There are cases when insulation should not immediately be applied. For example, if a faulty surface is created by the casting, a crack could develop over time, after application of insulation. In this case, the faulty surface should be treated with special concrete material to provide a good infrastructure, and the insulation should be applied on top of that.
Creation of a Complicated System of Channels
A water reservoir situated far away from the roof, and far from the water sources. the photograph illustrated the complicated system of concrete channels that we built from the roof down to the reservoir, and from the reservoir to the various water sources. (This is an alternative to the outdated and less halachically recommended system of using a vacuum to draw the water through a pipe.)
