The term "stucco" is an ambiguous term, but is most commonly used to refer to EIFS in the Toronto and surrounding areas. EIFS is the beautiful material you see on homes that has a fine texture, is typically customized with mouldings, and has an unlimited range of colours. Under the surface, it has a layer of modified cement with an embedded fibreglass mesh that makes it simultaneously strong and flexible (to prevent cracking), a layer of energy preserving insulation, and a weather barrier that prevents mould in your walls by keeping moisture from entering them.

EIFS itself has a spotted history, and there are many different systems and materials out there. When acquiring bids, you want to ensure that all the contractors are specifying the same system - the most up to date one. Previous EIF-systems used inefficient screws to adhere the insulation, did not have a weather barrier and used cheaper materials, resulting in pre-mature failure.

Exterior Insulation and Finish Systems (EIFS, or “synthetic stucco”) have seasonal application limitations – that is, they can not be applied when the ambient air temperature drops below 5 degrees Celsius… within 24 hours after any coating is applied. The ambient air temperature would be the temperature outside, with factors such as the sun or wind figured in. For example, it could be below 5 degrees Celsius when the actual temperature is 10 degree and a wind chill is factored in. The reasoning behind it is that the EIFS components (weather barrier, styrofoam adhesive, base coat and finish coat) contains water. When the temperature drops below 5 degree Celsius, the evaporation slows to a point that the materials will cure too slowly. This can result in efflorescence (a white powder being drawn out of the material) in the basecoat or uneven texture/colour in the finish coat because it has cured at different rates.

Then there’s the risk of the temperature dropping below zero degree Celsius, causing problems like finish coat delamination (peeling) and styrofoam adhesive failure (the wall my start to crack and fall off in sections). As the water in the products freezes it expands, creating larger spaces in the coatings that weakens it. These conditions apply not only to the application of the materials, but their preparation (mixing) and storage as well. It is always recommended to provided a heated room or area somewhere such as the basement to store the materials, off the ground