Koraflex Plus Q&A

// the building envelope

Koraflex Plus has it all covered: a specialist solution for faster, easier and greener roof flashing. Wienerberger – the UK’s leading provider of building material solutions – has announced the latest addition to its range of leak-proof roof flashing solutions. Koraflex Plus offers a combination of easy installation, environmental performance and long-term value, with a choice of three colours. Here, Wienerberger answers common questions surrounding Koraflex Plus and what makes it stand out from other lead-replacement flashing solutions.

Q. Why create a lead replacement flashing product?
Lead is undoubtedly the king of roof flashing materials.  It is the ideal material in terms of performance, workability and durability; with its low melting point and easy malleability, it can be fashioned into virtually any shape.  Lead in roofing has been around for centuries, used by the Romans and Normans as a gutter and flashing material, however there are some downfalls to using lead, which is why we have developed a lead replacement flashing product.

Spiraling costs of metal have led to a huge increase in thefts of lead from buildings. This can cause major damage to an unprotected building through water ingress, as well as the inconvenience during remedial works and the resulting potential increase in insurance premiums. Lead replacement flashing materials are only of value to the installer, building owner and occupants; they have no re-sale value as scrap so deter theft.

Some types of roof flashings are completely hidden when installed; for example, soakers used to weather the junction between a wall and plain tiles or slates, or continuous secret gutters used with single lap tiles at side abutments. Therefore, roofers will often choose to use lead replacement products for these types of flashings, as appearance is not important. Lead replacement products are also up to 80% lighter in weight than lead, making them easier to transport in bulk, handle on the roof and to install without the use of any special tools or equipment.

These are some of the reasons as to why we developed Koraflex Plus.

Q. What distinguishes Koraflex Plus from other flashing products currently on the market?

Koraflex Plus is a high-quality lead replacement flashing solution. It uses the same methods and tools that would be used with lead, meaning the installation process is just as easy.  The product features a butyl adhesive backing, which alleviates the need for prefabrication or welding. Not only this, but the material is incredibly flexible, stretching 70% lengthways and 15% width ways.

What distinguishes Koraflex Plus from other flashing products is that it is an environmentally safe product. Having similar properties to lead, such as easy installation and appearance certainly enhances the benefits of using Koraflex Plus. Yet, as Wienerberger’s product does not contain lead, there aren’t the drawbacks that can often be associated with this, including the negative impact it has on the environment and to those installing the material.

Q. How might Koraflex Plus help architects and roofers work better?

Architects can benefit from Koraflex Plus as they can design a system knowing it is covered with a RoofSpec® guarantee, which provides peace of mind for future liability and its long term value.

Koraflex Plus also does not require the application of patination oil, which can save roofers a considerable amount of time when working on a project. It is a traditional skill for a roofer to remember to use patination oil in the correct way and can be time consuming, so without the need of this, resources can be saved. With this traditional process, if the patination oil has not been applied, then there is a risk of staining and streaking from the lead flashing. However, with Koraflex Plus this challenge is removed.


Q. What are the benefits of using a lead-free flashing product, such as Koraflex Plus, for roofing?

Lead is a very popular product due to its easy installation and long-term value, it has been used for many years and workers are comfortable with using the product. However, the main benefit of using a lead-free flashing product such as Koraflex Plus is that you get these benefits but for a better price. Housebuilders can benefit from a cheaper purchase cost, driving their overall costs down but not at the expense of quality. It still offers long term value, having the ability to survive any extreme conditions just as lead would.

Other benefits of using a lead-free product are that you can harvest the rainwater and be sure you are not being contaminated by lead. Being both lead and solvent-free ensures that Koraflex Plus doesn’t have the risk of any chemical leaching and makes it suitable across all roof types, including water harvesting systems.

Finally, lead is a highly recognisable product, which can often leave it exposed to theft. Koraflex Plus is available in a standard grey but also in red and black, which can be chosen to lessen the probability of it being stolen.

Q. What long-term value does Koraflex Plus give to roofing structures?

The long-term value that Koraflex Plus offers is excellent; the flashing product benefits from being extremely resistant to UV and temperature variation from -40°C to 90°C, with a 15-year Wienerberger RoofSpec® guarantee and a 25-year product warranty. With the RoofSpec® guarantee, reassurance is given that the roof system will continue to perform well for years to come, with the flashing solution itself ensuring the system is watertight and leak free. It is also very highly colour stable and gives an excellent finish and quality that is durable and pleasing to the eye.  

Q. How does the product help housebuilders meet the sustainability agenda?

Koraflex Plus helps meet the sustainability agenda by being both lead-free and solvent-free. As a result, it doesn’t risk chemical leaching and plays a part in reducing the amount of lead in the environment. Being lead-free means that the product eliminates potential health and safety risks associated with working in close contact with the material, therefore benefits both the workers and the environment. The product is also approved by the British Board of Agrément (BBA).

For further information please visit http://www.wienerberger.co.uk/. Follow Wienerberger on Twitter at https://twitter.com/wienerbergeruk.

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