Client - MOE Awatapu College Palmerston North
Architectural Design - Paul Patel & Associates
Main Contractor - Maycroft Construction
Applicator - McCreery Roofing Limited
Installed for the school’s opening in 1976, the original roofing was well past its warrantable life span after 44 years. The classrooms endured roof leaks at the ridge line, flashings around roof lights and at roof penetrations. The roof profile had also been manufactured with panning in the tray sections allowing water to pond which lead to the roof rusting out in many areas. Roof expansion during the hot summer months caused rivets to shear and silicone sealant to fail allowing water ingress. After many repairs, a decision was made to re-roof the entire block.
Long length manufacture. With increased gauge thickness and high strength metal, these roofs are suited for wide span fixing and will dent or crease if not walked across carefully, causing ponding and fracturing to the finished paint coating.
Thermal shock. Occurring after lengthy periods of sun followed by quick cooling due to cloud coverage and instant re-exposure to sun, this causes mechanical fixing penetrations to elongate. Thermal shock has a similar effect on rivets and sealants at all penetrations. With a very detailed, low slope metal roof there is a high reliance on rivets and sealants which can become a watertightness risk.
duroTUF TPO (Thermo plastic polyolefin) is a specified waterproof solution for low slope roofs, providing a dry, warm environment for the pupils in the classroom. In comparison to alternative membrane systems, there were no end laps and very few side laps with the 30m x 30m installation rolls. This picture shows the benefits of the duroTUF TPO system.
Best practice is always the removal of the existing metal roof, where external gutter is to remain. The increase in roof height can cause heavy rainwater runoff, spilling over the external gutter system directly onto people below. Another benefit is installation of new cabling. The existing thermal insulation blanket can also be checked and increased in thickness if required.
duroTUF TPO membrane system provides a seamless smooth surface for water runoff. All the accessories are fully compatible TPO items, thermally welded to the primary duroTUF TPO membrane system. The membrane system is firm under foot with duroTUF walkway rolls available for servicemen to walk on providing full protection to the membrane system. duroTUF TPO is independently BRANZ appraised and the installations are by approved and licenced Waterproofing Systems applicators who are required to complete quality control sheets as the work progresses, available on our mobile APP or by contacting us on ph: 5791460.