Mechanical fixing of ridge tiles
The New European Standard BS EN 5534 requires all ridge tiles (and ridge tiles used down the hips) to be mechanically fixed and there are a number of options
For the most traditional look, bed in the ridge tiles in the normal way using mortar but before the mortar goes off, use a cleat and screw between the ridge tiles to create a mechanical fixing (this method is illustrated in the image above).
For an ornamental ridge with an upstand, a special Butterfly clip (image right) is available to clip the ridge tiles together and provide a fixing that can be screwed into the roof timber.
This method gives the traditional appearance of a normally bedded roof but does not provide any ventilation (though this can be provided elsewhere on the roof with tile vents).
There are a number of options for mechanically fixing Dreadnought ridge tiles whilst also providing ventilation in the roof. These are the Tileline dryfix ridge system, the Tileline combination dryfix ridge system and the tileline ridgeroll system and they do not involve bedding in the ridges with mortar.
Tileline dry fix ridge system
This offers a maintenance free, simple to install method of fixing clay half round ridges and at the same time forms a bird and insect-proof ventilation gap of 5mm all the way along the ridgeline. In warm pitched roofs where the insulation follows the rafters, it provides high level ventilation of 5000mm2 per lineal meter which would not be achieved with tile vents or ridge vents if there was no air circulation between the individual voids formed by the rafters or counter battens.
Each tileline dry fix ridge pack is sufficient for 3 metres. There are 2 plastic “rails” which are laid on the tops tiles on either side of the apex of the roof, the ridge tiles are laid into these with interlocking plastic fillers between each ridge tile. These are then screwed through a cleat and the plastic interlocking section into the ridge board.
Tileline combination dry fix ridge system
This system uses the rails from the Tileline dryfix ridge system together with capped angle ridges. The whole unit is then fixed into place with a screw and a washer. It provides a neat solution to mechanically fixing the ridge tiles while also providing ventiliation at the ridge.
Tileline ridge roll ventilation system
This system is suitable for all ridge and hip tiles except the capped angle ridge and is quick and easy to install. The product comes in 6m boxes and consists of a corrugated grey coated aluminium roll which is laid out centrally on the ridge and temporarily fixed with double-sided adhesive tape. The ridge tiles are then laid over the top securing the roll in place leaving 10mm joints between each ridge. A cleat is then placed over the joint between the ridge tiles and screwed down into the ridge board.
This system does not require any mortar, though if a traditional look is required, mortar can be used in addition to the cleat but it will then not serve to provide any ventilation. The roll however serves to seal the screw and also to provide a bed for the mortar to sit on.
For ornamental ridges, a butterfly clip is used to attach on to the ridge tiles and provide a fixing that can be screwed into the roof timber.