Final answer:
The typical minimum headlap for tile is 2 inches.
Step-by-step explanation:
The typical minimum headlap for tile is usually 2 inches.
Headlap is the amount by which a tile/slate overlaps the course below it. Margin – This is the visible or exposed area of a slate from the bottom or ' tail ' of one slate up to the point the slate above overlaps it.
For pitched roofs, the head-lap specification in BS 5534 recommends 65mm minimum and the maximum gauge of battens should be 100mm. Gauges of less than 88mm are not recommended. The sidelap should be not less than one third the width of the tile, typically 55mm.
This will depend on the manufacturer. For a standard pitched roof, however, tiles are recommended to be placed on at least a 30-35°. Anything lower would be considered a low-pitched roof which will require a different approach.
The minimum slope allowed for tiles is 2½:12. A double underlayment must be provided when the slope is between 2½:12 inches and 4:12. Tile roofs that are steeper than 4:12 only require one layer of underlayment.