The application of external wall insulation (EWI) to existing buildings presents a huge energy saving opportunity. It also presents detailing challenges for the installer, particularly at the eaves and verge in instances where there is insufficient overhang to cover the depth of the new wall insulation.
Current industry practice for external wall insulation relies on the use of basic trims to deal with the interfaces between wall and roof. These trims are normally fitted below the existing gutter and facia boards. Corners junctions between eaves and verge are normally made up on site with varying degrees of success, whilst critical junctions often rely on mastic sealants as the primary line of defence against water ingress.
The resulting arrangements from these practices are often of questionable quality from visual, weathering and cold bridging viewpoints. The weathering risks and potential for failure are not hard to foresee, even on projects where the installers have been as careful as possible.
Instead of fitting below the old gutter, our EWI Pro Gutter replaces it altogether. This makes the whole arrangement much simpler, both visually and technically. There is no longer a facia board that may rot over time. Neither is there the normal trim/silicone/wall junction where water may eventually find a path to the back of the insulation.
Instead of the current messy detail, EWI Pro Gutter joins the roof to insulation in a simple, robust and weather tight manner. A similar tray section can be applied to verges and does a similar job. The two have been designed so that they join neatly at the corner. The clean lines and neat finish of the system are its second great advantage.
The third advantage of the EWI Pro system concerns cold bridging. Existing practice stops the insulation before the top of the wall, leaving a cold strip approximately 150-200mm wide. As well as increasing heat loss, this approach also greatly increases the potential for condensation on the inside face of the wall and therefore mould growth. EWI Pro Gutter greatly reduces the heat loss at this junction, thereby increasing the surface temperature of the inside face of the wall and reducing the risk of condensation and mould.