Within Sundarban village and in rural areas of Dinajpur district, low-income families frequently use earthen plasters to provide protection to simple bamboo frame construction. This ‘wattle and daub’ solution is subject to heavy rains particularly during the monsoon season along with flash floods and standing water, and therefore requires ongoing maintenance.
With support from Engineers Without Borders UK (EWB-UK) a volunteer architect from the UK is working with SAFE to test and develop earthen plasters with increased water resilience. Low-income households are not often able to afford the inclusion of synthetic additives such as 5% cement or lime and therefore the aim is to test a range of natural additives that are both freely available and can be harvested locally.
Research findings will offer modest improvements for areas with limited assets and should be used in combination with a range of design solutions including the introduction of longer eaves and raised compacted earth plinths.
Over the past few weeks SAFE has been harvesting, collecting, extracting and producing a range of raw materials for the upcoming tests. This includes cactus juice, banana leaf juice, banana plant sap, eucalyptus bark tannin, casein, coal, oil and starch.
The water resilience of earthen plasters with natural additives will be compared to the performance of those with synthetic additives. A number of samples have been ‘thrown’ this week into a timber mould.
Following the drying process, the samples will be subject to external conditions, with changes in appearance and weight noted over time.