Preparation
All work on beam fillings, fascia boards, guttering, flashings and parapets, etc., should be completed before tiling commences.

Rafters/trusses
To comply with SABS 563 Softwood structural timber.

Underlay
Underlay must be SABS approved. The underlay must be fixed horizontally between rafters and battens with 150mm minimum overlaps and carried well into the gutters. Avoid allowing the underlay to sag and form water traps - particularly behind fascia boards.

A strip of underlay, at least 600mm wide, must be placed at hips so as to overlap each side for its full length. A similar strip must be laid for the full length of each valley ensuring that the opposing slopes overlap the edges. All underlay is to be nailed to the rafters with a minimum of non-corrodible clout nails.

Battens
To comply with SABS 653 Softwood battens and brandering. Batten joints must meet halfway across the top face of a rafter.

Tiling
Tiles are to be laid “straight-bond” in even courses. The Monier Elite profile is the only exception to this rule and must be laid “broken-bond”.

Batten gauges
>26 degrees -------------- not to exceed 345mm
<26 degrees -------------- not to exceed 320mm

Always ensure that the battens are spaced equidistant from each other by correctly setting out the roof prior to commencing the tiling. It is bad practice to cut tiles to fit the apex course.

Eaves
The bottom edge of the first course of tiles must overhang the fascia board sufficiently to allow rain water to discharge efficiently into the gutter, and must be elevated to bring the eaves course into the same plane as the following courses. Where eaves filler units are used, these should be fixed simultaneously.

Verges
Verges must have equal overhangs at each end of the roof and should be finished with purpose-made verge tiles.

Tile rows
In most instances rows can be laid without cutting
tiles. When cut tiles are required to complete a row, always ensure that the surface area of each cut tile exceeds half the tile area. Two cut tiles containing the nail hole provide a superior finish to a row, rather than a single quarter tile at the end of a row without any provision for fixing. Tiles must be laid loose and not tight against each other to allow for thermal movement.

Valleys
Open valley: a non-corrodible valley gutter at least 200mm wide should be constructed between two counterbattens. The tiles on each side of the valley should be neatly cut to alignment to project over the side welt by at least 50mm. The cut tiles should be supported and well fixed to the timber.

Closed valley: as above, except that the tiles should be cut in a manner to allow a neat butt-joint at the valley centre.

Abutments
An adequate flashing material should be used to seal the junctions at the abutments. Where concealed gutters are necessary, the tiles should be neatly cut to approximately 40mm from the abutment. In all other instances, tiles should be cut to fit as close as is practical to abutments.

An apron flashing must be used where the roof slope falls below the abutment. Conversely, where the slope falls above the abutment, back-gutters must be installed.

Mechanical fixing
Tiles are to be nailed and/or clipped to resist wind uplift in accordance with the existing SABS Codes of Practice and the manufacturer’s recommendations. At roof perimeters, abutments and intersections, the overhanging or abutting tiles plus two tiles in from that tile shall be fixed. When in doubt about the recommended fixing specifications for your area, always consult Lafarge Roofing.

Mortar
All bedding mortar is to consist of 3 parts coarse graded sand to 1 part Portland cement, suitably pigmented to match the colour of the tiles. All butt-joints are to be solid bedded.