Question answered
What is BS 8612?
The short answer
BS 8612 is a British Standard published by BSI on 31 January 2018, with a title that covers dry-fixed fittings for ridges, hips and verges on slate and tile. Marley describes it as the yardstick used to test dry verge, hip and ridge fittings. It deals with factory-made systems that hold those tiles mechanically with no mortar bed, and it sits beside BS 5534, the code of practice for fixing slates and tiles.
BS 8612 is the 2018 British Standard covering dry-fixed systems for the ridge, hips and verges of tiled and slated roofs. It gives manufacturers a shared test specification to work to.
What the standard covers
BS 8612:2018 sets the specification for systems that fix ridge, hip and verge tiles without a mortar bed. In a dry-fixed system the tiles rely on clips, brackets, screws and a carrier section in place of a strip of mortar. The standard exists so such systems can be judged against shared tests, not by each maker's own yardstick.
The roof edges it concerns are the three most exposed: the ridge along the apex, the diagonal hips of a hipped roof, and the verges where a slope meets a gable. Wind attacks all three first, and they are the lines where a mortar bed has traditionally cracked or dropped out.
Which tests a given system has passed, and to which edition, appears in the maker's technical data, so ask for that sheet before you agree to a product. A named, tested system is easier to compare than a generic kit, and it tells you what the clips and sections were designed to do.
How it relates to BS 5534
BS 5534 is a separate document, the code of practice for fixing slates and tiles on pitched roofs and vertical cladding. BSI lists the current form as BS 5534:2014+A2:2018, published on 28 February 2018. It describes how coverings should be fixed, including the fittings at ridge, hip and verge.
The two documents do different jobs. BS 5534 tells the roofer how a roof should be fixed, while BS 8612 tells the manufacturer how a dry-fixed system is tested. Since the 2014 revision of BS 5534, mortar is no longer the only thing holding a ridge or hip tile down; a fixing is expected as well, and a system that meets BS 8612 is one way of providing it. Neither route is wrong in itself. What counts is that the finished ridge or verge is held down, and that the choice was made for your roof rather than out of habit.
Our page on how ridge tiles are fixed shows the working sequence, and BS 5534 ridge fixing goes through that other standard. The wider service is on our ridge tile repairs page.
Is a dry-fix system compulsory?
No. Marley's account of BS 5534 says installing to the standard is not required by law, and mortar-bedded ridges are still built with mechanical fixings added. Nothing makes dry fix the only approach. Marley adds that the 2018 amendment accepts a heritage roof may call for something else, and suggests owners take advice from their council planners and a conservation specialist.
So the choice is about the roof, not about a rule. On a modern tiled roof facing the sea, a system tested to BS 8612 is a sensible choice. On an old roof where appearance and materials matter, a traditional mortar bed with hidden fixings may suit better. Our page on dry verge systems looks at the verge side of that choice.
What to ask a roofer who proposes dry fix
Some simple questions reveal how carefully a system was picked. Which system is it, by name and maker? Does the maker's data say it was tested to BS 8612? Is it designed for your tile profile and the pitch of your roof? How are the end tiles dealt with, and the junction at a chimney or wall? A good answer names the product, the tile it is made for and the way the end fittings are secured. A roof near Shoreham airport can need special input from the tile maker on its fixing specification, so your roofer should know to ask.
Ask for the fixing method to be written into the quote, and for photographs of the ridge from the survey onwards. A ridge is hard to inspect from the ground once the work is finished, so the record matters. Salt air, gales and driving rain test every joint, and a ridge system fixed properly once is worth more than one repointed every few winters. We show you pictures of your own roof, and our quote is written.
Where dry fix earns its place on the coast
A coast that faces south takes gales and driving rain, and the top edges of the roof take the worst of it. A mortar bed can crack as the roof flexes in strong wind, and once water has found the bed, frost can do further damage. Mechanically fixed tiles stay put even when pointing fails, which is why dry fix often suits houses on the seafront and the open Downs.
That does not make it the only answer, and it does not make a loose or noisy cap acceptable. If a dry verge is rattling, the fixings need attention; see why a dry verge rattles for the noise itself.
The dry-fix standard: two more questions
Does BS 8612 apply to every type of roof tile?
The standard is titled for slating and tiling, but each system is made for particular tile profiles and pitches. Check the maker's data for your tile type and slope. A system that suits a concrete interlocking tile may not suit a plain clay tile or a slate.
Can an old mortar ridge be converted to dry fix?
Often, yes. The old tiles are lifted, the bed is cleared and a dry system is fitted with the tiles clipped on. The condition of the roof, the tile type and any conservation or listing constraints decide whether it is a sound choice, and the survey will show us.
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