Rough gas usage on young annual weeds is 1x 5kg bottle per 1000m² (weeds up to 100mm high)
Rough gas usage on established annual weeds is 1x 5kg bottle per 500m² (weeds up to 200mm high)
Rough gas usage on established perennial weeds is 1 x 5kg bottle per 250m² (Weeds up to 200mm high)
It is difficult to establish the gas usage for weeds outside this specification.
Consider using mechanical methods instead.
Consioder removing the cause of the plants access to soil on hard surfaces.
Use biological controls on organic surfaces such as mulching, dense planting of a desirable species, change treatment timings to fall within the above specification.
Cost of 5kg refill GASLITE cylinder from FLOGAS is about £35.00
In comparison The Easy+ kit uses a 10 - 12kg cylinder on the trolley and the lance as above. A refill for this is considerably cheaper at about £42 which roughly halves to cost of the gas.
Notes. Prior to heat weed control solutions it is recommended all sites are cleared of detritus.