Things You'll Need
Scrap strips of batten
Tiling battens are strips of squared wood that run the length of the roof to form lines, parallel to the eaves, from which the tiles are hung. Modern battens evolved from rough coppiced saplings around which thatch could be attached, and it was only with the advent of industrial wood cutting that they started to be produced with straight sides. Because battens support the tiles, the spacing is determined by the size of the tiles and the length of the roof to be covered.
Rest a sample tile on the roof so the bottom edge overhangs the fascia and guttering by the distance recommended by the tile manufacturer, taking into account any local ordinances that apply to your building. A general rule is for the bottom edge of the tile to stop just short of the center of the gutter. For example, with a 6-inch wide gutter, the tile would overhang by roughly 3 inches. Slide a strip of batten under the tile so that the tile hangs from it, and then fix the batten into place using a suitable hammer and nails.
Measure the overall length of the tile, and record the result. Measure the length of the tile nib (the raised section on the rear of the tile that rests on the batten) from the top of the tile to the bottom of the nib. Record the distance.
Deduct the length of the gutter overhang and the length of the nib from the length of the tile. For example, if the tile has a length of 16 inches, the overhang is 3 inches and the nib is 1 inch, the result is 12 because 16 - 3 - 1 = 12. This is the distance to the next batten.
Use a hammer and nails to attach a second short strip of batten further up the roof, the distance between it and the first batten being the distance calculated in Step 3.
Hold a final short strip of batten across the top of the roof, just below the ridge, and rest a tile on it. The batten should be positioned so that a ridge tile will overlap the roof tile by roughly 3 inches. Use a hammer and nails to fix the batten in place when the position is correct.
Measure the distance from the top of the lowest batten to the top of the highest batten. Divide the distance by the maximum gauge of the tiles being used, and round the result up to the next largest whole number. The result is the number of courses of tile on the roof, rounded to a whole number. For example, if the distance between the tops of the lower and upper battens is 204 inches and the maximum gauge of the tiles is 13 inches, then the number of courses and strips of batten is 16 because 204 / 13 = 15.6.
Divide the distance between the two battens by the result from Step 6. The result is the distance required between the battens. To conclude the example, 204 / 16 = 12.75, so the battens should be spaced 12.75 inches apart.
Gutter overhang is important to ensure that water from the roof flows into the center of the gutter rather than overshooting or running down the wall.
Take appropriate safety precautions when working on a roof. A fall could be fatal.