Launch of PARNATUR?, the first “easy-to-spray” thermal and phonic insulation hemp based mortar: Since 2015, the Sika company Parex has achieved a 5% reduction in its greenhouse gas emissions in France. With an ever greater focus on the circular economy and finding ways of preventing climate change, projects that involve the use of recycled or bio-sourced raw materials were given priority.

Reducing Energy Consumption in Buildings by Using Hemp-Based Mortars

Sika Researchers in Lyon, France
Image: Sika Researchers in Lyon, France
Launch of PARNATUR?, the first “easy-to-spray” thermal and phonic insulation hemp based mortar.

Since 2015, the Sika company Parex has achieved a 5% reduction in its greenhouse gas emissions in France. With an ever greater focus on the circular economy and finding ways of preventing climate change, projects that involve the use of recycled or bio-sourced raw materials were given priority.? The company contributes to the structuring of agricultural channels by promoting the use of bio-sourced aggregates in the building industry. To this effect, a number of collaborative projects sponsored by the French Environment & Energy Management Agency, ADEME, are aimed at producing thermal and phonic insulation mortars containing bio-sourced aggregates, such as hemp.

Thermal and phonic insulation

Hemp is a natural material suitable for making lightweight insulating mortars. Its density varies between 110 and 150 kg per m3?and the strands are between 2 and 10mm long. The thermal conductivity of hemp in bulk is 0.04 W/m.K.? Particular attention has to be paid in making sure that hemp is not subject to humidity, either due to stocking conditions of the raw material or capillary action in hemp mortars. Parex France is now launching a breakthrough innovation developed by the R&D Team of Evelyne Prat and sponsored by Ademe, the French Environment & Energy Agency. Three worldwide patents have been secured.

The pumpable hemp-based insulating mortar has been tested and proved as an ideal solution to decrease thermal leakage across walls. Energy consumption can be reduced by up to 45%? which corresponds to annual cost savings of CHF 2,000 for a home of 100 m2.

Benefits of the hemp-based solution

Hemp concrete is a 100% natural solution with a high CO2 storage coefficient and is fully recyclable. Thermal conductivity achieved by PARNATUR? is very low: 0,066 W/m.K ( at 23°C – 50% Relative Humidity). The main characteristics of hemp concrete in this application are:

  • Provides thermal and phonic insulation benefits thanks to the continuous envelope that prevents thermal leakage
  • Suitable for both new constructions and for renovation of existing buildings.
  • Perfect for renovation and leveling of uneven surfaces since thickness of the coat can be adapted
  • Respects the breathability of old walls providing optimum air interior comfort
  • Low carbon footprint material.Consistency of? thermal insulation thanks to an even distribution of hemp aggregates in a continuous light weight cementitious matrix
  • Easy to apply with a standard spraying machine
  • Quick setting and hardening, allowing structures to be secured very early on
  • Mixing: 25 kg of binder + 100 litres of hemp shive + Putzmeister SP 11

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