Double Roman   Technical data


Tile size (overall):
420 x 332 mm

Nominal tile mass:
4,5 kg

Nominal linear cover:
301 mm
at lock mid-shuttle position





The side interlock provides for a practical 2 mm play between the tiles (± 1 mm either way of the nominal cover) which gives flexibility when setting out the roof and helps to acheive the correct perpendicular alignment of the courses.

Minimum roof pitch with 100 mm tile headlap 17,5°
Minimum roof pitch with 75 mm tile headlap 26°
Rafter/Trusses (As per structural requirements)
Rafters centres
760 mm with 38 x 38 mm batten
900 mm with 38 x 50 mm batten fixed flat
1000 mm with 38 x 50 batten on edge
Note: Above 760 mm the rafter spacing can be increased only with engineer-designed trusses and with 38 mm x 50 mm batten of the correct grade. All structural timber to comply with SABS 653, 653 and 1245.
Underlay A suitable underlay is in all cases recommended. Modern practice has demonstrated that the underlay is a fundamental part of a tiled roof at pitches below 26° and for pitches above 45°, and at all pitches in exposed and coastal areas.
Tiling data at pitches of 17,5° to 25°
Minimum tile headlap 100 mm
Maximum batten centres 320 mm
Batten per m2 (net length) 3,13 m
Tiles per m2 (net) 10,38
Mass of tiles per m2 ± 46,7 kg
Tiling data at pitches of 26° and above
Minimum tile headlap 75 mm
Maximum batten centres 345 mm
Batten per m2 (net length) 2,9 m
Tiles per m2 (net) 9,63
Mass of tiles per m2 ± 43,4 kg
Distance from top edge of first batten
to outside edge of fascia board
335 mm
Distance from top edge of top batten to rafter apex 25 mm

All tiling and fixing to comply with SABS 062 : 1991 Code of Practice, with Marley standard fixing specifications and with Marley Health and Safety instruction.