Exxon Mobile

Ampteam Limited, were asked to provide a UNIFOLD® scheme for the conversion of level gutters, serving the central roof area of the building, to falls conditions, with a brief to eliminate standing water and leaks which had plagued the building for some time.

Some 900 metres of valley gutters serving four separate Atrium roof areas in banks of six, which in turn are served by 5 metre wide valley gutter sections serving as Access and escape link bridges, were requested to be converted from level to laid to falls.

Lower valley gutter bounding the periphery of the roof area serve and discharge the main roof area via 5 metre wide chutes from the escape link bridges. Positioned in the less sensitive areas, these were allowed to be laid level, although their existing holding capacity has been improved.

The existing roof and gutter areas had initially received a PVC membrane when built. This, however, was patched in many areas and showing signs of deterioration. There were many concerns about the continued longevity of this installation.

UNIFOLD® Gutter Lining System was chosen for its versatility, unfailing ability to replicate existing systems, provide falls conditions in level gutters and its long life. The system is also guaranteed for 20 years.

Tapered Cork insulation was chosen to provide the base for the gutters and this was supplied in cut sets. The fall ratio was based on a minimum of 1:150. The Unifold gutters were purpose made to suit the falls ratio and provided in numbered sets to suit the individual gutters.

Full site information was provided including schemes of falls, laying sequences and special details and instructions. In all, more than 50 separate drawings were issued to site.

In accordance with Ampteam policy, all fabrication was factory manufactured and sealed prior to delivery to site. This ensures complete installation quality and integrity.

The valley gutters serving the central Glazed Atrium roof areas were installed first. These comprised an apex at the central position of the gutters with falls arranged down to discharge ends at the Escape Link Bridges.

As the glazed Atrium roof was above a sensitive area, no weekday work was allowed.

Friday deliveries were permitted but all work was conducted during weekends.

The end Atrium Roof area valley gutters were single fall from a transverse gutter at the outer perimeter edge.

Access into the transverse gutter was extremely tight and normal joints could not be made so sections of UNIFOLD® were supplied to span individual Atrium ends and joins were made at the junctions with the valley gutters via factory manufactured tees, using UNIFOLD® patented clip joints.

The existing transverse gutters were already higher than the valley gutters to aid discharge, but in order to create the necessary falls the UNIFOLD® transverse liner was lifted sufficiently to provide the required falls for the valley gutters.

There was space to achieve this condition without compromising the capacity of the original transverse gutters.