Christchurch Girls High School

Related Systems: Ultratherm Xtreme
Architect: Jasmax
Project Date: March 2018
Location: Christchruch

As part of a larger seismic upgrade project to the existing Administration Building at Christchurch Girls High School, the existing roof needed to be re-designed and re-built.  A new plywood diagram was required which was used as the structural substrate for the new RoofLogic insulated roof assembly.


RoofLogic specified the Ultratherm Xtreme system with Derbigum membrane for the project. Designed to perform as a diaphragm, the new plywood roof structure was installed without fall.  The RoofLogic system introduced the required falls with the use of tapered insulation board.

The RoofLogic system was installed over structural plywood and incorporated:

  • RL Vapour Control Layer
  • RL HD Tapered Insulation
  • RL Roof Board HD
  • Derbigum Membrane
SYSTEM benefits
  • Required falls could be achieved within the insulation layer not within the structure.
  • Full hygrothermal calculations were provided to ensure that there was no long term condensation risk with the new assembly, especially in respect to the plywood diaphragm and sub-framing.
  • Full structural calculations provided, with PS1 issued for structural design.
  • RL Roof Board (HD) included in build-up for increased trafficability/durability.
  • Use of premium quality Derbigum membrane with proven 40 year durability.