https://www.mdu.se/

Purpose: The purpose with this work has been to investigate and map selected fireprotection methods in a number of projects. The possibilities and limitations with exposedCLT have been investigated. Method: The method consists of a literature study, interviewstudy, construction site visit and survey. The literature study has been carried out with theaim of presenting relevant facts to the subject and creating a basis for the interview study.The interviews were conducted with fire consultants for the work´s investigated projects.Two of the projects also included construction site visit, of which one of the projects belongsto the partner of this work, Peab. During the visits of the construction sites a tour of thebuilding were carried out and shown where the exposed CLT was placed. The results from theinterviews and construction sites visits are the basis for the survey. Results: The resultsshow that analytical dimension of the fire protection is required when constructing multistory residence with internally exposed CLT. Limitations with exposed CLT are due, amongother things, to the fact that untreated wood does not fulfils the requirements set in BBR forthe surface layer. Delamination contributes to increased fire load as the underlaying slats areexposed to fire. The current study contains two projects carried out with exposed CLT,Notuddsparken and ETC apartment buildings. The projects have dimensioned each withanalytical dimension but with different fire protection methods. Notuddsparken has beenconstructed with automatic sprinkler systems and the ETC apartment buildings have beenconstructed with fire protection impregnation of the exposed CLT. Conclusions:Conclusions established in the work shows that when using exposed CLT analyticaldimension of the fire protection is required. Most of the fire consultants in this work haveexpressed that they do not feel comfortable with dimensioning fire protection for buildingswith exposed CLT, based on the current state of knowledge.