Waterproof decks – delamination of membrane from substrate

Causes

Poor adhesion of the membrane to the substrate

For liquid applied membranes, the application had not cured properly before subsequent coats were applied

Listed under: Exterior, membranes, balconies, cladding, decks

Cause

Poor adhesion of the membrane to the substrate

Repair

  • where the problem is extremely minor with no risk of leaks, watching to see whether it gets worse may be an appropriate first response. Where significant areas are not properly adhered, the membrane should be removed and replaced with a material compatible with the substrate

  • if the membrane was installed in recent years, call the installer back. Roofs still under warranty should be repaired by the contractor who carried out the original membrane application or by another applicator approved by the membrane supplier

  • installation and/or repair of membranes is not a DIY job. Membrane manufacturers and suppliers typically train and license applicators in the use of their products. A warranty may only apply where application or repair is carried out by someone licensed by the supplier

  • work on roofs is restricted building work under the Building Act and anyone engaged to carry out this work must be a licensed building practitioner or be supervised by an LBP

Back to top

Cause

For liquid applied membranes, the application had not cured properly before subsequent coats were applied

Repair

  • as for the first repair above. Repair work should ensure the repair avoids a repeat of the problem

Back to top