Slate Coverage, Roof Pitch & Lap

Use the Slate Coverage charts to assist in calculating your required slate quantity. The tables below show Slate coverage by number per m²

Please click on one of the lap sizes below to view the table guide

50 - 85mm lap

Size – Nominal (mm)	50mm Lap	65mm Lap	75mm Lap	80mm Lap	85mm Lap
600 x 300	11.9	12.3	12.5	12.6	12.7
500 x 300	14.6	15.1	15.4	15.6	15.8
500 x 250	17.4	18.0	18.5	18.7	18.9
460 x 225	16.4	17.0	17.5	17.7	18.0
400 x 250	22.4	23.4	24.1	24.5	24.9
400 x 200	27.9	29.1	30.1	30.5	31.0
350 x 250	26.1	27.5	28.5	29.0	29.6
350 x 200	32.5	34.2	35.5	36.1	36.8
300 x 200	39.0	41.5	43.4	44.3	45.4

90 - 110mm lap

Size – Nominal (mm)	90mm Lap	95mm Lap	100mm Lap	105mm Lap	110mm Lap
600 x 300	12.9	13.0	13.1	13.2	13.4
500 x 300	16	16.2	16.4	16.6	16.8
500 x 250	19.1	19.4	19.6	19.9	20.1
460 x 225	18.2	18.5	18.7	19.0	19.3
400 x 250	25.3	25.7	26.1	26.6	27.0
400 x 200	31.5	32.0	32.5	33.1	33.6
350 x 250	30.2	30.9	31.4	32.7	32.7
350 x 200	37.5	38.3	39.0	39.8	40.7
300 x 200	46.5	47.6	48.8	–	–

115 - 135mm lap

Size – Nominal (mm)	115mm Lap	120mm Lap	125mm Lap	130mm Lap	135mm Lap
600 x 300	13.4	13.5	13.8	14.0	14.1
500 x 300	17	17.3	17.5	17.7	18.0
500 x 250	20.4	20.6	20.9	21.2	21.5
460 x 225	19.6	19.9	20.2	20.5	20.8
400 x 250	27.5	28.0	28.5	29.0	–
400 x 200	34.2	34.8	35.5	36.1	–
350 x 250	33.4	–	–	–	–
350 x 200	41.5	–	–	–	–
300 x 200	–	–	–	–	–

140 - 155mm lap

Size – Nominal (mm)	140mm Lap	145mm Lap	150mm Lap	155mm Lap
600 x 300	14.3	14.4	14.6	14.7
500 x 300	18.2	18.5	18.7	19.0
500 x 250	21.8	22.1	22.4	22.7
460 x 225	21.2	21.9	21.9	–
400 x 250	–	–	–	–
400 x 200	–	–	–	–
350 x 250	–	–	–	–
350 x 200	–	–	–	–
300 x 200	–	–	–	–

What does all this mean?

The actual cost of a roof per unit floor area of the building is determined by a number of factors, including roof pitch, slate size and head lap. By taking advantage of the various sizes and types of SlateScape roofing slate, considerable cost savings can be made.

Roof Pitch & Lap

The shallower the roof pitch, the smaller the area of the roof slopes. This area reduction, however, does not automatically lead to a cost reduction because lower pitches require larger slates and laps. The full cost advantage can be taken by adjusting the lap to the minimum required, for the pitch of the roof.