Small gravity retaining walls are relatively simple structures that can be built with unskilled labor and locally available materials.
Cold weather concreting presents some special problems, especially if temperatures are below freezing. Cold weather concreting practices should: prevent damage caused by freezing at early ages; protect concrete until it reaches necessary strength levels; allow concrete to cool gradually when protection is removed so that a rapid temperature drop doesn't cause it to crack.
The waterstop is a long, thin barrier against water leakage. Like the links in a chain, every part of its length must do the job. There are many different waterstops and there are many different situations that require waterstops. Waterstops are used in walls, in floors and in roofs of underground structures.
Making the earth-sheltered building secure from water infiltration is more essential than it is for above-ground buildings because repairs, if needed, are much harder to make.
