Fibre-cement cladding – sealant cracking or degradation
Listed under: Exterior, adhesives and sealants, sealants, concrete and cement, fibre-cement, cladding, walls, moisture, leaks, wall cladding, fibre-cement cladding
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