Design features of EIFS – aesthetic reveals

The fact that Exterior Insulating Finishing Systems are largely comprised of foam bodes well for them with regards to their endless design possibilities. This foam can be cut, grooved or altered to create features on any EIFS wall, and one of these features is the aesthetic reveal or aesthetic joint. The former term is preferable, as the latter term implies it is a joint. While resembling a joint, aesthetic reveals are not functioning joints.

Aesthetic reveals versus foam shapes

Foam shapes are chunks of lamina-coated foam that attach onto EIFS to create a pattern or design. Aesthetic reveals are not added on, they are merely standard EIFS that has had shapes or grooves cut into or taken out of the expanded polystyrene insulating foam component.

Problems with aesthetic reveals

Aesthetic reveals are not overly problematic, however cutting pieces out of the insulating foam can have slight repercussions. The first problem that arises is the most obvious – removing or thinning the insulating foam lowers its insulating capabilities depending on the size of the pieces being cut out, but this issue is still relatively small.

The second problem that can arise with using aesthetic reveals is a bit more serious – the creation of an over stressed, thin and weak point on the wall. If the building is constantly shifting, the aesthetic reveal may not be strong enough to handle it and slight cracking of the lamina may occur.

Solutions to the problems with aesthetic reveals

As previously stated, problems regarding lowered energy-efficiency in relation to aesthetic reveals on an EIFS wall are slight. It is more than likely anyone using EIFS for its “green” appeal will not notice a change in their energy bills whatsoever.

The second and more serious problem, possible lamina cracking because of over stressed weak spots, can be rectified rather easily. More common aesthetic reveals are square-shaped with sharp, flat edges. The lower edges especially can become easy harbourers of dirt and water which can then lead to mildew issues later on, as well as having the problem of not responding well to stresses from the shifting of buildings. If these edges were instead rounded and sloped, the potential cracking and dirt issues can be resolved.

Using the proper tools for the job

Special trowels are available for setting up aesthetic reveals. Using these trowels will allow for easy installation, and they typically have duller edges. These duller edges are useful for not accidentally cutting or nicking the reinforcing fiberglass mesh, which will significantly lower its strength and structural integrity. This is especially important if the reinforcing fiberglass mesh does not come with a protective plastic coating.

Knives and routers can be used to create the aesthetic reveal grooves, but this can also lend a hand to the problem of aesthetic reveals looking “handmade”, as well as additional unintended pieces of foam breaking off and falling all over the ground. Because expanded polystyrene foam has a relatively low melting point, heated wires can be used to make a very smooth and uniform groove.

Final coatings and the aesthetic reveal

When cutting the grooves out of the foam to specified measurements, it’s extremely important to remember that the groove will eventually be covered with reinforcing fiberglass mesh as well as the finishing lamina. If this might add a considerable amount of material to the finished groove, the groove must be made a bit larger to compensate.

The choice of mesh used in the aesthetic reveal is also important. One may assume that since aesthetic reveals are considered to be a weaker point in the EIFS wall that heavier mesh could be used, but heavier grades of mesh are much more difficult to press into tight aesthetic reveals. Light to standard weights of reinforcing fiberglass mesh should be used in the cases of most aesthetic reveals.

Layout and design

Because aesthetic reveals are purely that – aesthetic – there are a few important considerations to undertake when installing them to ensure they don’t interfere with the function of the EIFS wall.

  • Aesthetic reveals over joints should be avoided at all costs. This can lead to cracking.
  • Aesthetic reveals placed in areas where mesh will be overlapping is also something that should be avoided, as it will be difficult later to create a clean-looking groove.
  • When installing the mesh component into the aesthetic reveal, it’s a lot easier to give the aesthetic reveal its own strip of mesh than attempt to unroll a layer of mesh over it, and later attempt to cram the mesh into the groove.
  • Aesthetic reveals are not constructed in the same manner as an expansion joint, and should never be used as such. Expansion joints serve a function when it comes to allowing the building envelope to shift, whereas aesthetic reveals are for looks only.
  • When aesthetic reveals approach flashings or other components, they can act as an access tunnel for water to penetrate the component. When an aesthetic reveal approaches something in this manner, the space where both components meet should be carefully caulked.
  • The minimum specifications for foam thickness can vary, but if one wants the foam inside of a groove to be thin when compared to the rest of the EIFS, the rest of the EIFS might have to become thicker. To obtain the look of a deep groove without increasing the thickness of the overall foam, the groove of the aesthetic reveal can be painted darker to achieve a similar-looking result.

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