Exterior Insulation Finishing Systems are composed of several different layers and as such, some of the cementitious layers, including the finished top coat, are applied fully by hand. Even though EIFS' construction allows for a nearly perfect and flat wall, because of this previously mentioned fact, there may be some dispute as to the "flatness" of a wall when it is complete. Nine times out of ten, this is merely due to an inaccurate perspective brought on by poor lighting or a lack of knowledge on the part of the building owner.
Analyzing the "flatness" of an EIFS wall
There is no standard form of measurement with regards to the flatness of the top of an EIFS wall, and it really can be completely held in the eye of the beholder. It is interesting to note, however, that there are certainly specifications for the flatness of the substrate to which the EIFS is attached, but not for the EIFS finish itself. The viewer's perspective of "flatness" can depend on numerous variables that must be taken into consideration when attempting to gauge how flat the surface actually is. Some of these factors include:
- Time of day: the middle of the day, when the sun is brightest and directly overhead, provides optimal viewing of an EIFS wall. Morning and late afternoon lighting conditions may shine light on the EIFS wall in a manner that actually creates the look of an uneven surface, and could be disrupted by shadows.
- Season: the sun shines at different brightnesses throughout the year, depending on the season and the strength of the rays hitting the earth. In Ontario, the sun is strongest in the summer between 10 a.m. and 4 p.m.
These lighting situations can make a wall with the slightest waviness look much worse than it actually is.
The very nature of EIFS is that it provides a flat and seamless look. However, if one person thinks they see an area of the wall that is not perfectly "flat", others may soon follow suit. It is important to note that EIFS coatings are applied by hand, and other hand-applied substances, such as stucco, allow the installer to build up layers of the substance, so it can look perfectly flat when all is said and done. With EIFS, this is not the case as there is no room for such an application, and making the individual layers too thick will make the EIFS very prone to breakage and cracking because its flexible qualities would be substantially reduced.
Communicate with your audience effectively
The audience of the EIFS wall can include anyone living within the building, owning the home or building and those who are actually overseeing the work being done. These individuals or groups may have extensive knowledge of EIFS application or none whatsoever, and it is up to the contractor or installer to determine whether or not flatness is an issue the audience will generally be concerned about. It's a wise endeavour to ensure these possible issues are explained beforehand, as well as effectively imparting the fact that any "waviness" the audience thinks they can see is only an aesthetic issue. They also must be made to understand that every form of wall-cladding has similar issues one way or another, and the "waviness" is not unique to EIFS.
Creating a sample piece of EIFS using the same materials, colour and texture the designer or builder wants for their own building can be an easy way to show them what the finished project will look like, as well as help determine how they'll feel about the potential waviness.
If a designer or building owner seems determined to have a completely flat wall regardless of your concerns or warnings about the physical limitations of wall-cladding materials, bringing up the subject of overall cost to absolutely perfect the wall up can have them change their mind quite rapidly, or convincing them to incorporate further design elements like aesthetic reveals, which will break up the large pieces of EIFS that are so prone to waviness, may help the finished look overall. Concentrating on extreme perfection with regards to flatness only on extremely visible areas of the building, such as entryways, as opposed to seldom-seen areas, such as near grade of very high up on tall buildings, can also save time and cost.
Other factors that emphasize imperfections
The building owner or designer must be made aware of any other variables that can emphasize the "waviness" of the EIFS surface that are completely out of the hands of the contractor or installer. One of these factors includes spotlighting, which is a light placed in extremely close proximity to the EIFS surface and that will shine brightly on any imperfections.
The rougher the texture, the more difficult it is to see imperfections, and this is the reason many ceilings use that "popcorn" texture - to hide aesthetic imperfections. Thicker base coats can also achieve this effect to some degree.
It is also very important to understand the complexity of repairing an EIFS wall with regards to only fixing the "flatness" itself, and it may mean replacing the whole thing. This fact emphasizes the importance of considering establishing some kind of flatness agreement, meaning determining in advance what the home or building owner, designer or architect expects.
EIFS is installed by skilled craftsman, and by hand. It is impossible to create a perfectly flat wall. If the person overseeing the construction is aware of this fact, they will not be disappointed in the end of the job or with the finished product.