Loss of mineral chip coating in torch-on bitumen roofing membrane

Loss of mineral chip protective coating in torch-on modified bitumen roofing membrane

Causes

Age

UV light degradation 

Damage from foot traffic

Listed under: membranes, Roof, cladding, roof cladding

Cause

Age

Repair

  • very minor loss of chip coating may not be a problem. You could ask a membrane supplier/installer to look at the roof and give you their opinion
  • in some cases applying a coating to the membrane may help extend its life, but this should only be done following specific recommendations from the membrane manufacturer/supplier.
  • DIY work on membrane roofs is not recommended. Membrane manufacturers/suppliers typically train and license applicators in the use of their membranes. Repairs or replacements should also be carried out by these trained/approved applicators. Work that is incompatible with the original membrane system may void the warranty and could even make the problem worse
  • where the problem is severe and extends over a wide area and the membrane is nearing the end of its serviceable life, replacing the whole membrane may be a better long-term solution than just a repair
  • if the existing membrane must be replaced, and it has not met minimum Building Code durability provisions (15 years), a building consent will be required
  • after repair or replacement, check the roof once a year to ensure it is in sound condition

Back to top

Cause

UV light degradation 

Repair

  • as for the first repair

Back to top

Cause

Damage from foot traffic

Repair

  • follow the repair advice above
  • try to avoid foot traffic on the roofing membrane. Work out why there has been foot traffic in the past. If people have walked on the membrane to trim trees, for example, the tree branches could be cut back so roof access is no longer required
  • if foot traffic is unavoidable, then protect the roofing where possible, and if/when the membrane is replaced, replace it with a material that allows foot traffic

Back to top