Ridge Tiles: Profiles, Fixing Methods and What Your Roofer Should Be Doing

A loose ridge tile lets water into the roof space. Not a dramatic flood, just a slow drip down the underside of the tile and onto the felt, pooling at a rafter joint where nobody looks until the plasterboard ceiling below starts to stain. By the time you notice, you've got damp insulation, potential timber decay, and a repair bill ten times what a properly fixed ridge tile costs. On a new extension, getting the ridge wrong means a building control failure. On an existing roof, it means the most common maintenance job roofers get called out for. Either way, understanding what ridge tiles are and how they should be fixed saves money.

What they are and what they're for

Ridge tiles are the shaped caps that sit along the apex of a pitched roof, covering the gap where two roof slopes meet. Without them, rain, wind, and birds have a direct route into the roof space. They're the last roofing element to go on (every tile course must reach the top before the ridge is fixed) and the first thing that fails if installed badly.

They're made from the same material as your main roof tiles. Concrete ridge tiles go on concrete tile roofs. Clay ridge tiles go on clay tile roofs. Mixing materials is a mistake: concrete and clay weather at different rates, producing an obvious colour mismatch within five years, and the profiles won't seat properly against each other.

The standard UK length for a concrete ridge tile is 450mm. Clay ridge tiles vary: 300mm is standard for traditional handmade clay (Dreadnought, for example), while some continental ranges run 330 to 500mm. This length matters when you're calculating quantities.

Ridge tiles weigh around 4 to 5kg each for concrete (a Redland half-round is 4.1kg per tile at 450mm). They're handled individually at height, so the weight is manageable but you're working on scaffolding at the highest point of the roof.

Types and profiles

The profile of the ridge tile must match the profile of your main roof tile. Get this wrong and you'll have gaps where water and wind get through, or the ridge tile won't sit flat. This is the single most common ordering mistake.

Click to enlarge

A quick decision guide: if you have standard interlocking concrete tiles (Marley Ludlow, Redland Grovebury, Sandtoft Double Roman), go with half-round. If you have flat interlocking tiles or concrete slates, go with angular. If you're unsure or dealing with an unusual pitch, universal angle is the safe choice because it adapts.

For clay tiles, always source ridges from the same manufacturer as the main tiles. Dreadnought's range includes angle, half-round, hogback, and mono ridge in Staffordshire blue and other colours. Mixing a Dreadnought ridge with a different clay manufacturer's tiles will produce a colour mismatch that gets worse over time.

Stop ends

At gable ends (where the ridge meets the edge of the roof), you need stop-end ridge tiles. These have a sealed end that closes off the ridge line. If your roofer uses a standard open-ended ridge tile at the gable, water blows in through the open end. It's a small detail that gets missed. Check for it.

Ventilated ridges

Most dry ridge systems include a built-in 5mm continuous ventilation gap at the apex. This isn't optional decoration. Cold roofs (where insulation sits at ceiling level, not between rafters) need this gap to ventilate the roof space and prevent condensation under BS 5250 and Approved Document C. The 5mm gap is specifically required for roofs with pitches above 35 degrees or spans exceeding 10 metres.

The good news: if you're specifying a dry ridge system (which you should be on any new extension), the ventilation is included automatically. One less thing to coordinate separately.

Dry ridge vs mortar bedding

This is the decision that confuses most homeowners, partly because the regulations say one thing and some roofers still do another.

What the regulations actually say

BS 5534:2014+A2:2018 requires all ridge and hip tiles to be mechanically fixed. Mortar alone is not sufficient. This applies to new builds, extensions, and (since the 2018 amendment) re-roofing work.

Dry ridge products must conform to BS 8612:2018, which tests for wind load resistance, rain and snow ingress, ventilation performance, and durability. Building control inspectors check for BS 8612 compliance on new extension roofs.

The heritage exception

Period properties and listed buildings are different. Traditional mortar bedding with no mechanical fixing is acceptable where the local conservation authority or building control agrees. This is explicitly acknowledged in BS 5534 and BS 8000-6. If you're re-roofing a Victorian house with decorative crested ridges, a dry ridge system may not accommodate the tile profile, and the visible foam filler strip will look wrong. Glidevale's Fulmetal Rediroll system is one product that works with decorative ridge tiles on older properties. A private building control inspector is often more pragmatic about heritage roofing than a local authority inspector.

The inconsistent enforcement problem

Forum threads are full of homeowners reporting that their local building control passed mortar-only ridge work on extensions, contradicting BS 5534. This happens. Some inspectors apply the standard rigorously; others don't. But the standard exists, and if a dispute arises later (insurance claim, property sale survey), mortar-only fixing on a post-2018 roof is documented non-compliance. Don't rely on an inspector's discretion. Specify compliant fixing and remove the risk.

In Scotland, dry ridge is mandatory for all new roofs (not just new builds), which is stricter than England and Wales.

How to work with ridge tiles

You won't be installing these yourself (it's scaffold-height work), but you need to know what your roofer should be doing and what to check.

Installation sequence for dry ridge

The ridge is the last thing to go on. All main tile courses must be laid to the top before ridge work starts. The sequence:

1. Breathable membrane is trimmed to leave a 30mm gap at the apex (for dry ridge; mortar bedding uses a 150mm overlap instead).
2. Ridge batten brackets are fixed to the rafters along the ridge line.
3. A ridge batten (typically 50 x 50mm) is secured to the brackets.
4. The top course of main tiles is completed.
5. The ventilated roll is laid centrally along the ridge with 100mm overlaps at joints.
6. Profile fillers (foam strips shaped to match the contour of the main tiles) are pressed down onto the top tile course.
7. Ridge tiles are placed and secured with mechanical clips screwed into the ridge batten at every joint.
8. Stop-end ridge tiles go on at gable ends.

Mortar bedding (where permitted)

For heritage or repair work where mortar bedding is agreed with building control, the mortar mix is 1:3 cement to sand with plasticiser (Marley recommends two parts building sand to one part sharp sand). Ridge tiles are bedded continuously at edges with tile slips at joints. Under current standards, each tile still needs a supplementary mechanical fixing (screw, clip, or wire) alongside the mortar.

The underlay overlaps 150mm across the apex for mortar bedding, rather than the 30mm trim-back used for dry ridge.

How much do you need

The calculation is straightforward. Measure the ridge length (the horizontal line where the two roof slopes meet at the apex). For a typical single-storey rear extension with a simple dual-pitch roof, this is usually the full width of the extension.

For 450mm concrete ridge tiles: divide the ridge length in metres by 0.45, round up to a whole number, then add 5% for breakage.

For 300mm clay ridge tiles: divide by 0.30 instead.

Worked example: a 6-metre ridge using 450mm concrete tiles. 6 / 0.45 = 13.3, rounded up to 14 tiles. Plus 5% breakage: 14.7, rounded up to 15 tiles. Order 15.

If your extension has a hip roof (where the roof slopes down to the walls at the sides as well as front and back), you'll also need hip tiles for the hip lines. Hip tiles are the same material and profile but fit along the diagonal hip line instead of the horizontal ridge. Measure each hip length separately and calculate the same way. The bottom hip tile is often secured with a hip iron on older roofs.

Cost and where to buy

Standard half-round concrete ridge tiles cost £5-10 at major UK retailers. That's for mainstream brands like Marley, Redland (BMI), or Sandtoft in standard colours. Redland offers 11 colour options across coated, smooth, granular, and sanded finishes. Expect to pay at the higher end for granular or coated finishes.

Security ridge tiles (interlocking, anti-theft) are a different price bracket entirely: £15 – £25 per tile. Unless you're in a high-crime area or on an exposed site where tiles could be lifted by extreme wind, standard ridge tiles are fine.

For a typical 6-metre extension ridge, that's 15 tiles at £5 – £10 each: £5 – £10 for the ridge tiles alone. Add a dry ridge kit for the mechanical fixing system and you're looking at £5 – £10 for materials. See the dry ridge system page for kit pricing by brand.

The tiles themselves are a small fraction of the total cost. Labour dominates ridge work because it's at height.

For a 6-metre ridge, that's £300 – £390 installed. For a semi-detached with hips as well as ridges, expect £300 – £390.

If you're getting a full re-roof or new extension roof, the ridge work is part of the tiling contract and shouldn't be quoted separately at these rates. These per-metre figures apply when ridge work is the only job.

Repointing is the budget option for existing mortar-bedded ridges that have cracked but aren't loose. At £200 – £300 per 10 metres, it's cheap compared to a full dry ridge upgrade, but you'll be paying again in 10 to 15 years. If your roof is already being scaffolded for other work, upgrading to dry ridge at the same time makes financial sense because the scaffold is the expensive part.

Where to buy

Ridge tiles are available from builders' merchants (Travis Perkins, Jewson) and roofing specialists (Burton Roofing, Roofing Superstore, Roofing Outlet). Screwfix and Wickes stock limited ranges. For the best colour match with your existing roof, go to a specialist who can show you the full manufacturer range.

Order ridge tiles at the same time as your main roof tiles, from the same supplier and batch. Colour matching matters and production batches can vary.

Alternatives

For the ridge tiles themselves, there's no real alternative. If you have a pitched roof with two slopes meeting at an apex, you need ridge tiles. But the fixing method is the variable.

Dry ridge systems are the standard for any new extension and the upgrade path for existing mortar-bedded roofs. They eliminate ongoing maintenance and meet BS 5534 without any ambiguity. The companion page on dry ridge systems covers the kit components in detail.

Mortar bedding with mechanical fixing remains acceptable under BS 5534 where supplementary screws or clips are added. It's the right approach for heritage properties where the appearance of a dry ridge system is unacceptable.

Flexim roof putty is a product that appears in forum discussions as a mortar alternative for period homes. It's a flexible, pre-mixed compound that doesn't crack from thermal movement like traditional mortar. Not as widely proven as dry ridge or traditional mortar, but worth knowing about for heritage repair work.

On a flat or very low-pitch roof (below 15 degrees), you won't use ridge tiles at all. That's EPDM or GRP territory with different detailing entirely.

Common mistakes

Wrong profile for the tile type. Half-round ridges on a flat interlocking tile roof leave gaps at the edges. Angular ridges on profiled interlocking tiles don't seat flat. Match the profile to the tile, not the other way round.

Mortar-only fixing on a new extension. BS 5534 requires mechanical fixing. Mortar alone is not compliant. Building control can (and sometimes does) fail this. The fact that some inspectors let it pass doesn't make it right.

Not ordering stop ends. Open-ended ridge tiles at gable ends let wind-driven rain straight in. It's a few pounds per tile and easily forgotten on the order.

Mismatched manufacturer. A Marley ridge tile on a Redland tile roof won't match in colour. Even within the same manufacturer, different ranges have different colour formulations. Order ridge tiles from the exact same range as your main tiles.

Not checking the roofer's work. You can verify ridge tile installation from the ground with binoculars. Check: ridge tiles are in a straight line with consistent joints; stop ends are present at gable ends; no mortar is visible on a dry-fix installation (if you see mortar, it should have clips as well); the ridge tiles overhang the main tiles evenly on both slopes.

Checking your roofer's work

This is the section no other guide includes. Before your roofer leaves site (or before you sign off the roof covering stage with building control), check these points:

1. 75mm overlap on each slope. The ridge tile should cover the top edge of the main tiles by at least 75mm on both sides. Less than this and water ingress in driving rain is likely.
2. 5mm ventilation gap at the apex (dry ridge only). You can sometimes see this from inside the loft space as a sliver of daylight along the ridge. It's the gap between the two top tile courses that the ventilated roll bridges.
3. Mechanical fixings present. On dry ridge, every ridge tile union should have a clip or screw. On mortar bedding, there should be a separate screw, clip, or wire restraint in addition to the mortar.
4. Stop ends at gable ends. Sealed, not open.
5. Tiles within 900mm of masonry walls are additionally secured with nails, clips, or wire (this is a BS 5534 requirement that applies to ridge tiles near gable walls and chimney stacks).
6. Straight line along the ridge. Wobbly ridges suggest the ridge batten wasn't properly aligned before fixing.

Where you'll need this

• Roof covering - ridge tiles cap the apex of the pitched roof and are the final element of the roof covering stage

Ridge tiles appear at the same stage on any pitched-roof extension or renovation project, always as the last piece of the roof covering before the building is watertight.