How many tiles per m² for each type?

Interlocking tiles require approximately 10-15 tiles per m² depending on the profile (e.g. Marley Modern 10/m², Redland Grovebury 10/m²). Plain tiles require approximately 60 tiles per m² at standard gauge (65mm headlap, 100mm gauge). This massive difference in quantity affects installation speed, labour cost, batten requirements and structural load.

Which is cheaper for a complete roof?

Interlocking tiles are significantly cheaper overall. Material cost is roughly £25-40/m² for interlocking vs £40-70/m² for machine-made plain tiles (or £80-150/m² for handmade clay plains). Labour is also much less — interlocking tiles cover the roof 4-5 times faster. A typical 100 m² roof costs £4,000-6,000 with interlocking tiles vs £7,000-12,000 with plain tiles.

What minimum roof pitch does each type need?

Interlocking concrete tiles typically require a minimum pitch of 17.5-22.5° depending on the profile and exposure. Plain tiles require a minimum pitch of 35° (or 30° with enhanced headlap). This means plain tiles cannot be used on lower-pitched roofs. Interlocking tiles are the only option for many modern roof designs with shallow pitches.

Which tile type is heavier?

Plain tiles create a heavier roof covering. Despite each individual tile being lighter, the sheer quantity means a plain tile roof weighs approximately 65-75 kg/m², compared to 43-55 kg/m² for interlocking concrete tiles. This affects rafter and truss sizing — always check that the roof structure is designed for the tile weight you choose.

This is subjective, but plain tiles are widely considered more attractive, especially on traditional and period properties. Their smaller size creates a finer texture with attractive coursing lines. Handmade clay plain tiles with their slight colour and shape variation are the premium aesthetic choice. Interlocking tiles look more uniform and modern — some profiles like Redland Rosemary or Marley Edgemere attempt to bridge the aesthetic gap.

Interlocking vs Plain Roof Tiles — UK

Compare interlocking concrete/clay roof tiles with plain tiles for UK roofing projects, covering coverage rates, weight, cost, wind resistance and aesthetics.

Side-by-Side Comparison

Feature	Interlocking Tiles	Plain Tiles
Tiles per m²	10-15	~60
Material cost per m²	£25-40	£40-150
Weight per m²	43-55 kg	65-75 kg
Minimum pitch	17.5-22.5°	35° (30° enhanced)
Installation speed	Fast — large tiles	Slow — many small tiles
Wind resistance	Good — mechanical interlock	Good — double lap + nailing
Aesthetics	Modern, uniform	Traditional, fine texture
Battens required	Wider spacing (~340mm)	Close spacing (~100mm)

When to Choose Interlocking Tiles

Budget-conscious re-roofs and new builds
Low-pitch roofs (below 35°)
Modern architectural styles
Large roof areas where cost saving is significant
Where planning allows modern tile profiles

When to Choose Plain Tiles

Conservation areas or listed building constraints
Traditional or period property aesthetics
Steep-pitched roofs (35°+) where they look best
Complex roof geometry with many hips and valleys
Premium appearance is the priority over cost

Related Calculators

Use the Roof Tile Calculator to calculate tile quantities and costs for your chosen tile type.

How We Calculate This

Frequently Asked Questions

Last updated: April 2026

All calculations are estimates. Verify with your supplier.

Interlocking vs Plain Roof Tiles — UK

Side-by-Side Comparison

When to Choose Interlocking Tiles

When to Choose Plain Tiles

Related Calculators

How We Calculate This

Frequently Asked Questions

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