Timber-framed barn Saint-Samson-la-Poterie - Internal Insulation - Hemp wool insulation - 200 mm

The solution consists in insulating the inner side of a timber-framed wall with 20 cm of hemp wool on a wood frame. It was then rendered with an earth plaster which was applied to a tightly latticed partition made of chestnut slats. No airtightness membrane was installed because the render was considered naturally airtight because of a good dosage of the components and a excellent implementation with good execution of the works. The exterior facades were rendered with a lime and clay plaster on the wattle parts filled with daub to let the timber-framing visible.

An internal insulation was well adapted to this timber-framed building with no interior heritage elements and wouldn't hide the wooden frames that have a strong heritage value in the region. Besides, hemp wool is a bio-based insulation solution that is well adapted to hygrothermal behaviour of heritage buildings especially those with cob. Like cob, this combination of hemp wool and earth render is permeable so moisture can migrate from the inside through the outside. The inside earth render ensure the airtightness barrier of the whole complex while the hemp wool guarantees limits thermal losses. No metal components were used, only wooden structure, in order to avoid thermal bridges.