Refurbishment options

When flat roofs are in need of refurbishment, it may be possible to retain the existing roof structure and to build up the refurbishment on top. If, on the other hand, the old structure cannot be retained, the old roof waterproofing has to be removed and a completely new structure installed.

Refurbishment on the existing roof waterproofing offers a number of advantages:

• Firstly, there is no need to remove the existing roof structure, a time-consuming and costly job.
• Problems and costs associated with disposing of the old structure are avoided.
• The existing vapour barrier can be used.
• The existing thermal insulation can play its part in energy saving.
  
  

The following requirements must be met for refurbishment on existing roof waterproofing:

• Blisters and creases in the existing roof waterproofing must be removed and repaired.
• Existing thermal insulation must rotproof, and must be dry.
• An effective separating layer between the old and new waterproofing (if required for technical reasons - e.g. if an old bitumen structure is to be refurbished with synthetic roofing membranes).
• Effective protection from wind uplift must be ensured.