Leaking through stucco

Stucco has been used as a house cladding in New Zealand since the 1930s. Where a stucco house was built around the mid 1990s to the mid/late 2000s (particularly one with waterproof decks, parapets, no eaves and a complex design), engaging a registered building surveyor with experience in leaky homes is strongly recommended. DIY repairs and repairs by non-specialist builders often do not solve the problem and may result in further problems. See our Weathertight guide for more details.

Causes

Cracks in the cladding systems

Paint or sealant failure

No cap or saddle flashings at junctions of parapet and balcony walls

Junctions with other claddings and/or roof poorly detailed/constructed

Omission of head flashings to doors/windows

Minimal jamb flange cover of aluminium windows

Common

Cause

Cracks in the cladding systems

Repair

  • engage a registered building surveyor to report on the building. Any subsequent repair work to consequential damage, if required, should be fully documented and carried out by a contractor with experience in this type of work. A building consent will be required

  • where there is no consequential damage identified by the building surveyor as a result of the cracks, seal the existing cracks and apply a new coating system to the plaster

Cause

Paint or sealant failure

Repair

  • engage a registered building surveyor to report on the building. Any subsequent repair work to consequential damage, if required, should be fully documented and carried out by a contractor with experience in this type of work. A building consent will be required

  • where there is no consequential damage identified by the building surveyor as a result of the paint or sealant failure, the wall performance may be reinstated by the application of a new coating system to the plaster

Cause

No cap or saddle flashings at junctions of parapet and balcony walls

Repair

  • engage a registered building surveyor to report on the building. Any subsequent repair work to consequential damage, if required, should be fully documented and carried out by a contractor with experience in this type of work. A building consent will be required

  • where there is no consequential damage identified by the building surveyor as a result of the flashing failure, the wall performance may be reinstated by the installing of new flashings

Cause

Junctions with other claddings and/or roof poorly detailed/constructed

Repair

  • engage a registered building surveyor to report on the building. Any subsequent repair work to consequential damage, if required, should be fully documented and carried out by a contractor with experience in this type of work. A building consent will be required

Cause

Omission of head flashings to doors/windows

Repair

  • engage a registered building surveyor to report on the building. Any subsequent repair work to consequential damage, if required, should be fully documented and carried out by a contractor with experience in this type of work. A building consent will be required

  • where there is no consequential damage identified by the building surveyor as a result of the flashing failure, the wall performance may be reinstated by the installing of new flashings

Cause

Minimal jamb flange cover of aluminium windows

Repair

  • engage a registered building surveyor to report on the building. Any subsequent repair work to consequential damage, if required, should be fully documented and carried out by a contractor with experience in this type of work. A building consent will be required

  • where there is no consequential damage identified by the building surveyor as a result of the flashing failure, install 30 mm wide scribers butted and sealed to the flange or facings rebated over the flange to aluminium window jambs

  • consider replacing existing aluminium windows with frames that have larger jamb flanges