries very light but a 10 kg will only do around 20m its a bit more pricey than others and doesnt cover as much but if you trust it its worth paying that bit extra

I just half what it says on the back! Just random numbers plucked out of thin air!