Before starting, we experimented with the digger by scooping up loads of snow and dumping them on the ground. Using the same technique that we used for the ice/snow core samples we checked the density and condition of the material we had to use.
As it turned out, the snow in the area was very dense. It was also icy, bordering on slushy in places. This means that it would pack well and, when piled up compress into an even denser mix. This was not quite what we'd hoped for, as we had anticipated more powdery snow. However, the area had been subjected to some (relatively) warm weather and prolonged sunshine.
In addition to the snow tests, we also used the digger to clear the surrounding area.
This would give us a good view of the frames and underside of the tile and permit easy access.
Coming next... the first load of snow is placed on the tile!