Three lines on a pitched roof take the worst of the weather: the ridge at the apex, the hips that slope down the outside corners, and the verges, the edges that run up the gable end. Each has traditionally been finished in mortar. Dry-fix is the alternative, in which the same pieces are held by clips, screws and purpose-made units and no wet mortar is used to bed them.
If your roof needs work at any of these edges, you will be asked to pick one. This guide sets out the decision in the order we work through it on site: what each method is, how it looks, what it asks of you afterwards, where the building limits your choice, and what the figures say. For how one family of products works in detail, read our guide to dry ridge systems. The wider service is on the ridge, verge and dry-fix page.
What mechanically fixed mortar and dry-fix each involve
A mortar ridge is bedded on a mix of sand and cement, or sand and lime on a period building. The tiles sit in a continuous bed that is struck off and pointed. On its own that bed is not enough. The 2014 revision of BS 5534 changed expectations, and Marley's guidance for roofers says every bedded ridge and hip piece should now also be held by a mechanical fixing. So a modern mortar ridge is really a hybrid: the mortar fills and finishes the joint, while a clip, screw or strap carries the load.
Dry-fix in plain terms
A dry ridge replaces the bed with a batten set along the apex, a ventilating or sealing strip and a row of ridge tiles screwed or clipped down. Dry hips and verges follow the same idea, using trays, caps and clips instead of mortar. BS 8612 is the test specification for these systems, and Marley says only tested products can show compliance, so the brand and the fixing kit matter as much as the tile.
One roof, either method
On most ordinary tiled roofs either approach is possible. Where one is ruled out, the reason is usually the building, not a rule against the method, and we cover those cases below.
How each looks from the lane
Appearance is what most owners notice first, and it is where mortar and dry-fix differ most.
The mortar line
Mortar gives a continuous, slightly rough line along the ridge, with a shadow at the joints. On an old clay or stone-tiled house this is the look the building has always had, and a dry system can seem too crisp beside it. Mortar also lets a roofer set every tile to the existing run, taking up small irregularities in an old ridge line that a rigid system cannot absorb.
The dry line
A dry ridge shows tight, even joints and a clean edge, with each tile seated in a mechanical fitting. Some units include a coloured end cap, a vented strip hidden beneath the tile, or a dry verge cap in a matching profile. Viewed from the ground, a good dry system on a modern roof is hard to tell from mortar. On a roof with a clay or natural stone ridge it can show a more uniform finish than the neighbours.
Colour matching
Mortar can be tinted and its texture adjusted with the choice of sand, so a new bed can be brought close to weathered pointing nearby. Dry-fix components come in a limited set of colours, so the match depends on the manufacturer's range and the age of the roof. We show you the options before ordering.
Upkeep and what lasts
The long-term difference lies in how each method ages.
Mortar needs revisiting
Mortar shrinks, cracks and wears as the years pass, and a ridge that is bedded in it will need repointing at some stage. That is routine, not a defect, and our guide to ridge repair costs shows what it typically involves. The mechanical fixings under the mortar mean a cracked joint no longer puts the tile at risk, but the mortar still needs to keep water out of the apex.
Dry-fix needs a different kind of check
A dry ridge has no joint to crack, so there is nothing to repoint. What it asks for is an occasional look at the clips, screws and sealing strips, and a check after severe weather that no unit has shifted. How long a dry-fix system lasts depends on the product, the fixings and the exposure, so we do not promise a lifespan. Manufacturers offer product guarantees, and a guarantee is one thing and the working life of the roof another.
When something goes wrong
With mortar, a failed section can be raked out and repointed locally. With a dry system, the repair is to replace or re-fix the affected units. In both cases it helps to know which system you have. If the roof has changed hands, ask for the paperwork and email us a picture of the ridge if you are unsure.
Working in cold weather
Fresh mortar is damaged by frost, and that governs when work can happen. Our guide to ridge and verge repairs in winter sets out how timing differs between the two methods.
Protected buildings and period roofs
This is where the choice can be taken out of your hands. A listed building, or one inside a conservation area, may call for lime mortar and a traditional detail. Stroud District has 41 conservation areas, and Article 4 Directions, which withdraw some permitted development rights, apply in five of them, Bisley and Wotton Under Edge among them. Whether a given Direction reaches roof work is not spelled out by the council, so put the question to the planners before you alter how a ridge is finished.
Listed roofs
Listed building consent is required for any work that alters what makes a listed house special, and the district council points out that the whole building is protected, front and back, whatever its grade. Swapping a lime-bedded stone ridge for a dry system is a change of appearance and material, so ask first. Replacing like for like is the safer path, and the conservation team can say what they expect to see.
Stone ridges on Cotswold roofs
Cotswold District Council's 2000 guidance records that ridges on stone slate roofs were always cut from dressed stone, shaped to a plain angle. A stone ridge is heavy, and the practical answer is to bed it traditionally and add mechanical fixings, which is what we do. A dry system made for concrete or clay tiles is not designed to carry a stone piece of that weight and profile.
On a listed or protected roof, decide the ridge method with the conservation team first, then the roofer. Changing the order costs time.
How the roof underneath affects the decision
The structure, the covering and the pitch all feed into the choice.
Condition of the ridge board and rafters
A dry system needs a sound timber to fix into. If the ridge board has rotted or the rafter ends have moved, the batten and screws have nothing to hold. Mortar will bridge some irregularity, but it cannot cure a failing timber, and we report on the timber either way when we survey.
Covering and tile profile
Dry ridge units are made for common profiles, such as half-round and angled. An unusual crested or decorative ridge, or an odd old tile, may have no dry equivalent, and mortar then becomes the practical option. Dry hips and verges bring their own considerations, covered in our dry verge guide.
Ventilation
Some dry ridge units let air out of the loft at the apex. BS 5250 advice, as summarised by Marley, calls for continuous 5 mm high-level ventilation on roofs steeper than 35 degrees, those spanning more than 10 m, and lean-to or mono-pitch roofs. If your roof needs that, a vented dry ridge can supply it. We cover the detail in the ventilated dry ridge guide.
Exposure and access
A dry system is quicker to fit and less sensitive to the weather on the day. Steep lanes, terraced hillsides and tight access change the cost of both methods, because scaffold and carrying time are priced in. We put these in the quote at the survey rather than discovering them on the day.
What each method costs
These are national ranges from published guides, not prices from us. They help you judge a quote when it arrives.
| Work | Range | Published by |
|---|---|---|
| Replacing or re-bedding ridge tiles | £300 to £600 | MyBuilder, 2026 |
| Repointing a ridge or hip | £200 to £400 | MyBuilder, 2026 |
| Dry ridge, per metre | £40 to £60 | MyBuilder, 2026 |
| Dry ridge, per metre, before VAT | £50 to £70 | Checkatrade, 2026 |
| Dry hip, per metre, before VAT | £70 to £100 | Checkatrade, 2026 |
Reading the figures
MyBuilder puts a typical dry ridge job at £500 to £1,000. The two sources differ because they sample different jobs, so use them as a rough guide. Mortar is often cheaper for a small local repair, such as repointing a few metres. Dry-fix tends to look better value over a whole ridge, because it is quicker to lay and there is less to revisit. That balance shifts with the length of ridge, access and the tile.
Your own figure follows the survey. The quote covers the work from access to clearing away, so the two methods can be set side by side for your roof.
A way to decide
Work through these questions in order. The first one that gives a clear answer usually settles it.
- Does the house have a listing, or stand in a conservation area? If yes, check with the council before you choose, and expect mortar to be preferred.
- Is the existing ridge stone, or an unusual clay profile? If yes, mortar with mechanical fixings is normally the safer choice.
- Is the ridge timber sound? If not, repair it first, whichever method follows.
- Does the roof need high-level ventilation? If yes, a vented dry ridge deserves a look.
- Is the roof a standard tile on a modern house, with a long run of ridge? Dry-fix is often practical and quick.
If you are still unsure, send photographs of your ridge, hips and verges with the approximate age of the house. During the survey we photograph your own roof, explain what we find and price both methods where either would do. Where notification is needed, we deal with the Building Regulations side, and our workmanship carries a 10-year written guarantee.