To discuss your project give us a call on 01392 861763


Here you’ll find our latest how to guides, videos and analysis of materials.

Breathable render for EWI – Baumit OpenContact

Product Data Sheet Baumit openContact

Factory prepared mineral based, natural white, vapour-permeable dry powder adhesive and basecoat render mortar. Suitable for manual and machine application. A system component for the Baumit openSystem external wall Insulation system. Tested according to ETAG 004.  Dual purpose contact mortar: As an adhesive for bonding Baumit facade insulation boards and a thin layer basecoat (with reinforcing mesh) onto Baumit façade insulation boards. Properties: Composition: Technical Data:  Vapour permeable, high bonding strength, water resistant and good workability. White cement, organic binders, sands and additives. Aggregate size: 0.6 mm : 1 mm Dry bulk density: ca. 1350 kg/m³ Thermal conductivity λ: ca. 0. 8 W/mK Water vapour diffusion resistance μ value: ca. 18 Sd: -value: 0.05 m (at 3 mm thickness) Water requirement: ca. 6 l/ 25 kg sack Minimum basecoat thickness: Refer to table below Consumption as basecoat: ca. 5.0 – 6.0 kg/m² Consumption as adhesive: ca. 4.0 – 5.0 kg/m²

CPD Training

We offer CPD training for architects practices across Devon and Cornwall.

Software Modelling

We offer dynamic heat and moisture modelling as well as condensation risk analyses.

Building Plan Review

If you have some plans and would like our opinion on which materials would be the best for you, contact us.


Back to Earth is a natural building material supplier. We're not your typical builders'​ merchant though and instead work closely with our clients during the planning, designing and building phases of projects.

Back to Earth is a proud signatory of the Anti-Greenwash Charter:

© 2023 Back to Earth