Traditional plaster finishing is a highly skilled trade: brown or grey gypsum powder is mixed with water and hand applied to interior surfaces. Achieving the right finish with minimum waste requires years of experience and teams of plasterers will be needed on site to complete large projects. The resulting 3-4mm plastered surface will then need five to seven days to dry completely before decorating.
Knauf set out to reduce the time and waste involved while at the same time enabling non-specialists to master the required technique. The result is the Airless Finishes range of spray applied products as an alternative to traditional plaster.
The headline innovation with this product is its application involving a single operative using an Airless spray machine. Knauf Airless Finish is supplied to site ready-mixed, minimising the need for water on site. Applied to plasterboard walls and other substrates, the resulting 1.5 – 2mm finishing layer will be ready for decoration within 12 – 24 hours. The application process allows for any material taken off the surface to be recycled back through the machine, resulting in wastage of less than 1%.
Using the product is straightforward: one day’s training will provide the necessary understanding of the application process, with full efficiency on application gained in four to six weeks, making this a very attractive proposition for jointers, painters and decorators who can multi-task on site.
For contractors, speed is a major benefit. Application is over three times faster than traditional plastering, while the cleanliness of the product means less tidying of the site and reduced drying time allows follow-on trades on site much sooner.
Getting this product to the point where it is an accessible and price-effective option for contractors took time and today’s Airless Finish is the result of a considerable evolution process.
The material itself is completely new for the UK market - the gypsum that forms the basis of traditional plaster is replaced with crushed and milled marble, resulting in an off white finish.
Creating a compound that was fine enough to be sprayed using machinery that is small and light enough to be practical for use on site was the challenge for the product development team, and required close collaboration between Knauf and equipment manufacturers Graco to develop the right combination.
Continual refinements to both product and equipment design took several years, but Knauf continued to invest in this solution, confident of demand for a quick, clean product that requires minimal training to master.
The concept of a spray-applied plaster is a radical departure for site teams, but as soon as initial projects demonstrated the potential of this solution, demand rose sharply. Introduced in 2014, there are now some 5.5 million square metres of interior surfaces in the UK finished with this solution.
Knauf’s CITB-approved training facilities at its Sittingbourne and Immingham plants provide the opportunity for contractors to get up to speed with the application technique fast, and the crack-resistance of the finish is proving attractive to the offsite and modular building sector.
The story does not end there. Responding to a customer question about the possibility of roller application, Knauf went on to develop ProRoll. In the hands of professional trades people ProRoll is a handy solution for small areas of wall finishing, but the ease of application brings this process into the realm of the DIY market for the first time.