Fibre-cement cladding – sealant cracking or degradation

Cause

UV exposure

Repair

  • fully remove all sealant from the joint, insert backing rod or bond breaker tape and apply and tool off new sealant suitable for the in-use environment
  • obtain advice on correct sealant for the material and joint size
  • use a paintable sealant if the wall is to be painted
  • where it is suspected that the building may be leaking and there is a risk of damage behind the cladding, engage an experienced New Zealand Institute of Building Surveyors (NZIBS) building surveyor to report on the building

Cause

Sealant not suitable for being painted 

Repair

  • fully remove all sealant from the joint, insert backing rod or bond breaker tape and apply and tool off new sealant suitable for the in-use environment
  • obtain advice on correct sealant for the material and joint size
  • use a paintable sealant if the wall is to be painted
  • where it is suspected that the building may be leaking and there is a risk of damage behind the cladding, engage an experienced New Zealand Institute of Building Surveyors (NZIBS) building surveyor to report on the building

Cause

Too much movement for the grade of sealant 

Repair

  • fully remove all sealant from the joint, insert backing rod or bond breaker tape and apply and tool off new sealant suitable for the in-use environment
  • obtain advice on correct sealant for the material and joint size
  • use a paintable sealant if the wall is to be painted
  • where it is suspected that the building may be leaking and there is a risk of damage behind the cladding, engage an experienced New Zealand Institute of Building Surveyors (NZIBS) building surveyor to report on the building

Cause

Sealant not installed over a backing rod or bond breaker tape

Repair

  • fully remove all sealant from the joint, insert backing rod or bond breaker tape and apply and tool off new sealant suitable for the in-use environment
  • obtain advice on correct sealant for the material and joint size
  • use a paintable sealant if the wall is to be painted
  • where it is suspected that the building may be leaking and there is a risk of damage behind the cladding, engage an experienced New Zealand Institute of Building Surveyors (NZIBS) building surveyor to report on the building

Cause

Sealant at end of its serviceable life

Repair

  • fully remove all sealant from the joint, insert backing rod or bond breaker tape and apply and tool off new sealant suitable for the in-use environment
  • obtain advice on correct sealant for the material and joint size
  • use a paintable sealant if the wall is to be painted
  • where it is suspected that the building may be leaking and there is a risk of damage behind the cladding, engage an experienced New Zealand Institute of Building Surveyors (NZIBS) building surveyor to report on the building