With historic or landmark structures, special considerations may arise during the investigation. In order to avoid high-cost change orders and delays caused by unforeseen conditions, the design professional may need to research original construction documents and records of earlier repairs and building alterations. Onsite observations complement this evaluation, as portions of the original documents may be unavailable, and building construction can deviate from that shown on plans. Test cuts, probes, photographs, and laboratory analysis may be part of this investigation.

If the building is a Canadian Register property, provincial or municipal heritage site, or significant landmark, accepted treatment practices—such as those found in The Standards and Guidelines for the Conservation of Historic Places in Canada—must be addressed as early as possible in the project. If approval from the local authority having jurisdiction (AHJ) over historic properties is required, the process can take time, so the design professional should research the necessary codes and regulations and initiate the process of obtaining required variances and endorsements during the initial investigatory phase.

Once conservation standards and regulations have been taken into account, probable causes have been considered, and drawings and construction documents have been examined, a brick rehabilitation and maintenance program can be designed to meet the needs of a historic or landmark building. Generally, this includes establishing a scope of work, phasing, and budgeting.

Organizing the work
In undertaking a brick repair, replacement, or repointing project, the job must be planned carefully and logically. Stabilizing the structure is the priority. Any hazardous conditions identified during the investigation, especially those posing a danger to public safety, should be addressed immediately. Loose or severely deteriorated brick must be removed or held in place to prevent accidents.

Any such stabilization measures, however, should lay the groundwork for the rehabilitation effort. Care must be taken not to harm the structure or to increase costs of subsequent work. For instance, it is common practice to secure dangerously loose brick with netting or screening until a more permanent solution can be implemented. However, if improper anchorage was used in previous construction, removal may be sufficiently difficult as to further damage the building envelope.

Prior to the start of masonry remediation, underlying causes of water penetration must be uncovered and corrected, or the work done will waste time and money. The mason should be skilled enough to provide commentary on discovered site conditions that may not have been apparent from the design professional’s observations. Proper sequencing can also help ensure both new and existing mortar weather similarly for better matching.

If budgeting allows, it makes economic sense to do all needed repairs at the same time to avoid incurring additional set-up costs. Scaffolding, sidewalk bridging, and other protective measures are expensive to take down and resurrect, and tenants will experience less disruption with only one construction period. Ideally, related roof and structural repairs should take advantage of scaffolding erected for brick work.

In larger projects, correct phasing is essential to avoid damage to newly repaired sections when preparing the next portion of the work. For example, if cleaning is part of the program and the mortar joints are watertight, it makes sense to postpone repointing until after the building is cleaned. For cases where mortar is eroded badly enough to allow water penetration, repointing would need to be completed first.

A prime consideration in planning the repointing or replacement phase of a masonry rehabilitation project is the weather. Masonry surface temperatures should remain fairly moderate, so beginning the work in very cold or very hot, dry weather is not advisable.

Without detailed and exacting construction documents, there is no assurance the often extensive time required to prepare and restore historic brick structures will be well-spent. Skilled hand labour and custom mortar mixes may be needed to appropriately repoint or rebuild deteriorated masonry. While a thorough investigation is essential to identify underlying problems and prioritize repair work, only specific construction documents and drawings can provide details of proposed solutions. Onsite project representation and construction administration can then help ensure the brick rehabilitation program is being implemented as designed.