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.
How to felt and batten a slate roof.
What roof pitch do i need for what slate size generally speaking 20 degrees is the lowest advisable pitch for a slate roof depending on the size of the slates and how much that the roof is exposed to.
The holing gauge can be calculated as.
This is not required for dry fix systems.
Joints should be directly over rafters with the batten square cut tightly butted and skewed nails.
Batten gauge length of slate headlap 2.
Start at the lower edge of the roof and position the first batten so that the slates tiles give the required overhang over the fascia set the distance at both ends of the roof and run a string line between check along the line to make sure that the distance is fairly consistent and satisfactory fascia boards may sometimes wonder a little bit but this can be checked by eye looking along the front face.
Holing gauge batten gauge headlap 10mm.
Roof battens and gauge the gauge is the space between the roof battens this will set the overlap of your chosen slate in most cases.
The batten gauge can also be calculated using the formula.
Underlay is generally held in place by the tile battens but where nailing is required nails should be extra large head felt nails of 3 35 mm shank diameter and 20 mm long.
If a batten end is to be set in mortar be sure an appropriate treatment has been applied.
Lay the underlay starting at and parallel to the eaves maintaining a consistent tautness.