Utvikling av luftlekkasjer i leilighetsbygg

This thesis is written in collaboration with the contractor Backe AS, and looks at various issues regarding air leaks in apartments. The thesis investigates how air leaks develop through a building process, which sealing methods affect the leaks and whether it is possible to estimate air leaks in later construction phases. The purpose of the study is to provide the contractor with information about which sealing methods should be focused on, and make it possible to estimate the leakages in apartments upon completion. In this way, surprises can be avoided by a final check. The assignment explains what air leaks are, how it occurs and why it should be avoided. In addition, the task involves the legislation behind air leaks, how air leaks are measured and materials used for airtightening of buildings. In order to answer the research question, one case study was used, in which four apartments were followed in four different construction phases. The sealing methods in each building phase were mapped and the apartments were pressure tested with and without support pressure. The leaks in the apartments were then compared against each other, in order to map the development of the air leak through the building phases. In order to estimate the leakage, a formula was created based on the air leak through materials, area and the improvement from the measurements in the case study. The formula is based on early phase measurements without support pressure, to estimate the air leak in a later construction phase with support pressure. The results show that the air leaks are reduced by 60.6% from the windshield is mounted to the interior plaster is mounted, where all building phases contribute to the reduction. Furthermore, the results show that there are many different sealing methods that affect the development of air leaks. The different impact of the sealing methods depends largely on the workmanship, where the following sealing methods were considered more challenging: • Tape of the windshield against windows • Grout around windows and doors • Cuffs on diffusion barrier The results from the estimation show a deviation of 20% between the estimation and the measured values from the case study. Based on the deviation and few measurements, the estimation will only give a rough estimate of the leaks in later construction phases