Insulation

The ROOFMATE MinK System, from Dow Building Solutions, could be the answer to minimising heat loss from flat-roofed buildings and supporting the UK’s carbon reduction goals.

Flat roofs are particularly favoured in public buildings, such as hospitals or schools, as well as commercial buildings, such as offices or shopping precincts. However, heat loss from such structures can be as much as 25% of the total. Any improvements in preventing heat loss from them has significant benefits for energy saving.

In conventional flat roof insulation systems, thermal insulation is in direct contact with the roof deck, with a waterproofing layer on top and the build-up secured against wind uplift.
Dow created the ‘inverted warm flat roof’ system thirty years ago, allowing the waterproofing layer to be laid directly onto the roof deck with insulation on top. This protects the waterproofing from thermal shock and dramatically reduces the risk of condensation below the roof.

Although the inverted warm flat roof system remains an important method of roof design, rainwater can percolate through ballast, penetrating joints between insulation boards. This cools the surface of the waterproofing membrane and reduced the roof''s thermal performance, meaning that insulation thickness has to be increased to compensate for this ''rainwater cooling effect''.

To improve the thermal performance of buildings, dramatic increases in insulation thickness are required, increasing costs and adding serious complications to roof design and installation.

According to Dow Building Solutions, the answer is to use a water vapour permeable membrane, ROOFMATE MK, in combination with the properties of its insulation layer, STYROFOAM roofing product ROOFMATE SL-A. Together, the system is known as the ROOFMATE MinK System. It helps to minimise heat loss due to rainwater cooling, and therefore the amount of insulation required.

Jayne Law, UK and Ireland sales manager for Dow Building Solutions, explained: “Positioning ROOFMATE MK as a separation layer between ballast and insulation prevents rainwater penetrating through to the waterproofing, which is instead directed to the roof drainage. Rainwater that does penetrate evaporates via the ROOFMATE MK ‘breather’ membrane.

"The system enables more efficient use of insulation as less is needed for the same results, as well as fewer journeys to construction sites, meaning fuel savings, because less material is required. It also allows a significant decrease in the weight of ballast required to secure the roof against insulation board flotation and wind uplift, bringing yet more environmental advantages."

The ROOFMATE MinK System has been awarded the UK Chemical Industry Association’s highest award for innovation. Dow Building Solutions also offers STYROFOAM-A blue extruded foamed polystyrene insulation, GREAT-STUFF polyurethane foam sealand, and INSTA-STIK polyurethane adhesives, as well as a range of accessories designed to help improve the energy efficiency of buildings.

www.styrofoam.co.uk