Concrete or clay tiles – roof sagging

Cause

Rafters are inadequately sized for the span and weight of roofing

Repair

  • in older houses such as villas it is not unusual to find structural timbers that are undersized compared to today’s standards. Consult a registered architect, licensed building practitioner or chartered professional engineer to inspect and advise on possible repairs

  • work on roof framing is restricted building work. If you engage a builder, the work must be carried out or supervised by a licensed building practitioner (LBP). You can ask to see the photo licence card of a licensed practitioner

  • homeowners are legally able to carry out restricted building work on their own homes, but they need to complete a statutory declaration with the local council. The fact that they have done this work themselves will be noted on council records and will be accessible by potential future buyers of the house. You should only carry out this sort of work if you have the skills, knowledge, experience and tools to properly do the job

  • radiata pine timber used in a roof space should be treated to a minimum H1.2. In some cases where more significant repairs are required, options may include using steel beams or LVL (laminated veneer lumber) beams. The requirements are found in Section 10 Roof framing, in the standard NZS 3604:2011 Timber-framed buildings.

  • work on roof framing is likely to require a building consent. Contact your local council for details. Any renovation work that requires a building consent will have to comply with the Building Code. Even if building work does not require a building consent, after the work is completed, the building must still comply with the Building Code to at least the same extent as it did before the work was done.

Cause

Insufficient strutting support for the roof weight

Repair

  • as for the first repair above

Cause

Roof framing has been damaged or cut

Repair

  • as for the first repair above

Cause

Loadbearing walls below have been removed

Repair

  • as for the first repair above. It is likely that supporting beams will need to be installed where loadbearing walls have been removed

Cause

Rafters have been damaged by borer or decay

Repair

  • as for the first repair above