In view of cracks existed generally in floors and walls of cast-in-place dwelling house engineering,the author analyzes the reasons which caused cracks and put forward a method,just as done in road engineering,which can control cracks through making "fake crack"in cast-in-place concrete roof.

The techniques adopted include UEA concrete expansive agent mixing, external waterproof coating and four-sections constructing, furthermore, "post-grouting fake cracks" have been settled between different sections by which post-grouting belts are cancelled, thus the constructing was accelerated, and perfect waterproofing effect is achieved as a result.