Category: Roofing Guides
Tags: slate cutting, tile cutting, DIY roofing, roofing basics
What You’ll Learn
Cutting roof tiles is a skill every roofer needs. This guide explains:
- The tools you can use
- How to cut tiles safely
- How to cut slate, concrete & clay
- Mistakes to avoid
- When you shouldn’t cut tiles
Tools You’ll Need
Manual Tools
- Slate guillotine
- Slate cutter / slasher
- Nibblers
- Chalk line
- Roofing square
Power Tools
- Grinder with diamond blade
- Wet tile saw (optional)
- Multi-tool for trimming tight spaces
Safety Gear
- Gloves
- Eye protection
- Dust mask
- Ear protection when using grinders
How to Cut Slate Roof Tiles (Step-by-Step)
1. Mark Your Cut
Use:
- A ruler
- Roofing square
- Chalk pencil on the slate surface
Make sure your line is straight and centered.
2. Score the Slate
If using a slate cutter:
- Place the blade directly on the line
- Apply firm downward pressure
- Score the slate once or twice
This weakens the slate so it splits cleanly.
3. Snap the Slate
Hold the slate with two hands and:
- Apply pressure opposite the score line
- Snap cleanly downward
If done right, this creates a smooth natural edge.
4. Trim the Edges (Optional)
Use slate nibblers to:
- Smooth rough corners
- Create fitting shapes around valleys, vents, or windows
How to Cut Concrete or Clay Tiles
1. Mark Your Cut
Use chalk or pencil.
Always mark on the front of the tile.
2. Use a Grinder With a Diamond Blade
Hold the grinder:
- Two hands
- Firm grip
- 45° angle
Cut slowly and let the blade do the work.
3. Support the Tile
Place the tile on:
- A rubber mat
- A piece of timber
- Grass or a soft surface
This reduces vibration and prevents cracking.
4. Smooth the Edge
If needed, lightly grind the sharp edge.
Common Mistakes to Avoid
❌ Cutting too fast — leads to chipping
❌ Not supporting the tile when cutting
❌ Using worn-out blades
❌ Not wearing PPE
❌ Cutting tiles in the wrong direction (especially concrete)
❌ Forgetting dust suppression when using grinders
Pro Roofer Tips
- For slate valleys, always cut slightly oversized and trim for perfect fit.
- When cutting wet tiles, let them dry before fixing.
- Keep spare blades — concrete ruins them fast.
- If a tile has internal cracks, don’t cut it. Replace it.
FAQ
What’s the easiest method for beginners?
Using a slate cutter or guillotine — safe and clean.
Can you cut roof tiles with a handsaw?
Clay and concrete: no. Slate: you can score and snap, but a cutter is faster.
Why do my tiles keep snapping wrong?
Usually because:
- You’re scoring too lightly
- The tile isn’t supported
- You’re using a dull blade