Moisture control of CLT in the design phase

The construction industry stands in front of several challenges when it comes to sustainability where the choice of material can affect the carbon dioxide emissions. The interest to use CLT has increased the last years probably due to increased environmental awareness. Studies have shown that there is a research need when it comes to moisture in CLT which this report have looked deeper in to. The purpose was to create a bigger understanding for moisture protection of CLT in the design phase. The method was a qualitive case study where the main data collection was interviews. Complimentary material to the primary data was gathered through a document study to answer the first research question. This created a triangulation and strengthened the reliability of the study. A literature search was implemented to create a scientific foundation to the study. Three reference objects were the basis for the study where architects, constructors, contractors and moisture consultants were interviewed. The results of this study showed that the industry standard for building moisture safe constructions ByggaF is used as a foundation for the moisture work but is adjusted to the project. The work with moisture protection begins in the project planning document phase and continues throughout the whole process of the project. The moisture consultant reviews and follow up the work continually. The study also shows that there is lack of experience when it comes to CLT in the industry. Challenges that occurred were inadequate communication between different disciplines. The areas for improvement in the industry are that a library with standard details should be developed. It also occurred that it is important to include a moisture consultant and supplier of CLT early in the project. The study showed that there is shortage in experience when it comes to moisture control of CLT. Shortage in experience can result in CLT being deselected as an alternative to concrete. It also appears that there are challenges with the communication to production which is probably a consequence of lack of experiences. The possibilities of CLT are many since it is a sustainable material, easy to assemble and creates a nice environment. By further education and sharing experiences, the knowledge regarding CLT and moisture in the industry can increase. For an easier design phase, a library with standard details should be developed as well as further tools in the form of an agenda that treats general moisture control. The question regarding weather protection is something that has been discussed which sets different requirements for the design phase and there is a need for further research regarding this question.