Chapter one
A ridge-top village and how its tiles are fixed
High ground on the Forest Ridge means fixing plans are written for the site, not for the street.
Pease Pottage stands on the Forest Ridge, a raised belt of the High Weald made of sandstones and thin clays, the Hastings Beds. For a roofer the useful word in that description is ridge. A house on raised ground has fewer neighbours and trees to break the wind than one in a valley, and the fixing of its roof covering deserves thought to match. Marley explains that the Eurocode method for wind load starts from the site's basic wind speed and adjusts it for terrain, topography and the size of the building. None of that is guesswork done from the pavement. It is the reason we request the tile maker's site-specific specification when a roof here is renewed, rather than nailing to habit, and it is why a survey photograph of your own slope is more useful than a general rule.
At a glance
- Fixings are specified by location and local exposure
- Below a 30 degree pitch, windward suction becomes severe
- BS 8612:2018 is the test standard for dry-fix ridges
1.1 Pitch, suction and the first row of tiles
Marley's rule of thumb is a pitch below 30 degrees; under that angle, suction on the windward side becomes severe. Shallow roofs, such as an extension or a garage added to the side of a house, are therefore the first places we look for lifting. Wienerberger sets one mechanical fixing as the minimum for every single-lap tile, so none rests on weight and friction alone. Marley reads BS 5534 as fixing the perimeter tiles twice. On a ridge-top house the edges, meaning the verges and the eaves, are where a storm starts to take a roof apart, so those rows get the closest inspection and the most secure fixing.
1.2 Ridges and hips, mortar or dry
Along the crown of a roof runs the ridge; at a corner, the hip slopes down from it. Since the 2014 revision of BS 5534 these tiles are screwed or clipped as well as bedded, since a mortar bed by itself is no longer judged enough. A dry-fix ridge swaps the mortar bed for clips and a ventilated roll, and BS 8612:2018 is the standard it is tested to. Either route can be right, and the survey says which suits your tiles and your roof. If your covering is concrete, Marley expects around 60 years of life and MyBuilder says 30 to 50, so age is a reason to survey rather than a verdict. Our ridge tile repairs page sets out the choices.
Fixing facts for an exposed pitched roof
- Code of practice
- BS 5534:2014+A2:2018 (BSI)
- Ridge, hip and verge dry-fixing
- BS 8612:2018 (BSI)
- Single-lap tiles
- Minimum of one mechanical fixing (Wienerberger)
- Pitch below 30 degrees
- Severe suction on the windward side (Marley)
- Perimeter tiles
- Fixed twice under BS 5534 (Marley)
Source: BSI; Marley; Wienerberger, fetched October 2026






