Balustrades and barriers – water entry/deterioration of solid balustrade

Causes

Hairline cracking in monolithic (plaster) cladding

The handrail is fixed to the top of solid balustrade wall

There is no flashing or an inadequate flashing to the top of the solid balustrade wall

There is a reliance on the plaster finish to provide waterproofing

Common

Listed under: Exterior, plaster and fibrous plaster, barriers and balustrades, handrails, moisture, leaks, weathertightness, solid plaster

Cause

Hairline cracking in monolithic (plaster) cladding

Repair

  • it is likely that the balustrade wall will need to be rebuilt with the appropriate flashings and design to prevent leaks. If the balustrade or barrier was constructed in the last 10 years, call the original contractor back
  • where it is suspected that there may be rainwater entry into the balustrade, engage an experienced building surveyor to investigate and advise on repair options. The surveyor should be a member of an industry body such as the New Zealand Institute of Building Surveyors
  • for new construction, the requirements around parapets and enclosed balustrades are set out in the Acceptable Solution E2/AS1 (including Figures 10, 11 and 12)
  • the top must be protected with a cap flashing of metal with a minimum fall of 5° (section 6.4) or membrane (such as butyl rubber or EPDM) with a minimum fall of 10° (section 6.5). There are many other design requirements
  • handrail fixings must be made into the framing only through the vertical face of the balustrade cladding (E2/AS1 Figure 19). Use the minimum number of fixings practicable for support and incorporate neoprene or EPDM washers and sealant at the cladding penetration
  • in almost all cases, repair or rebuilding work should be carried out by an experienced licensed building practitioner. Balustrades are a relatively complex element to construct – particularly the flashings at the balustrade-to-wall junction. A DIY solution should only be contemplated by someone with the knowledge, experience, skills and tools to do the job competently. Inappropriate repairs may create further problems in the long run

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Cause

The handrail is fixed to the top of solid balustrade wall

Repair

  • handrail fixings must be made into the framing only through the vertical face of the balustrade cladding (E2/AS1 Figure 19). Use the minimum number of fixings practicable for support and incorporate neoprene or EPDM washers and sealant at the cladding penetration
  • fixing of handrails into the vertical face has been a Building Code requirement for over a decade. If the balustrade was constructed in the last 10 years, call the original contractor back  
  • see the first repair above for more details

 

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Cause

There is no flashing or an inadequate flashing to the top of the solid balustrade wall

Repair

  • flashings have been a Building Code requirement for over a decade. If the balustrade was constructed in the last 10 years, call the original contractor back  
  • see the first repair above for more details

 

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Cause

There is a reliance on the plaster finish to provide waterproofing

Repair

  • a plaster finish cannot be relied on to provide sufficient waterproofing. If the balustrade was constructed in the last 10 years, call the original contractor back  
  • see the first repair above for more details

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