Thatched roof constructions

Considerations thatched roofs:

The airtightness of the substructure for thatched roofs screw is very important. By insufficient airtightness can warm moist air in the construction, with condensation and rotting reeds as a possible consequence. Is the substructure good damp proof (hence airtight) and is processed during construction well and dry reeds, dry, then the closed structure in themselves behave well and only the outer 3-5 cm in wet precipitation.

When it is warmer inside than outside, there will be in a heated building, under the thatched roof a higher vapor pressure than outside arise. In the Netherlands this especially in autumn, winter and early spring the case. Under the influence of this differential pressure (pressure diffusion) will moisture (moisture and living in the first two years also building moisture) in the building outward ‘pressed’ are – also through the roof and the reeds package. The driving force behind this vapor transport is the temperature difference between inside and outside, and the difference in humidity. Is the substructure sufficiently damp proof and / or there is too much moisture during construction ended in the package, then the roof in 3 to 8 years or perish dust (under a low algae choke).