The first take-off attempt towards the South was abandoned because the pilot was uncertain whether the aircraft would become airborne in the distance available. He noted that the windsock indicated calm conditions, and after completing another engine run, elected to take-off towards the North. However, the windsock was sheltered from the prevailing wind and did not indicate the five to seven knot tailwind existing for the initial part of the takeoff. Full power was applied before the brakes were released, however acceleration appeared to be uneven, reducing as the wheels passed through soft areas on the strip. The aircraft struck a fence shortly after lift-off, and touched down in a nose-high attitude. It then bounced several times, struck a mound of sand and debris, and overturned. The investigation established that with the tailwind and soft wet surface conditions existing at the time there was insufficient runway length available. The pilot recognised the slow acceleration of the aircraft, but delayed his decision to abort the takeoff attempt.