Conventional Slate Roofing

Specifications:

Pitch: Recommended minimum 30°

Slates: Various lengths (see below) with widths 205mm, 225mm, 280mm. Holed for center nailing, with 2 holes DRILLED NOT PUNCHED.

Colour: Silver Blue, West Country or Multi Colour.

Nails: 50mm Length, 2.8mm Diameter,  galvanized serrated clout (inland) or copper serrated clout (coastal) nails.

Trussed Rafters: Free-standing rafters require correct calculation of size and spacing, based on an overall weight of slate roofing of approximately 78kg/m2. Any tables of size and spacing of free standing rafters should be considered as a guide only.

Battens: 38mm x 38mm (nominal). Laying of Battens is to be commenced at the eaves, allowing for the correct overhang of slate into the gutter, then continued upwards towards the ridge. See diagram overleaf for spacing details. Where slates are to be fixed directly onto timber boarding, the boarding shall be at least 25mm thick.

Laying: Slates are to be laid in double thickness, with a headlap of 75mm. Firstly an under-eave slate is nailed to the first (or tilting) batten, with the head of the slate resting on the second batten, and with a 50mm overhang into the gutter. Full slates are then centre-nailed to the second batten, and thereafter proceed upwards to the ridge. Slates are to be laid to straight lines horizontally and vertically, in broken bond.

Plumbing: All plumbing requirements are to be supplied by the builder. Laying of the slate roof will be delayed if a plumber is not made available, when requiested by Mazista, for supplying and cutting the necessary flat iron, flashings, etc. Wall soakers to measure 150mm across, with 75mm turn-up, and length equal to batten spacing (see diagram overleaf) plus 100mm.

ALL SPECIFICATIONS ARE SUBJECT TO CHANGE WITHOUT NOTICE.

Construction Detail:

Top of Fascia Board to be 13mm higher than top of second batten, to allow as tilting batten.
Top of Ridge Batten to be 20mm above level of other battens.

Note 1:
Where Fascia board is not required, tilting batten 50mm x 38mm should be used instead.

Note 2:
Batten Spacings: (Dependent on length of slates used)

Slate Length x y z
305mm 160mm 115mm not more than 115mm
355mm 185mm 140mm not more than 140mm
405mm 210mm 165mm not more than 165mm

x is measured from outside of fascia board on top edge of batten.
y and z are measured from top edge to top edge. See diagram.

Note 3:
If a mitred hip or mitred valley is required, the battens must be firmly joined in a true mitre along the centre line of the valley or hip rafter, as applicable.

THE ABOVE INFORMATION IS TO SERVE AS A GUIDE ONLY