Edited sentence: Although the tops of the white brick walls on the east and west elevations are fixed to the roof to stabilise it, the floating-roof effect is continued with a top row of dark blue engineering bricks with dark pointing.The columns between the windows do not appear to meet the roof when viewed from below: this gives a floating-roof effect.This row is clearly shown in a photograph in the Blackheath Reporter.Viewed from below, this row can look like a gap between wall and roof