How many ridge tiles do I need per metre?

Ridge tiles are standard 450mm long, but with the required overlap (typically 75-100mm), the effective coverage is approximately 300mm per tile. This means you need around 3.3 ridge tiles per linear metre of ridge or hip. Always round up and add 5% wastage. For the main roof tiles, use our Roof Tile Calculator.

Should I use mortar bedding or a dry ridge system?

Since 2015, UK Building Regulations (BS 5534) require mechanical fixing for ridge and hip tiles on new builds and re-roofs. Dry ridge systems are now the standard as they provide superior wind resistance and do not crack like mortar over time. Traditional mortar bedding is still acceptable for repairs to existing mortar-bedded ridges.

What is a dry ridge kit and what does it include?

A dry ridge kit typically includes ridge tree bars (batten straps), unions to join the bars, roll-out ridge sealing strips and clips. Each kit covers approximately 6 metres of ridge. Brands like Manthorpe, Klober and Marley all produce compatible systems. They attach mechanically to the batten, providing a secure fixing without mortar.

How much mortar do I need for ridge tiles?

If using traditional mortar bedding, you will need approximately one 25kg bag of sand and cement mortar per 4-5 linear metres of ridge. Use a 1:3 cement to sharp sand mix. In practice, most roofers now use a dry ridge system as it is more durable and complies with current Building Regulations.

Do I need different ridge tiles for hips?

Hip tiles are often the same profile as ridge tiles (half-round or angular), but the hip end usually requires a special hip iron or hip end cap. Some systems use mono-pitch or bonnet hip tiles instead. Check with the tile manufacturer for the correct hip accessories for your specific tile range.

Ridge Tile Calculator — How Many Ridge Tiles and Dry Ridge Kits?

Ridge Tile Calculator — How Many Ridge Tiles Do I Need?

Calculate ridge tile quantities for ridges and hips. Includes mortar or dry ridge kit calculations for UK roofs.

Ridge Length

Total length along the top of the roof

Hip Length (if applicable)

Combined length of all hip edges

Ridge Tile Type

Fixing Method

Include wastage allowance

Adds 5% extra for breakages

Wastage Percentage

5% is typical for ridge tiles

Price Per Ridge Tile (optional)

Enter your supplier price for a cost estimate

How We Calculate This

Our ridge tile calculator determines the number of ridge tiles needed based on the total length of ridge and hip lines, accounting for the standard overlap between tiles. It also calculates mortar or dry ridge kit requirements depending on your chosen fixing method.

The formula

Ridge tiles = Total length (m) ÷ 0.3m (effective cover per tile) × Wastage factor

Standard ridge tiles are 450mm long. With a 75-100mm overlap at each joint, the effective coverage is approximately 300mm per tile.

Fixing methods

Dry ridge system: Mechanically fixed, compliant with BS 5534. One kit covers ~6m.
Mortar bedding: Traditional method, ~1 bag per 4-5m of ridge. Now mainly used for repairs.

Since 2015, BS 5534 requires all ridge, hip and verge tiles to be mechanically fixed on new-build and re-roofing projects. Dry ridge systems are the recommended standard for UK roofs, offering better wind resistance and longevity.

Frequently Asked Questions

Last updated: February 2026

All calculations are estimates. Verify with your supplier.

Ridge Tile Calculator — How Many Ridge Tiles Do I Need?

How We Calculate This

The formula

Fixing methods

Frequently Asked Questions

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