Masonry allows for unlimited architectural expression. The shapes, sizes, colors, textures, and finishes of the units and joints can be combined in endless variations. Minor fluctuations in shade and texture impart depth and character to masonry structures. And each wall is unique. But within that context, there has to be some uniformity.
Mockups are sample panels made using the same materials, techniques, and personnel that will be used on the project. Constructed ahead of time, they help all involved parties understand what can be built and how it will appear. Serving as a tool of comparison to judge finished work, they may be stand-alone panels that will be removed at project completion or they may be part of the structure, preferably in a less visible location. The second option saves time and money.
Achieving acceptable appearance of mortar joints on a project requires three key steps:
- initial agreement between the owner or his representative and the contractor or mason on what constitutes desired appearance
- an understanding by both of the inherent limitations of the system
- careful control of influencing variables by the contractor and mason
- Construct the panel in a safe area. Retain for future reference if necessary.
- View the masonry together. This assures that purchaser (owner) and provider (mason) are examining the masonry under the same lighting and environment.
- Optimize the viewing environment. View under strong but indirect sunlight if possible.
- Evaluate as a whole. Consider the overall appearance of the masonry as basis for evaluation. Usually this entails observation from a distance of approximately 20- to 30-feet
- When questions arise, examine the mockup closely. The cause for differences in appearance observed from a distance can often be determined by close inspection of the masonry.
- Talk about it together. Evaluation of appearance is truly subjective, but most people can agree on the general aspects of what they like and don’t like.
The masonry sample panel or mockup is an important means of establishing agreement between purchaser and provider on what is expected and what is achievable. Depending on the complexity of the project, the role of a masonry sample panel or mockup can go beyond providing a means for evaluating the appearance of masonry.
However, establishing appearance criteria for the project is certainly one of the basic reasons for constructing, approving, and retaining sample panels or mockups. In addition to following the general guidelines for evaluating the appearance of masonry previously mentioned, the mason contractor should be certain that the panel is indeed representative of what can be achieved on the project. The materials, batching and mixing procedures, level of workmanship, curing, and cleaning procedures used to construct the sample panel should be consistent with what will be provided in construction of the project. This requires planning on the part of both the owner and the mason contractor, to provide adequate time for the mortar to cure, for the panel to be cleaned, and for the project to dry prior to evaluation of its appearance.
Honest discussion between the owner or the owner’s representative and the mason contractor is required to assure that a clear understanding is reached on what appearance criteria are reasonable to expect in the completed masonry. For example, the mason may need to explain how the combination of the masonry unit‘s suction characteristics, sand quality, mortar type, and tooling requirements being used on a specific project affect consistency of texture and shade of mortar joints. The owner or the owner‘s representative may wish to emphasize concern that precautions such as covering units and walls are taken during construction to minimize variability in the appearance of mortar joints.