Partially-removed chimney in poor repair

There was chimney stack in poor state of repair on the roof slope of this semi detached property in Southampton.

Specifically the mortar joints were beginning to erode and some future repointing will be required.

Unfortunately, due to an unsuitable vantage point on the Building survey, we were unable to inspect the haunching on the chimney.

The chimney pots appeared to be in reasonable condition however.

As and when any works to the chimneys are carried out we advised that the cement pointing around the chimneys be checked.

Any cracked or severely spalled and damaged pots replaced and the cement appropriately angled to deflect all rainwater away from the centre of the chimney stack.

Chimneys should have a DPC

When chimneys are constructed they are required to be provided with a damp proof course to prevent water being drawn through the brick/block work and into the construction below.

Where the chimney in centrally provided within the roof there is usually ample space within the roof void for the construction to dry out but where on the flank wall if the damp proof course has been omitted, it can lead to dampness internally.

Unfortunately, without the aid of long ladders etc it is often not possible to ascertain whether a damp proof course has been provided.

At the time of our inspection there was no obvious difficulty in this respect.

The junctions between the roof slopes and chimney stack are generally formed with lead flashings.

These are satisfactory and seen to be watertight, however, periodically they will require redressing tight to the roof to ensure a permanent and watertight joint.

Chimney stacks very often bulge and distort as a result of natural weathering caused by wind driven rain, sulphate attack and also attacks by condensation and the products of combustion (soot and salts etc).

Such problems are very often accentuated by lack of a proper flue lining system.

Due to the fact that the chimney breast has been partially removed, we recommend for the chimney flue to be inspected.

Due to the extensive conversion works carried out, we were unable to confirm the condition of the chimney breast in concealed areas, however the buyer was advised to carry out further structural investigations.

Post Author: Frances Traynor