Sheet membrane roofing – deterioration along substrate joints

Cause

Movement in the plywood substrate

Repair

  • monitor the membrane closely. If the roofing was installed relatively recently – within the last few years – call back the original installer to have a look at it. Roofs still under warranty should only be repaired by the contractor who carried out the original membrane application or by another applicator approved by the membrane supplier

  • membrane manufacturers and suppliers typically train and license applicators in the use of their membranes. If repairs are made that are incompatible with the original membrane, the warranty for the original membrane may be void

  • application or replacement of roofing membranes is restricted building work and must be carried out or supervised by a licensed building practitioner with the relevant licence class

  • if the problems mean the existing membrane must be replaced, and it has not met minimum Building Code durability provisions applicable (15 years), a building consent will be required

Cause

Omission of bond breaker tape at joints 

Repair

  • as above. If the problem is the result of faulty installation, the repair should be made at the cost of the installer