Most of us, at one time or another, have gotten into a heated discussion with an owner or architect about the aesthetics of a completed EIFS project.
Aesthetic problems can include color, texture, flatness, general workmanship and all manner of subjective judgements. This month's column will give some insight into matters worth considering when dealing with the thorny issue of color and texture variations.
First, the key thing to understand is that there are no published standards for color correctness of EIFS finishes. Since there is no formal protocol for rendering technically correct conclusions in this matter, in the end, it all boils down to a matter of opinion. Experience is thus a factor in rendering such opinions. In other words, if you've seen enough completed EIFS jobs, then you will know what is OK and what's not.
Paint the town
Sometimes the color of the EIFS is just plain wrong. In such cases, no matter how you look at it, the color doesn't even come close to matching any physical EIFS sample or any color chart. Whatever the cause, gross color problems can often be remedied by simply painting over the EIFS finish with ... paint.Most EIFS finishes are paintable, but be careful, as some have special formulas that are not compatible with common paints. Usually a high-quality exterior latex water-based paint works fine on EIFS finishes. Better yet is to use the paint version of the EIFS manufacturer's finish (it makes its finishes with basically the same formulas, but without the aggregate, and thus makes it a "paint"). Using the same manufacturer's product has the advantage of known compatibility with its own materials, as well as matching the sheen and color of the original finish. In case you haven't tried this, you can make "EIFS paint" from old EIFS finish. If you happen to have a pail of leftover finish that matches the repair area, you can strain the finish through cheese cloth. This removes the grit and leaves you with paint.
When painting, especially on older buildings, the old surface needs to be cleaned before it is painted. Usually a good scrubbing with soap and water and a stiff bristle brush is enough, but sometimes oily residues get on the finish. Oily residues are often not removed with soap, and oils can inhibit proper bonding of the new paint to the old finish.
Be careful about using power-washing equipment to clean the EIFS finish. Sand blasting can literally remove the EIFS finish, as will high-pressure water blasting. Water power washers can be used, but the trick is to use a lot of water and low pressure, and not vice versa. Be careful.
Also, be careful not to use solvent-based paints unless you are positive that they are compatible with the EIFS coatings and the EIFS insulation. Solvents can leach through the EIFS coatings and attack the foam, literally dissolving it. EPS-type foam is much more sensitive to solvents than the polyisocyanurate type.
Painting EIFS is usually done using a roller and a brush. The roller is good for the field of the wall and the brush is used for detail areas. Spraying also works, but the overspray also seems to miraculously end up on a lawyer's BMW a few blocks away. Oh, joy.
Sometimes when painting an EIFS, the idea is presented of painting over the sealant. The idea is to make the wall all one color, including the sealant. True, some paints do adhere to some sealants, but a lot do not. If the paint doesn't stick, it will flake off. Also, keep in mind that few paints are as elastic as a sealant. So even if the paint sticks, when the sealant stretches, the paint will split, leaving an alligator effect.
Also be careful using paints with high vapor resistance. High vapor resistance means that the paint has a low ability to allow water vapor to pass through it. In heating climates the EIFS lamina needs to be able to "breath," thus allowing moisture to dissipate. Epoxies and urethanes, for instance, tend to seal the outside surface of the EIFS, preventing the water vapor present in the wall for passing harmlessly toward the outdoors due to diffusion in heating climates. This can lead to condensation problems. For example, if water condenses between the basecoat and the foam, it can cause the EIFS lamina to lift off due to the expansion of water that occurs when water freezes.
If you are changing the color of an EIFS finish from a light to a dark color, be aware that dark colors absorb more heat than do light colored ones. This in turn raises the temperature of the EIFS lamina. The temperature can go high enough, in extreme cases, to melt the foam behind the EIFS. EPS type foam has a maximum service temperature of about 165 degrees F. It is possible for an EIFS lamina to get that hot under extreme conditions. So don't think that this is just an issue in desert climates. It can also occur in northern climates with high altitudes and clear skies.
It goes without saying that if you order the same color finish for repairs as the original that was used on an old building, the two colors won't match. Obviously the original finish has aged, and the new one is fresh. Some people try to get around this by matching the repair paint to the aged, original finish. This works when the repairs are made, but the two colors will, eventually, age to two slightly different colors.
Sometimes what appears to be a color problem is actually a change in texture. Painting over a texture that varies can help, but is usually not a cure-all, since the old texture still shows through. True, from far away you can't see the texture anyway, but close up you can. Keep in mind that painting tends to fill in the texture, making the texture look flatter and less crisp. Painting is not a guaranteed cure for texture problems.
Color me bad
If the texture is truly a mess, sometimes the only way around it is to apply a new finish over the old finish. It's difficult to apply new finish directly over old finish, as the texture of the old finish prevents the new finish from being troweled properly. The usual approach is to fill in the old finish to make it smooth, and then to apply the new finish over it. Often a non-cementitious basecoat adhesive, without reinforcing mesh, works well to fill in the texture of the original finish.When painting an EIFS or applying a new lamina, it's important to agree in advance what areas need to be fixed. This means getting together a group of cooperative souls and marking up the areas that are "agreed to be bad" on a set of elevations. Then comes the hard part: how to decide where to stop or stop the repairs. Similarly, it's a good idea to do a trial fix of the proposed repair method on a trial section of the building prior to doing the whole building. This helps contain the damages if the trial fix doesn't work. It will also serve as a basis for future comparisons, in terms of the level of quality expected.
Remember that when viewing EIFS for purpose of color judgements, the time of day and season makes a difference. The color of light hitting the surface is different at sunrise than at midday. Likewise, adjacent materials may bounce colored light onto the EIFS, giving the impression that the color is wrong when it really isn't. Thus when making color judgements, be sure to specify the time of day.
Last, if you are judging color and texture, as well as flatness, don't get suckered into discussing flatness with the light running parallel to the wall. Unless the EIFS is dead flat, which is virtually impossible to achieve, the slightest ripple will look like Mount Everest. Such problems usually occur at the beginning or end of the day when the sun is low, or at night. They can also occur when light shines down a wall parallel to the EIFS from above.
Back in the old days, when I worked for an EIFS manufacturer, we had the clever saying that "color is texture." While not technically accurate, it did make the point that the two aspects of "color" (namely color itself and texture) are interrelated. It's important to make that point when discussing such matters with people who hold themselves up to be oracles of all knowledge about what constitutes the right color.
