A recent home survey unearthed a particularly destructive example of poor construction, in the form of a chimney stack which penetrated the rear roof slope of the property. The extent of the damage was such that, in the chartered surveyor’s opinion, the chimney would have to be pulled down and entirely rebuilt.
The defective condition of the chimney consisted of several cracks in the brickwork at the top of the stack. The render covering the brickwork had suffered significant and noticeable spalling, but as the brickwork itself had separated such that the whole stack showed signs of movement, the surveyor recommended that the chimney was unsafe. It was no longer a question of if it would collapse, but when.
The suspected cause of the destruction was water which had penetrated the render and pebbledash, which had in turn badly deteriorated. Crude repairs were been carried out just above the lead flashing and mortar fillets around the stack (as shown in the photograph above), but this had only exacerbated the problem, preventing trapped moisture from escaping naturally, and causing the brickwork itself to decay.
The stack served a fireplace in the rear reception room, but the flue had not been in use for many years. As the stack was now redundant, the surveyor also suggested that instead of replacement, the stack could be removed and the resulting hole be insulated, covered over and made good, in line with the rest of the roof. This had the added benefit of more fully insulating the roof from damp issues, which according to an inspection of the loft space, had begun to visibly impact the timbers surrounding the chimney flue inside the loft.