Insecure chimney pot

Causes

Mortar deterioration between chimney and chimney pot

Listed under: masonry, Roof, chimneys and flues and fireplaces, mortar

Cause

Mortar deterioration between chimney and chimney pot

Repair

  • it is common to find that mortar used in the early 20th century is crumbling and loose today

  • chimneys and chimney pots that are no longer structurally sound or secure can be dangerous, particularly in an earthquake. Take prompt action

  • where the structure of the chimney itself is sound, and there is a wish to retain the original chimney pot for the appearance of the house, the pot should be removed, cleaned and then reinstalled with mortar. Replica chimney pots made from terracotta or lightweight materials such as fiberglass are also available

  • if the appearance is not important, replacing with a metal cowl is another option

  • check the condition of the mortar in the chimney itself. With very old chimneys, it may be a good time to consider whether the chimney is structurally secure or even required any more. Part-removal is possible, with just the element above the roofline being dismantled. Removal of a structurally unsound chimney does not require a building consent. This exemption is limited to any building up to 3 storeys high as long as the removal does not affect the primary structure, any specified system or any fire separation (which includes firewalls protecting other property). Any necessary repair work, such as making good the gaps left in a roof after chimney removal, can also be done without a consent

  • the Building Act states that after the repairs/renovations are finished, the building must comply with the Building Code to at least the same level as it did before the work started
  • you should only attempt these repairs yourself if you have the skills, knowledge, experience and tools to complete the job properly. Poor quality work on the building exterior can result in leaks and other problems and may affect your house insurance cover

  • always tell someone else when you plan to work on a roof and take the appropriate safety precautions. You can find details here

  • if you engage a tradesperson to remove a chimney and complete any necessary repairs to the roof or wall, that person must be a licensed building practitioner or work under the supervision of a licensed practitioner. You can ask an LBP to show you their ID card – they have a duty to show you if asked. You can find an LBP, or check that someone is licensed, online.

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