Once the number of square meters of the roof is known, the next step is to calculate how many slates you will need
How many slates per square metre (m2)?
This table shows the required number of slates per square metre for effective coverage.
The number of roof slates that are needed depends on the spanish slate size and the headlap in mm.
For example; If we are using a 600 x 300mm slate (24″ x 12″) with a headlap of 90 mm we would need 13 slates tiles per m2.
Quantity of Slates | ||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|
Slate Size | Lap mm | |||||||||||
(Nominal) mm | 50 | 65 | 75 | 80 | 90 | 100 | 110 | 115 | 120 | 130 | 140 | 150 |
600 x 300 | 12.1 | 12.5 | 12.7 | 12.8 | 13.1 | 13.3 | 13.6 | 13.7 | 13.9 | 14.2 | 14.5 | 14.8 |
500 x 300 | 14.8 | 15.3 | 15.7 | 15.9 | 16.3 | 16.7 | 17.1 | 17.3 | 17.5 | 18.0 | 18.5 | 19.0 |
500 x 250 | 17.8 | 18.4 | 18.8 | 19.0 | 19.5 | 20.0 | 20.5 | 20.8 | 21.0 | 21.6 | 22.2 | |
450 x 300 | 16.7 | 17.3 | 17.8 | 18.0 | 18.5 | 19.0 | 19.6 | 19.9 | 20.2 | 20.8 | 21.5 | |
400 x 250 | 20.2 | 20.8 | 21.3 | 21.6 | 22.2 | 22.9 | 23.5 | 23.9 | 24.2 | 25.0 | 25.8 | |
450 x 230 | 21.7 | 22.6 | 23.2 | 23.5 | 24.2 | 24.8 | 25.6 | 26.0 | 26.3 | 27.2 | 28.1 | |
400 x 300 | 19.0 | 19.9 | 20.5 | 20.8 | 21.5 | 22.2 | 23.0 | 23.4 | 23.8 | |||
400 x 250 | 22.9 | 23.9 | 24.6 | 25.0 | 25.8 | 26.7 | 27.6 | 28.1 | 28.6 | |||
400 x 200 | 28.6 | 29.9 | 30.8 | 31.3 | 32.3 | 33.3 | 34.5 | 35.1 | 35.7 | |||
350 x 300 | 22.2 | 23.4 | 24.2 | 24.7 | 25.6 | 26.7 | 27.8 | |||||
350 x 250 | 26.7 | 28.1 | 29.1 | 29.6 | 30.8 | 32.0 | 33.3 | |||||
350 x 200 | 33.3 | 35.1 | 36.4 | 37.0 | 38.5 | 40.0 | 41.7 | |||||
320 x 220 | 33.7 | 35.7 | 37.1 | 37.9 | 39.5 | 41.3 | 43.3 | |||||
320 x 180 | 41.2 | 43.6 | 45.4 | 46.3 | 48.3 | 50.5 | 53.0 | |||||
300 x 200 | 40.0 | 42.6 | 44.4 | 45.5 | 47.6 | 50.0 | ||||||
300 x 150 | 53.3 | 56.7 | 59.3 | 60.6 | 63.5 | 66.7 |