by bri-w »
Wed Nov 14, 2007 3:47 pm
If you're using natural slate or imitation slate (not interlocking) the principal is the same in that you always have a minimum of 2 layers with 3 layers at overlaps. The spacing of the battens (gauge) is calculated by deducting the overlap (usually 75 to 100mm) from the length of the slate then dividing by 2. You will need an extra shorter course top & bottom to maintain the double thickness.
Have fun!