Roof replacement

Building Type 1: 1850-1890

Many years of wear and tear on roof coverings, flashings, roof valleys, etc. mean that at some point a whole or partial replacement will be required. Since the lifespans of the aforementioned building parts and materials can be variable, a partial replacement of the roof covering will often be sufficient. In the case of partial repairs, the degraded materials are replaced and the structure is rebuilt according to the original.  

In other cases where the roof erosion is widespread and there is a need for a total replacement, there is now a requirement that the roofing solution be improved e.g. by using a subroof solution that can extend the structure’s normal lifespan and even out some of the differences between the lifespans of other parts.  

If a long-lasting solution is required for the replacement roof covering, it is recommend that a permanent subroof and regulatory ventilation of the roof structure be introduced. A number of illustrated examples, showing how a roof structure can best be constructed to achieve good durability, are shown on the GODE TAGE | DK website. In addition, good advice on a selection of subroof solutions can be found on the DUKO | DK website.

A newer solution for the replacement of slate roofs, which is not yet in general use but expected to gain in popularity, uses no lathing, meaning that the slate tablets are fixed directly onto the permanent subroof (see photo to the left).  

The BVB | DK website includes a number of general recommendations based on many years of accumulated experience from publicly funded building renovation projects.  

Photos: BvB/Kristian Køje and sbs/Graves Simonsen (bottom)