The SD (Steam Diffusion) value is a German method for measuring breathability. It is widely accepted that for a paint to be classed as breathable it should have an SD value of 1 or lower; the lower the value the more breathable the paint. The SD values for our two most breathable paints have been measured as follows:
Earthborn Claypaint (for interior walls and ceilings) – SD: 0.02m.
Earthborn Ecopro Silicate Masonry Paint (for exterior masonry surfaces) – SD: 0.06m.
The MVTR (Moisture Vapour Transmission Rate) measures the amount of water vapour (in grams) able to pass through the paint surface over a 24 hour period. The higher the figure, the more water vapour that can pass through, and therefore the more breathable the paint. The MVTR values for our two most breathable paints have been measured as follows:
Earthborn Claypaint (for interior walls and ceilings) – MVTR: 1115g/m2/24h.
Earthborn Ecopro Silicate Masonry Paint (for exterior masonry surfaces) – MVTR: 1264g/m2/24h.