It’s a relationship that might best be described as complicated. Mortar and ridges tiles, an age-old union forged in sand and cement, but one that has been showing cracks for a while now.
While one side of a roof could talk fondly of mortar as a weatherproof ridge tile bonding that has lasted on its own for centuries in every weather condition imaginable, the other side might lament mortar’s inability to sufficiently cope with environmental changes and blast its regular need for maintenance.
While both of these arguments are valid, which is a more accurate reflection of reality? Well, if you are to go by the latest European Standards, the present and future of fixing ridge tiles is dry ridge.
BS 5534 and more recently BS 8216:2018 state that mortar should no longer be used as the only means of fixing tiles and fittings onto roof ridges, with mortar-only applications limited to certain repair jobs and heritage properties only.
Even before these standards were drawn up, the popularity of dry ridge had been growing rapidly among the roofing trade, with roofers deciding to down their cement buckets and trowels for plastic unions and clamps after discovering the advantages of dry ridge.
Maintenance free and easier to install, dry ridge systems, such as those produced by APEX and Cromar, are widely recognised as being able to withstand the worst the outdoors can muster, a weakness often thrown at mortar. But what is a dry fix system exactly and how has it become the most popular ridge tile fixing method in the UK?
What is a Dry Ridge System?
A dry ridge system is the method of mechanically fixing ridge tiles to the ridge of a roof without the use of mortar.
Though there are a few different systems within dry fix itself, by far the most popular approach is with ridge roll ventilation. This method involves covering the roof batten with ridge ventilation roll and adhering it to the tile or slate. One by one, the ridge tiles are then installed over the ventilation cover to secure it in place and are laid across the apex of the roof using plastic unions, clips, clamps, screws and washers.
The unions secure the tiles together with a small expansion gap while the clamps are placed between tiles and screwed down into ridge board or batten. This provides a windproof fixing that will ensure no tiles come loose over time, accounting for natural expansion, contraction or any other type of roof movement. Fitting a dry fix system can be done regardless of what the weather is doing at the time.
Once fully installed, the top of the roof will look very similar from street level to how it would if bonded with mortar. However, unlike mortar bonded ridge tiles, a dry ridge system should not require regular (and often unsafe) trips up to the roof to assess and maintain loose or missing ridge tiles.
This makes dry fix systems a safer, less bothersome option that is cheaper too. Although the initial outlay on mortar costs less than a dry ridge kit, not having to worry about bad quality mortar mix or environmental movement will mean less maintenance over the years, making dry ridge the more affordable choice for most.
The above is only a summar of of dry ridge and does not account for other factors, such as removing roof tiles, cutting away felt, the possibilities of needing to add another batten and fixing the end ridge tile.
Why is Everybody not Adopting Dry Ridge?
Many roofers still prefer to use mortar on their repair jobs and wherever they can, not only out of faith in the reliability of mortar, but out of reservations over dry fix systems, despite it being made code of practice by European Standards.
Advocates of dry fix will tell you how a mechanical fixing method has a lifespan superior to that of mortar bonded ridges, while those loyal to the sand/cement mix will suggest that it is the plastic dry ridge fixings that cannot be trusted.
This belief is predominantly based on opinion rather than factual case studies. As dry ridge systems are still relatively new, not enough time has passed for dry ridge to be properly assessed. Some sceptics still point to a supposed brittleness of plastic in the face of severe weather and the sun, however all good dry ridge systems will only use material that has been tested to ensure its fully UV resistant.
Dry Ridge at Sterlingbuild
Here at Sterlingbuild we sell several different dry ridge systems. All of them come in kits with a standard 6m ventilation roll. Cromar also offer 3m and 5m dry ridge kits for shorter ridges.
All dry ridge kits come with roll, unions, screws, washers and also brackets should you want to add a batten/s above the ridge board for additional height or if working on a modern trussed roof.
Two different Manthorpe dry ridge systems cover clay ridges and concrete, while Ubbink and WonderBUILDS produce universal dry ridge tile systems for clay and concrete ridges.
Our two favourite dry ridge systems, however, come from Cromar and APEX, both of which can be purchased for delivery within 1 working day.
The three sizes of the universal Cromar dry fix ridge system can be used on almost all types of ridge tiles with the unions included in the all-in-one driy ridge kit compatible with most ridge tiles. Cromar dry ridge is straightforward to install, coming with everything you need to create a windproof, fully ventilated dry ridge roof.
Apex is available at at our lowest dry ridge system price, coming with a multibuy discount to bring costs down further should you want to stock up on the product or need dry ridge kits for several roofs. The ventilated roll that comes with the APEX dry ridge system is made of aluminium reinforced corrugated fabric to provide strong ventilation with air permeability of 380cm3/cm2/s at 200 kPa.