Duo / Plus roof

Plus roofs built with JACKODUR thermal insulation are used to refurbish buildings when the existing roof structures cannot be removed.

The so-called "plus roof" is a gravelled inverted roof in which a further layer of thermal insulation and a gravel layer are added to a standard warm-roof structure. This approach is particularly recommended for energy-saving roof renovations when the roof membrane is still intact, for instance.

With conventional warm-roof renovation, the intact roof membrane is destroyed, the thermal insulation below it is improved and a new roof membrane must be installed. In contrast, with a plus roof, the existing warm-roof structure is preserved, and an additional inverted-roof system is simply laid on top of it. Positive side effect: the existing intact roof membrane is not destroyed but preserved, and at the same time it is protected against the damaging effects of UV radiation or freeze-thaw cycles through the additional new thermal insulation. This increases its service life by several years. Should the membrane still become defective at some point, the inverted roof can simply be "moved aside", the membrane replaced or repaired, and the existing inverted roof re-laid.

  • Practical example of a duo or plus roof
  • 1. Interior plaster 2. Reinforced concrete surface 3. Bituminous vapour barrier 4. Existing thermal insulation 5. Double layer of waterproofing, first layer with a cold-glue self-adhesive sheet 6. JACKODUR KF 300 Standard SF 7. JACKODUR filter layer WA 8. Layer of gravel

For more information on inverted roofs, please go to our website at www.umkehrdach.com


  • with an intact roof membrane: cost-effective method for the energy-saving renovation of an existing roof structure
  • with damaged waterproofing: thermal insulation can be laid quickly and easily on the new waterproofing – the old warm-roof structure is preserved
  • in either case: waterproofing is protected from the weather and its service life consequently significantly extended
This website uses cookies in order to guarantee the best possible service. With your visit to www.jackon-insulation.co.uk, you agree to our use of cookies.