Architectural joinery design to prevent water leakage in a precast concrete detached house

Abstract

The precast concrete construction is widely used in Thailand by customers and developers for residential development. For many decades of building with the precast concrete wall system, the common problems of water leakage are the most pressing concerns. This thesis aims to find the issues that lead to the causes of water penetration and propose a solution to prevent water leakage. From the literature review, the sources of water leakage are at the connection location between the precast modules. The water can penetrate through the opening with the four forces: a momentum of the raindrop, capillary action, gravity, and air pressure. This thesis categorized the precast concrete joinery into three types of a one-stage joint, a two-stage joint, and a drain joint. The experiment on water infiltration was conducted based on the two leading forces of water leakage with water on the surface test for gravity force and a water spray test for the raindrop momentum (wind-driven rains). The six precast concrete wall modules are setup where three modules do not have a scarf detail, and three modules had a one-way scarf detail. The result shows that the most efficient joinery types are the one-stage joint but, due to the high chance of defection, make the joint more likely to cause water leakage. The second useful joinery is a drain joint with scarfs details with the lowest change of temperature on the two water tests. The research finding of this thesis is used for redesigns the Centro Rangsit village(phase 2) which is a two-story detached house. The project used a precast concrete wall system. The redesign had implemented the modularity in space planning, the panels division that reduces the point of connection, and incorporates the additional element to deflect and discharge the water away from the building surface. Based on the water infiltration experiment, the redesign integrates the scarf drain joinery types. This thesis proposed a redesign that improves the three house modules of the Centro Rangsit village(phase 2) that increases the water leakage prevention mechanism.