First developed in Europe in the 1960’s, exterior insulation finish systems (EIFS) were introduced to North America in the 1970’s and subsequently to Australia. As a multilayered exterior wall cladding system, exterior insulation finish systems offer energy efficiency, design flexibility and ease of installation.
Initially specified for commercial buildings, today exterior insulation finish systems are more commonly used on residential developments and single dwellings in Australia as a lightweight, energy efficient exterior wall cladding material.
“The role of EIFS in Australia is growing steadily as architects, builders and tradespeople become more familiar with the benefits and applications of the quality systems that are coming onto the market,” Sandy McPherson of MasterWall , an Australian exterior insulation finish systems manufacturer and supplier says.
A typical exterior insulation finish system like MasterWall comprises a range of components:
· Polystyrene insulation panels which are secured to the exterior wall surface with a mechanical fixing system and/or a specially formulated adhesive.
· A durable, water-resistant exterior base coat, applied to the panels. This usually includes fibreglass mesh reinforcing for added strength and longevity.
· A durable, crack-resistant render system, typically an acrylic co-polymer product.
· Other components include special sealing tape for the panel joints and builder’s paper or similar backing material.
It’s worth noting that exterior insulation finish systems should be installed strictly in accordance with instructions and by experienced tradespeople. The well-known ‘leaky house’ syndrome in New Zealand occurred largely because of incorrect installation of cladding. This led to water ingress and subsequent structural damage to a significant number of buildings. Correct installation of exterior insulation finish systems will ensure optimum performance and that all building regulations are met.
Current practice in Australia relies on the rendering process to seal the face of the building and the openings to the wall system. This is totally contrary to established best practice in more experienced markets. There, it is accepted that a correctly installed exterior insulation finish system includes sealants to all joins and the use of flashing tape and sealants to seal and flash all openings, prior to the application of the acrylic render system.
Manufacturers, such as MasterWall offer the options of supplying components individually, a complete job lot system pack, or a full supply and install service, right through to rendering. The latter with a seven year materials and workmanship guarantee.
“One of the advantages of more than 20 years experience in the polystyrene industry and learning from the leaders in overseas markets, is that we can fully support our products,” McPherson says, “We offer everything from technical and design advice to onsite service and support, comprehensive installation training and product guarantees. It’s world best practice.”
Energy efficiency is one of the performance advantages of exterior insulation finish systems. Compared to traditional batt type insulation inserted between studs, EIFS, because it sheathes the exterior of the building, has fewer thermal gaps. These are places through which air can flow between the interior and the exterior, causing unwanted energy transfer.
Design flexibility is another exterior insulation finish systems benefit, increasingly appreciated by architects and designers – and builders when it comes to construction. EIFS can be used to create a virtually unlimited range of architectural details, many of which would be uneconomical to produce by traditional methods. Cornices, columns, arches and keystones are some of the more popular choices.