Proper repointing is the keystone of the MPS organization—and the service we consider most important to our customers. Why? Unfortunately, it’s due to the fact that so much improper repointing is being done every day. When done incorrectly, repointing is of little or no value to a building owner. In fact, ineffective repointing can actually decrease a building’s value as it begins to quickly deteriorate, often leaving masonry walls less able to resist moisture intrusion than before repointing efforts. Improperly executed, repointing will not only detract from a building’s appearance but may also cause unnecessary physical damage.
Proper Repointing
Proper repointing of deteriorated or improperly maintained mortar is one of the most useful preservation tactics that can be applied to buildings of historical or architectural significance. Done correctly, repointing will restore a building’s visual and structural integrity—and ensure lasting resistance to wind-driven rain. Through thorough testing, careful planning, and detail-focused execution, MPS provides our clients with unparalleled repointing services.
The process of removing deteriorated mortar from masonry wall joints and replacing it with new mortar, proper repointing is based on a thorough process involving expert problem analysis, mortar matching, mortar mixing, scheduling, and execution. MPS also employs a thorough before-and-after testing system to ensure the overall effectiveness of each of our repointing projects.
Problem Analysis: Before any repointing work is initiated, MPS will determine the root cause of all building envelope deficiencies. Only when it is certain that repointing is the best course of action will work begin.
Mortar Matching: All repointing work must be both physically and visually appropriate. MPS conducts thorough examination of masonry units—brick, stone, or terra cotta—to determine the information needed to develop an appropriate mortar mix and application strategy.
Mortar Mixing: In creating a repointing mortar that is compatible with existing masonry units, MPS focuses on a mix that matches the historic mortar as closely as possible. New mortar is carefully created to match historic mortar in color, texture, and tooling; to have greater vapor permeability than both the historic mortar and the existing masonry units; and to be softer in compressive strength than the surrounding masonry units.
Scheduling: Due to the time-consuming nature of the repointing process, MPS ensures that cost-effective scheduling is utilized within each of our repointing efforts. Seasonal aspects are always considered, as are scaffolding issues and the repointing’s relationship to other areas of building repair.
Execution: In executing a proper repointing effort, MPS utilizes a number of proven methodologies:
- Test Panels: Preliminary test panels establish a benchmark for subsequent repointing work.
- Joint Preparation: Old mortar is removed to a depth of at least 2-1/2 times the width of the joint to ensure a high-strength bond. Mortar is removed cleanly from all masonry units, leaving square corners at the back of all cuts. Before filling, all joints are rinsed with water to remove any loose particles.
- Joint Filling: Deeper areas are filled first, compacting new mortar in several layers. When the final layer is sufficiently hard, the joint is tolled to match the historic joint. If bricks or stones have worn edges, final mortar is recessed slightly away from the masonry face.
- Testing: Thorough testing before and after repointing means we know our efforts have succeeded. MPS was using nationally recognized repointing testing standards before anyone else in the industry.
Repointing Guaranteed to Perform
Repointing shortcuts result not only in the diminishment of a building’s character but also in a job that looks bad and will require future work. MPS’s approach to repointing results in a job that will last for decades to come. Our precise, no-excuses repointing guarantees a long life for mortar joints and walls—and is the key to long-term preservation.
