Different interlocking brick manufacturers have varying recommendations, but generally speaking, a crushed stone (gravel) base must be laid first. Using the right type (size and mixture) of stone will allow forproper compaction. This layer may be three to six inches thick. On top of this goes a one- to two-inch bed of sand, and the brick goes on top of that. More sand is spread on top of the bricks and swept into the joints. Compaction (usually with a plate vibrator) can take place a few times during the installation. Cold weather, and frost in the ground, can result in settlement of soil that has been dug up, it should not cause settlement in the brick, sand or stone, as long as the materials are dry and are compacted properly. If soil is dug up and replaced while it is frozen, this can cause problems, though. It is also more difficult to dig up frozen soil, whether or not it is replaced. Wet weather can make it more difficult to deal with the sand bed as well. As long as the driveway slopes away from the home, there should be no need to put anything at the joint where the driveway meets the house.