Hemp and lime sheating - Technichanvre

For information

« Within a short cycle of 1OO days , one square meter of a concrete wall in a wood frame (thickness of 26 cm) keep from 14 to 35 kg of Co2 eq per m² » this is huge ! (source : INRA study from 2006 for the agricultural and fisheries Ministry : »environmental features of hemp during its life cycle

Main points for a good framework

Temperatures between + 5°C and + 30°C
An adapted wooden framework (example : 145 *45 in Douglas wood)
capilarity felt on the foundation before the framework implementation
Management of technical network (electricity, plumbing..)
steel parts to protect
Woodwork to protect
Manage your time and your product
Manage your work team

Please find all specificities in factsheet framework

technical drawings :

hemp and lime sheating with wooden framework – above view

hemp and lime sheating with wooden framework – front view

hemp and lime sheating with wooden framework implementation

STEP 1 : wooden framework implementation

The framework is a foundation with a bitument based felt for capillarity break

It is important to fix pins in the thickness of the framework for maintaining the mortar in a vertical plan and avoiding projection.
Electrical equipment are fixed in the framework, electric ducts are set up. All these things will be submerged in the mortar.

STEP 2 : preparation of the basement coat

To submerge the framework with the hemp, fix the screws on the edge of the framework. exceed them from 3 to 8 cm in height.
Panels will be put on screws, This shifts them from the framework. After this you can screw the panels in the framework; in this way, you have an empty space between the panel and the framework.
In the case of visible framework, you have to screw the panels in the framework itself (take care of thermal bridges! one of the side of the framework have to be submerged).
NB : all electrical boxes have to be visible after stripping

STEP 3 : the mix and the method

mixed-in-place using shaft pulver mixers or traveling mixing machines. The mixture is filling in the empty spaces of the framework. After the mixture in the hole has settled you don’t have to push on it.
NB : It is possible to fill a wall is its complete height during a day.

STEP 4 : The stripping

With modified lime (grey on pictures), it is possible to stripe the indoor side the next day, and the next week for the outdoor side(not less than 6 days)

STEP 5 : lime milk

For an outdoor covering, the framework is visible. For the sustainability of the mortar, it is highly recommended to use a lime milk over the hemp and lime.