This spreadsheet was developed so that you can figure an approximation
of how much FlexKrete you will need based on the volume of the hole you are filling. Be warned, it is usually very
difficult to gauge the AVERAGE DEPTH accurately, and even a 1/4" variance makes a
big difference in the volume of FlexKrete required.
It is usually simpler and more exact to guess the size of the hole in gallons, then divide
by 4 to estimate the gallons of FlexKrete you will need.
How it works
These estimates are based on the volume of our sand
required to fill a void, then extrapolates the volume of FlexKrete you will need based
on the ratio of sand you prefer.
For flatwork, most contractors prefer using about 50lbs of sand per gallon of
FlexKrete - (3.5 parts sand to one part FlexKrete). We do not recommend using
more than 3.8 parts sand to one part FlexKrete unless it is a light duty
For vertical and overhead repairs most applications require
2 to 2.5 parts sand. You will actually get some additional volume from the
1.5 parts fumed silica which is not calculated in this spreadsheet.
If you are having difficulty estimating the amount of FlexKrete you will need,
please contact us for help. FLEXCALC for WEB.xls
Insert Measurement of Voided Area and Ratio of Sand