The short answer
On new work, yes: BS 5534, the code of practice for slating and tiling, expects tiles to be mechanically fixed with clips, nails or screws, not left to weight and mortar. But the standard is not the law, and an older roof laid without clips is not breaking any rule. What matters is whether the roof you have resists the wind.
Clips hold tiles down against wind uplift. Whether yours need them depends on whether the roof is new, old or being repaired.
What BS 5534 asks for in plain terms
BS 5534 covers how pitched roofs are slated and tiled, and BSI lists BS 5534:2014+A2:2018 as the edition in force. Its purpose is to stop tiles lifting in wind. A tile resting on its battens (the timber laths nailed across the rafters) is held by its own weight and its nibs, but a gale can get underneath and peel it away.
Which tiles does a roofer fix?
The standard calls for mechanical fixing, meaning a nail, screw or clip that physically holds the tile. The detail depends on the tile, the pitch and how exposed the site is. Tile makers publish fixing instructions for each profile, and a roofer working properly follows those alongside the code. Tiles at the verges, eaves, ridge and hips meet the most wind, so they are fixed more firmly than tiles in the middle of a slope.
Exposure explains why a new roof on a hilltop village in the Quantocks or in the open on the Levels needs careful fixing. A clip is a small, cheap item set against the cost of re-laying a slope after a gale.
Is clipping a legal requirement?
No. Marley states plainly that installing to BS 5534 is not required by law. A British Standard records good practice. It is not an Act of Parliament, and nobody is prosecuted for a roof without clips.
Why follow it anyway?
Because a roof that comes loose in a gale has failed, and the standard sets down how to avoid that. Building Regulations approval for a new roof is a separate test, and your building control body decides what it wants to see. A contract can name BS 5534 as the standard for the work, which is worth asking for in writing, and a tile maker's warranty can depend on following its fixing instructions.
On a repair, the roofer fits a like-for-like tile and fixes it the way its neighbours are fixed, using a nail or clip wherever the roof has them. We tell you what the standard expects and what we will do on your roof. The survey photos show the fixings, so the condition of the roof is plain before a price is agreed.
Fixing advice changes with the tile, so no single answer fits every roof.
Why older roofs were not clipped
Plenty of older roofs have no clips at all and are still sound. They went up to the practice of their day: heavy tiles, tight laps, nails on some courses and mortar at the ridge and hips. Fixing detail has tightened as wind damage and testing taught the industry more.
Does an unclipped roof need clips fitted now?
Not automatically. If the tiles sit tight and have not moved, leaving them alone is reasonable. If they are creeping, the causes in why roof tiles slip need finding first, and clips can then hold the courses that remain.
The ridge is where practice changed on paper. Marley explains that the 2014 revision of BS 5534 ended any reliance on bedding mortar by itself at ridge and hip, and bedded tiles now take a mechanical fixing too. Mortar stays in use; it simply stops being the only thing holding the tile. Dry-fix systems, tested to BS 8612, fix the ridge, hips and verges mechanically, and our dry ridge and verge page describes them. Some older mortar beds crumble out, which is a sign to have the ridge looked at.
What this means for your roof
For a new roof or a full re-cover, expect mechanical fixing to be part of the job, and ask which tiles will be nailed or clipped and what the tile maker calls for. For a repair, the question is whether the fixing on the surrounding tiles is sound.
How can I tell if tiles are clipped?
From the ground you usually cannot. A clip sits on the tile edge under the next course, and a nail head is hidden by the course above. A roofer lifting a tile during the survey sees both, and we photograph what we find. Slipped tiles, loose ridge mortar and cracked pointing are the usual signs that fixing has failed.
Keep the tile and fixing details with your papers when a roof is replaced, because they matter if a maker's warranty or a later buyer's survey asks. Walking over tiles to check them can break them, which is why the answer on walking on roof tiles leaves it to a roofer. The pitched roofing page covers the rest of the work. Send photos of any slipped tiles, and we will say whether fixings are the cause.
More on clipping tiles
Do I have to follow BS 5534 on a repair?
No law says so, but a good roofer fixes a replacement tile the way the surrounding tiles are fixed and follows the tile maker's instructions. On a full re-cover the standard is the usual benchmark, so ask for it to be written into the quote.
Can mortar still be used on ridge tiles?
No. Bedding mortar is still used, but since the 2014 revision of BS 5534 it is paired with a mechanical fixing at ridge and hip, as Marley explains. A dry system tested to BS 8612 is the alternative. A cracked mortar bed is a prompt to have the ridge checked.
The full picture: Pitched roofing in Taunton ยท More short answers