Ridges protect the top layers of slate and tile. If the ridge capping is blown off, the top courses of slates or tiles can be quickly lost.
Zinc ridge capping
Zinc or aluminium ridge cappings are frequently used on slated roofs. However, lead ridges will last longer so are preferred.
Concrete ridge tiles are bedded in mortar or dry fixed with special clips and stainless steel screws. If bedded in mortar, the end ridge tile is vulnerable to lifting.
Repairing ridges on slate roofs
Ensure ridge capping are replaced as a matter of urgency. Access to the roof will be the highest part of the cost of repair, so get the rest of the roof checked over at the same time.
The ridge protects the slates and tiles. Neglect of the ridge has led to more expensive repairs.
Lead ridges should be dressed around a raised timber ridge pole and laid in sections. Each length of lead ridge should overlap the next section by 150mm. Lead or stainless steel clips fixed to the ridge pole are clipped over the lead flashing. Patination oil should be applied to new lead to prevent oxide staining to slates below.
Zinc and aluminium ridge pieces are fixed in a similar fashion.
Lead ridge
Missing end ridge tile. This ridge was ‘wet fixed’ with mortar.
Repairing concrete tile ridges
Dry ridge. Ridge slates are fixed to a plastic strip.
It is usually possible to replace a concrete tiled ridge with a dry ridge – where the concrete tiles are mechanically fixed and no mortar is used. These products hold the ridge tiles securely whilst allowing for ventilation to help keep the loft dry. However, you can’t rely on these systems alone to vent the roof, and you will need eaves vents and possibly other additional roof vents.
Sagging ridge. May be caused by rafters spreading due to rot.
Hip roofs
The corners of hip roofs can be dealt with by:
- standard ridges
- lead soakers
- lead ‘bottle’ ridges
Hip soakers. Flashing is under slates at corner.
Professional help recommended?
Although the work may appear straightforward, ensure your builder or tradespeople have the skills for the job. If in any doubt, get professional help to specify and organise the repair.
Who pays?
- Roof repairs are normally a common responsibility.
