Overlaying an existing roof

With this option, the existing roof waterproofing is used as a vapour control layer, subject to a detailed examination and an evaluation of how it is attached to the substrate. This will ensure that the new roof will not fail due to wind uplift. Roof overlays can be carried out using Sika Sarnafil adhered, mechanically fastened or loose laid ballasted systems.


John Love, Technical Advisor - East Scotland

Examples of where an overlay would be recommended are:

Advantages of a Roof Overlay

  • Sustainability - No waste/hazardous material
  • Building can remain occupied, with no downtime

Overlay system build-up

1. Existing roof

2. Primer existing surface

3. Primer existing surface using spray applied primer

4. Apply PU spray adhesive

5. New thermal insulation

6. Adhered membrane 

Ready to Speak to An Expert about your Roof Refurbishment Project?

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