Hendon Hall, Hendon, London

Hendon Hall is Grade II listed and was built in the 1750’s.  In front of the facade is an stonishing full height portico said to come from Canons via Wanstead, from whence it would have been purchased after the 1822 sale and demolition.

The Hall was a hotel up until recently and was where the England 1966 world cup team stayed the night before the finals.

Alterations and refurbishment of the building required an assessment of the strength of the floors.  EBS Ltd was asked to carry out visual stress grading and species identification of the timbers on behalf of the engineers.

Visual stress grading allows a means of assessing the strength of a timber in-situ.  EBS Ltd carried out a visual grading of the timbers, classifying them into GS (C16) or SS (C24) grades according to the rules described in BS 4978: 2007 (Softwoods) and BS 5756: 2007 (Hardwoods).  The knot area ratio, slope of grain, growth ring spacing and defects such as splits and bark pockets are identified, then a grade is assigned to the timber.  Where a timber can only be seen partially a grade is given to that section only.

Engineers and designers converting existing buildings often want to know what load the existing timbers can carry. The process requires that the full length of the timber to be assessed, is visible with no paint finishes.

The timber strength is dependent on its species.  In order to assess the timber species a small sample of the timber is removed to allow the gross anatomical features to be assessed.  Microscopic inspection may also be carried out to allow inspection of the anatomical features which are compared with published literature or known samples.