The following cuts, thicknesses, weights and barbecuing times are meant to be guidelines rather than hard and fast rules. Cooking times are affected by such factors as altitude, wind, outside temperature and how well you like your meat cooked.
Two rules of thumb; cook steaks, fish fillets, boneless chicken pieces and vegetables using the direct method for the time given on the chart, turning once, halfway through cooking. Cook roasts, whole poultry, bone in poultry pieces, whole fish and other thicker cuts using the indirect method.
Cooking times for beef and lamb are for MEDIUM unless otherwise notes.
Let roasts and larger cuts of meat rest for 10 to 15 minutes before carving, keeping in mind that the internal temperature will continue to rise 3 to 6°C while it is resting.
To calculate the cooking times for any roasts (without a cavity, i.e poultry), measure the thickness and calculate 1 minute per millimeter. For example if the roast is 90mm thick, cook it for 90 minutes.
For the full PDF of the all the barbecuing guides you can download in HERE.