Moisture protection
Moisture protection for CLTPLUS?
It works.
While indoor activities such as cooking, showering and breathing lead to moisture ingress, outdoor factors such as rain and snow and, in summer, high air humidity affect exterior components.
AIRTIGHT + WINDPROOF
The indoor climate, noise pollution, indoor air and energy balance are influenced by the vapour, air and wind tightness of the building components for walls, ceilings and the roof. To prevent unwanted air flow, the inside of the room must be designed as an airtight layer and the outside of the building as a windtight layer by sealing all component joints with sealing or adhesive tape.
UNCONTROLLED EXPOSURE TO MOISTURE CAN
- lead to the formation of germs and odours
- lead to an increase in thermal conductivity, which results in increased energy requirements and subsequently higher heating costs
- be the main cause of structural damage due to the influence of water
FAQ
Moisture protection
The individual lamellas are glued on the narrow side to form a single-layer panel creating a high level of airtightness. The CLTPLUS elements from THEURL have been tested for airtightness by Holzforschung Austria. This airtightness test of CLTPLUS was performed in accordance with ÖNORM EN 12114:2000. The result: The test showed that both test specimens 60 mm 3-ply and 100 mm 5-ply can be assumed to be airtight under the specified boundary conditions. The requirements were met during the test and it can therefore be assumed that CLTPLUS is airtight from a thickness of 60 mm and more.
This means that CLT can absorb and release moisture to regulate the indoor climate and allow a small amount of moisture to pass through. For comparison, a vapour barrier with an SD value of 5m, as required for timber frame buildings, has a similar vapour pressure resistance to a 100mm CLT wall.
Uncontrolled air and moisture transport through convection is the most common cause of moisture damage to building components, as the amount of moisture is many times higher than with water vapour diffusion. The essential characteristic of solid wood elements such as CLTPLUS is the diffusion-open construction method, which enables the unhindered movement of water vapour through the individual components to the outside and ensures a pleasant indoor climate.
The water vapour diffusion resistance factor μ for CLTPLUS is 20-50 according to EN ISO 10456, which means that even if the thickness of the cross laminated timber layer acting as a vapour barrier is reduced to a third as a result of joints or transverse tension cracks, condensation will still not form in the construction.
The lower the humidity content, the higher the diffusion resistance. In this context, wood is a highly effective safety buffer. During the heating period, the humidity level indoors is at its lowest, diffusion resistance is at its highest and the flow of water vapour from the inside to the outside is therefore at its strongest. Solid wood panels positioned on the room side are therefore efficient and permanently effective vapour barriers, even without additional component layers.