Roofing battens are nailed into the rafters or roof joists or trusses and provide support for the roof tiles or slates.
Slate roof batten spacing.
The top part of each slate is covered by two slates the centre of the slate of the next row and the lower part of the slate above that.
Recommended timber batten sizes for natural slate roofs are 50 25 mm up to 600 mm rafter spans according to bs 5534.
Batten gauge can sometimes be altered however to adjust headlaps or change the spacing between slate courses so the top area of visible slates on a roof look neat.
It also allows you to determine the holing gauge distance from hole to tail of slate and the number of linear metres of batten per m 2 of roof.
Set out the first second and all the rest of slates on a pitched roof.
Holing gauge mm battening gauge mm m batten per m2.
Holing gauge mm battening gauge mm m batten per m2.
The basics the slate or tile manufacturer or supplier will specify the size of battens to be used typically this would be 40 x 20mm 1 5 x inch but where the horizontal gaps between rafters is large or the slates tiles are heavy then bigger battens may be needed.
Gauge length of slate lap 2 battens should be nailed at maximum 600 mm.
The most commonly used slate size in southern england is 500x250mm and 400x250mm in scotland and the north of england.
Slates are laid on the battens in a brick bond pattern i e.
For example 25 x 50mm battens are required for single lap modern roof tiles laid on rafters with a 600mm span.
Battens should be set out horizontally across the roof at a gauge calculated from the formula.
Nail the first full course of slates to the second batten so that the tail rivet passes between the two second under eaves slates and protrudes through the hole in the tail of the full slate.
Batten gauge length of slate headlap 2.
Ensure the first full course of slates oversails the gutter by 50 55mm.
This layout gives a double lap covering i e.
Slate length mm battening gauge mm m batten per m2.
The updated bs 5334 code of practice for slating and tiling specifies a number of batten sizes based upon the span of the rafters and the product being used.
The holing gauge can be calculated as.
Set out the first second and all the rest of slates on a pitched roof.
With the joints between them aligned with the centre of the slates above and below and with about 3mm between the sides.
The batten gauge can also be calculated using the formula.
This is normally done by adding another batten which reduces batten gauge and increases headlap or by stretching which is increasing batten gauge slightly.