Important notes on slate fixing

Slate Selection

• CUPA's slates, once removed from their pallets need to be graded and sorted according to thickness. If slates are holed on site, the grading of the slates can be completed either before or after the holing process.
• With the exception of heavies, that require grading into four separate thickness, all other slates should be sorted into three separate thickness.
• During the grading phase, it is important to tap each slate to confirm its soundness. This simple test helps detect possible flaws before fixing.
• Only when all the slates have been graded and checked for imperfections should the fixing process begin.

Fixing

• It is important to use the thickest slates at the bottom of the roof, followed by slates of a medium thicknesses in the middle, reserving the thinnest slates for the top of the roof.
• If the roof pitch is less than 30°, or the building is single story, then additional care and attention is required as the visibility of thicker slates increases in these conditions.

Holing

• The slate nail should be located approximately 20mm–25mm from the edge of the slate.
• The nail hole should be made from the bottom of the slate.
• Holes can be made by machine or hand.

Notes

Detailed information on slate fixing and specifications can be found in BS 5534: 1997, BS 8000: Part 6 or ICP2:2002. CUPA Natural Slate also provides a detailed slating reference manual.

Slate Fixing Guides (pdf)