This will depend on the porosity of the timber. To calculate the approximate coverage for 3 coats, allow 1 litre for 3 square metres.
Apply by brush or roller. Do not apply in temperatures below 16°C or above 30°C conditions. Allow 3-4 hours between coats. Drying time of 1st coat is 4-6 hours, subsequent coats 3-4 hours in 20°C conditions with average humidity. Minimum of 3 coats. In areas of constant UV exposure, 4 coats are recommended.