Today we came across some rather old cob walls.
Today i had the pleasure of inspecting a garage building which was suffering structural issues as a result of a near sycamore trees. The site was surrounded by large walls, which looked to be chalk built. Upon closer inspection it revealed that these were infact known as ‘cob walls’. Cob walls seem to be common throughout Test Valley villages where by chalk is the main structural element used for the cob. The builders here may have utilised local chalky substrate to form such walls.
Cob walls can be found throughout other localised parts of the UK. Cob is not always just chalk and can often consist of other elements such as chalk, straw, lime and urine. Yes, urine from cows! Cob walls are vulnerable to damp & when saturated may be susceptible to collapse. We’ve found these type of walls to be constructed on very shallow foundations before & in some cases none at all.
The image above shows a cementious repair to the corner of the building which has suffered from subsidence. I can only suggest that the defective rainwater pipe has played part in the ground saturation causing such movement. Note how the downpipe discharges at the base of the wall & the guttering is warped. This structural failure could have been prevented with simple maintenance and thought for rainwater discharge. Over time, the ground may have saturated so much leading to the shallow foundations failing. The growth of some shrubbery against the adjoining wall may present other failures, but that’s another story! Nevertheless, it was nice to see some examples of traditional earth walls in my home county of Hampshire.