Achieving airtightness and weather protection of CLT buildings

Moll bauökologische Produkte GmbH, 68723 Schwetzingen, Germany

^* Jens Lüder Herms: jens.lueder.herms@proclima.de

Abstract

CLT buildings - a critical view concerning airtightness and weather protection during building time. Wood constructions are gaining a bigger and bigger share in the building industry as well in bigger constructions. Mainly CLT (Cross-Laminated-Timber) elements are due to it’s stability, fast building up time, easy installation and high share of prefabrication a key point for this success. In this presentation I will take a critical view on the building physical properties like diffusion resistance and airtightness. Especially according to the normal building material properties of wood like swelling and dwindling of timber. As well we will take a closer look to different glue technologies which are used on adhesive tapes to seal the CLT elements airtight. There are different technologies available in the market which offer different quality levels. Another point to solve is the temporary weather protection of timber building due to an enlarged building time. Especially when we have visible surface in the walls or in the ceiling they must be protected against rain water – there are new self sticking membranes available in the market which have proven their ability to protect ceilings against rain in a large number of realised constructions. The performance of these products will be presented in some already realised projects and we will take a closer look at the requirements and problems which have been found in these projects.