The roof is one of the most vulnerable areas of any building and has to battle against wind, rain and temperature changes. The roof is also an important aesthetic consideration, adding to the overall design of the building. Mortar bedding has been used by roofing contractors for years but if the wrong mortar mix is used or the bedding is done poorly it can be a weakness in the roof system. Failure of the mortar bedding at any point in the roof’s life could mean dangerous loose fittings so regular inspection or maintenance is necessary. Sarah Hanlon, Product Manager at Marley  Roofing  Products points out that “Dry Fixing is ideally

suited to combat climatic extremes, ensuring that the roof actually functions effectively for the life cycle of the products. Crucially, as Dry Fix eliminates the need for mortar and uses mechanical fixings to secure the hip, verge and ridge components it is also faster to install – a definite benefit to the customer”.

The idea of Dry Fix has actually been around for almost 20 years although take up was originally slow, with mortar still being used on 8 out of 10 roofs.* However in recent months major manufacturers such as Lafarge Roofing, Marley Roofing Products and Sandtoft Roof Tiles have launched new awareness campaigns around Dry Fix. Their products are designed to satisfy the requirements of BS 5534 for fixing. This way of working is now becoming increasingly popular and most roofers who try it are immediate converts.

In addition, there has been a drive towards improving quality standards, prompted by the Government and industry associations such as the NFRC.

Dry Fix systems eliminate the need for mortar bedding ridge, hips and verges and come with many benefits. Quick and easy to fit, Dry Fix allows a cost effective, maintenance free solution. With Dry Fix it is either fixed correctly or it’s not.

Using a Dry Fix system makes installation significantly quicker. Stuart Pocock, Accessories Manager for Lafarge Roofing, comments “In recent trials of our Rapid Range, from the Redland range of Lafarge Roofing, the roofing contractor averaged time savings of 33% in comparison to wet mortar”.

Mortar bedding generally provides sufficient tensile bond strength to resist wind uplift but the strength of the mortar bond can be affected by several factors, including the mortar mix, type of sand, quality of workmanship and differential movement of the roof structure. Therefore there are circumstances when the mortar cannot be relied upon to resist wind uplift. Dry Fix systems can be used to remove the problems associated with wet mortar. Sandtoft recently undertook some research which confirmed the increasing importance attributed to dry fix by architects and housing associations, particularly the latter as they look for extended maintenance periods on their properties. Nick Oldridge, Sales and Marketing Director at Sandtoft Roof Tiles adds “Importantly, fixing can take place in all weathers with total confidence in a consistent finish every time. There are no problems with unsightly mortar runs either, and the roof ridges and hips are then essentially maintenance- free.”

In addition, the major manufacturers also incorporate ventilation in accordance with requirements of BS 5250 for ventilation.

So why isn’t Dry Fix the norm by now? The main drawback has been the cost. If you look at the overall cost of installation then mortar bedding is the cheaper option. However, this is very much a short- term view. Instead consider the whole life cost of the roof and benefits of Dry Fix become clear.

Take for example, the case of Stoke on Trent City Council. Some eight years ago the Council made the decision to reduce the cost of maintenance as Phil Brundrett, maintenance strategy officer, explains “We are responsible for 22,000 houses and are constantly re-bedding hips and ridges as mortar fails. Stopping the problem means we have money to spend elsewhere. With a Dry Fix system there is no maintenance liability”.

The major manufacturers provide Dry Fix systems that are both compatible with their own product ranges and suitable for other manufacturers’ products. Ventilation manufacturers such as Klober and Hambleside Danelaw are now also producing Dry Fix products (see details in the news section earlier in this magazine). This gives the roofing contractor greater versatility and choice and the products are easily available from your local branch.

We are always available to answer any questions you have to help you make the right choice of product for your next job.