Sd values - What are Breathable Paints
A breathable paint is one that allows water vapour to travel or permeate through it. Paints with high rates of permeability allow water to evaporate away rapidly while those with a low permeability are likely to trap moisture. These values are measure as an Sd value. An Sd value will measure how much of a barrier the material is to water vapour so therefore a lower figure is more breathable.
Typical vapour permeable or breathable paints have an Sd value of around 0.02m to 0.5m.
This would mean that an Sd value of 0.3 is the equivalent to 30cm of air barrier. Non-vapour permeable paint with an Sd value of e.g. 3 is the equivalent of 300cm of an air barrier, making it unable to breathe.
Paints with high Sd values have a detrimental effect on the surface they are applied to as they do not allow it to breathe. Most non breathable paints will not usually disclose their Sd values as they can be much higher than 3. Paints with an Sd value of <0.1 offer adequate breathability to cope with most applications.
Ecos paints Sd values
limewash = 0.01
Matt/super chalky/distemper/claypaint/carrara = ~ 0.04
Soft Sheen/gloss/satin/eggshell/masonry/primer/undercoat = ~ 0.08
Formaldehyde - Intertek results & interpretation
Lakeland Matt paint = EVA-based paints, worst case scenario
Lakeland Gloss paint = Acrylic-based paints, worst case scenario.
Both types show No formaldehyde detected by HPLC – this is less than 0.000102mg/L.
0.000102mg/L means less than 0.000102ppm (parts per million)
and means less than 0.0000000102%
Emission criteria by product type
Maximum TVOC content for paints and coatings
Certificates
TOXICOLOGICAL RISK ASSESSMENT (TRA) & LHAMA REVIEW (ASTM D-4236) - PDF
EN71 2018 heavy metals results 233983 - PDF
Eurofins VOC satin eurofins - PDF
Eurofins VOC eggshell eurofins - PDF