What are the benefits and drawbacks of an exterior insulation and finish system? 

Overcladding a building with an exterior insulation and finish system (EIFS) offers many benefits. For starters, it updates the appearance of a tired looking building, which entices renters to want to live there. It also reduces heating requirements, increasing the potential for profitability for the owner. Installing insulation on the exterior of masonry buildings leverages the thermal benefits of the massive masonry walls. This dampens the temperature fluctuations seen by the masonry and leads to energy-saving costs over time.

The main drawbacks are the need to recoat and maintain the system, and installation problems that result in leakage. However, installation problems can be avoided. A proper EIFS installation will shed water and be sealed at the windows and other wall penetrations so that leakage doesn’t occur. When an EIFS is applied over top of a solid masonry wall, the durability of the masonry system can usually deal with minor leakage, particularly with today’s drained EIFS cladding installations. But, as with any large repair or renovation, it is worth the cost to have a seasoned consultant specify and design with proven products, and then then to have the cladding installation reviewed by an experienced contractor. Quality products, used in a good design and expertly installed, will minimize the risk of future performance issues.

Paul Chisholm, P.Eng., is a senior project manager at Construction Control Inc.