Specialist damp and timber report - chimneys

Johnjones7656

Advised to get a specialist damp and timber report in structural survey but instead of answering questions it just seems to have thrown up more questions....they've advised getting a quote from a roofer for the following:


'I believe the damp noted to the chimneybreasts on the second floor is caused by ingress moisture through the flaunching and rear cloaking of the chimneys. The chimneys are also likely to be sweating due to the lack of ventilation.
Further inspection is required to the detail between the ridge tiles and flashings to the chimneys on the left of the roof. The flaunching should also be inspected and renewed if necessary. I would also recommend the inclusion of vents to the chimney stacks.
Second Floor – Chimneys:
The affected plaster to the chimney walls on the second floor will hold contaminants even after the area has dried out, therefore I would recommend the removal of the affected plaster followed by the application of a cementitious tanking agent, followed by specialist re-plastering.'


Anyone able to help me decipher this please???

Johnjones7656

Anyone able to help?? Is it a big job or small job?

Doozergirl

You need a roofer to examine the chimney and rectify any issues. The surveyor has used clear building language, but to provide simple terms to a layperson, it sounds like the bits that stick a chimney together and make it watertight are are generally deteriorating. There's no major structural issue apparent.

It shouldn't be a huge cost - unless you have a tall house and need scaffolding!

Internally, the chimney should be vented as it has clearly been blocked up. You can eithe re-open it, or drill a core hole and put a vent over. Chimneys do need airflow.

Surveyor is suggesting that you replaster the chimney breast, but I would see first if it can be dried out and redecorated using stain blocker first, unless it's really obvious that the plaster has blown. It won't cost much to wait and see.

teneighty

The flaunching is the sand/cement mortar at the top of the chimney stack. Over time it cracks and allows rainwater to seep into the brickwork.

The rear cloak refers to the lead flashing, Again, over time the lead can split or can simply become dislodged.

The sweating is a poor description, it means there may be condensation forming in the old redundant flue as it is sealed and not ventilated.

Any old flue will have a build up of soot and tar deposits no matter how well it is swept. When you get water penetration it causes chemicals in the soot to seep into the brickwork and plaster. These chemicals can themselves lead to staining in the plaster which are very difficult to mask so often requires replastering.

You are probably looking at around £500 to £1000 of work.