INTRODUCTION

The roof is sometimes called the fifth facade of a house. Roof structures are essential parts of building envelopes and are usually the building structure which must endure the most extreme exterior climate conditions. Roofs can be designed in numerous ways and, along with the roof covering, could play definitive role in the appearance of the house. It could, alternatively, be barely visible and only serve as an integral part of the functioning of the building envelope. As part of the building envelope, the roof is subject to strict performance requirements shaping the choice of materials, assembly, and installation of the roof structure for it to function optimally and durably.

The Guidelines explain how to install roofs that comply with the provisions of the 2018 Danish Building Regulations (The Danish Transport, Construction and Housing Authority, 2017) concerning watertightness, drainage, heat loss, fire safety, personal safety, and other performance related concerns. 

The Guidelines cover the assembly of roofs from the interior ceiling finish to the exterior roof covering, including vapour barriers, thermal insulation, roofing underlayment, and spacer bars.

The scope of the Guidelines covers the whole roof assembly except for supporting structures. Consequently, the following topics fall outside the scope of this book: bracing structures for the roof assembly, sizing of rafters, purlins, and battens. For timber roof assemblies, see for example; SBi Guidelines 254, Småhuse – styrke og stabilitet (Small Houses – Strength and Stability) (Cornelius, 2015) and the publications and calculation programmes available from Træinformation (Centre of Excellence in Timber Construction). As the bracing of roof assemblies using timber rafters is often poorly executed, see; TRÆ 58, Træspær 2 – Valg, opstilling og afstivning (Timber rafters 2 – choice, installation, and bracing) (Træinformation, 2009b), TRÆ 60, Træplader (TRÆ 60, Timber Sheets) (Træinformation, 2012), and Træ 73, Tagkonstruktioner med store spær (Træ 73, Roof Assemblies Using Large-Scale Rafters) (Træinformation, 2017). For concrete roof assemblies, see e.g., Betonelementer (Concrete Slabs) (Betonelement-Foreningen, 1991). For steel roofs assemblies, see Stålkonstruktioner efter DS/EN 1993 (Steel Construction According to DS/EN 1993) (Bonnerup, Jensen & Plum, 2015).

Multi-storey buildings and integrated single-family dwellings are subject to special requirements regarding acoustic insulation and the control of the spread of fire via the roof structure, see SBi Guidelines 237, Lydisolering mellem boliger – nybyggeri (Inter-Dwelling Acoustic Insulation – New Build) (Rasmussen, Petersen & Hoffmeyer, 2011) and SBi Guidelines 253, Småhuse – indretning og funktion (Small Houses – Layout and Function) (de Place Hansen, et al., 2015). Concerning fire safety, please consult the Danish Building Regulations instructions on fire performance. See www.bygningsreglementet.dk for further information.

The following terms are used in the Guidelines:

In many cases, the figures in the Guidelines are schematic drawings.

Other figures show examples of possible solutions, but other solutions may exist.