The maximum recommended support spacings are based on testing in accordance with AS 1562.1:1992, design and installation of sheet roof and wall cladding, and AS 4040.1:1992, resistance to concentrated loads.

Depending on support spacings used, flatdek can be installed as either:

• light foot traffic roof (one maintenance person walking on roof); or
• no foot traffic roof (will not support the weight of a person walking on it), see tables below.

The pressure considered is based on a typical flat awning attached to an enclosed structure. The pressure coefficient for this situation is based on 3 sides blocked.

The tables are based on flatdek fixed to supports of 1.5mm BMT minimum. For FLATDEK 310 awning applications, the strength of the receiver channel method of attachment must be considered in the design of any system. An alternative method is to use a rear gutter attachment all round for greater weather-tightness.

* When dead load deflections need to be considered in designs, use the tabulated values. Where the higher deflections can be tolerated, then the spans can be increased to 4800mm for single spans for N1 to N3; 5000 or end & internal spans for N1 to N3.

NOTE: For pitched structures when dead load deflections need consideration, use a maximum span of 3300.