Grand River Rubble Stone Wall Restoration in Paris, Ontario

Heritage Brick and Stone was retained to stabilize and restore a century-old rubble stone wall along the Grand River in Paris, Ontario. The wall had sustained significant damage when a large mass of river ice struck its face during high water conditions, dislodging several large stones and leaving an area approximately the size of a small vehicle exposed and vulnerable to further collapse.

Project Planning and Approvals

The wall forms part of the foundation of a century-old solid-brick building. Although the property is not designated under the Ontario Heritage Act, the restoration was planned and completed in accordance with recognized heritage conservation practices—our standard approach when working with historic masonry.

The location presented several logistical and environmental challenges. Access to the damaged area required work platforms to be constructed at the river’s edge, while materials and equipment had to be transported from the roadway above. The work also needed to be scheduled during a period of low water levels and stable weather.

Before construction could begin, the proposed work was reviewed by the appropriate municipal building department, heritage committee and conservation authority. The wall was monitored throughout this period to confirm that the damaged area remained stable and that no additional deterioration occurred.

Access and Temporary Stabilization

Work commenced in late summer, when water levels were at their lowest and weather conditions were more predictable.

Custom tube-and-clamp scaffolding was erected along the riverbank and secured to the masonry wall for additional support. Loose stones surrounding the damaged section were stabilized using temporary timber framing, with individual stones carefully shimmed to redistribute the weight of the masonry above.

With permission from the municipality, a turning lane above the site was temporarily closed. A crane was then used to lower stone, mortar, tools and other equipment onto the work platforms below.

Rubble Stone Wall Reconstruction

The damaged wall was rebuilt in small, controlled sections to avoid leaving any large portion of the structure unsupported. Locally sourced stone was selected to closely match the colour, texture and general character of the original rubble stonework.

Spira-Lok stainless-steel helical ties supplied by Blok-Lok Limited were installed to provide additional anchorage between the reconstructed stonework and the original wall. These ties strengthen the connection while accommodating the natural movement that occurs in traditional rubble stone construction.

Compatible Heritage Mortar

The stones were laid using pozzolanic hydraulic lime mortar manufactured by King. This premixed mortar provides physical and performance characteristics compatible with traditional mass-masonry construction.

Using an appropriate lime-based mortar was essential. A mortar that is too hard or impermeable can trap moisture and transfer stress into the surrounding stone, potentially accelerating deterioration. The selected mortar allows the wall to manage moisture and movement in a manner consistent with the original construction.

Pozzolanic additives assist with strength development and reduce the damp-curing period normally required by traditional lime mortars. This was particularly beneficial on a weather-sensitive project where the wall needed to be reinstated efficiently without compromising material compatibility or conservation standards.

Project Outcome

The completed restoration stabilized the damaged foundation wall, reinstated its protective exterior face and maintained the character of the original stonework. Through careful planning, temporary stabilization, compatible materials and traditional masonry techniques, Heritage Brick and Stone delivered a durable repair suited to the building’s historic construction and challenging riverfront location.

Stair Tread Restoration at the Basilica of Our Lady Immaculate

Heritage Brick and Stone completed remedial restoration work on the monumental exterior staircase at the Basilica of Our Lady Immaculate in Guelph, Ontario.

Located at the head of Macdonell Street, the Basilica is one of Guelph’s most recognizable landmarks. Construction began in 1876, and the church was dedicated in 1888. Its twin towers were completed in 1926. The building is an exceptional example of High Victorian Gothic Revival architecture and was designated a National Historic Site in 1990.

Existing Stair Construction

The Basilica had recently undergone extensive interior and exterior restoration when Heritage Brick and Stone was retained to address deterioration affecting the lower section of its main exterior staircase.

The staircase consisted of precision-cut natural sandstone treads installed over a concrete block foundation. Each tread incorporated a raised lip at the rear, helping protect the horizontal mortar joint between adjacent stones from direct wear and water exposure.

Despite these design considerations, the bottom course of sandstone had deteriorated more rapidly than the upper steps. The relatively soft stone was particularly vulnerable to weather, moisture and exposure to winter road salt from the street below.

Selecting a Durable Replacement

The damaged sandstone treads required replacement, but the new units also needed to blend with the remaining natural stone.

Texture- and colour-matched precast concrete treads were selected to provide greater durability in this highly exposed location. The replacement units were manufactured to closely reproduce the appearance and dimensions of the existing sandstone.

Removing and replacing the lowest treads presented a significant technical challenge. The staircase was constructed as a series of overlapping units, meaning the lower stones could not be removed without carefully managing the weight and position of the surrounding treads.

Controlled Removal

The mortar joints surrounding each damaged tread were carefully saw-cut to separate the unit from the neighbouring stones. This reduced the amount of force transferred into the surrounding sandstone during removal.

Because the existing stone was relatively soft, Heritage Brick and Stone fabricated custom steel corner protectors for use around the tread edges. These protected vulnerable surfaces while power tools and lifting equipment were being used.

A vacuum lifting system was then employed to remove the treads. The equipment created suction through a large rubber gasket placed on the surface of each unit, allowing the stones to be lifted without drilling holes or wrapping them with straps.

This method provided controlled handling while minimizing the risk of damage to the remaining masonry.

Installation and Joint Finishing

The deteriorated treads were removed and replaced systematically, one unit at a time. Each new tread was positioned to within approximately 1/32 of an inch, maintaining consistent alignment across the staircase.

Once installation was complete, the joints between the treads were reinstated and tooled to match the surrounding masonry. Careful attention to joint width, profile and finish allowed the new work to integrate with the existing staircase.

Project Outcome

The completed restoration preserved the architectural character of the Basilica’s main entrance while improving durability at the most exposed section of the staircase.

By combining controlled removal procedures, specialized lifting equipment and carefully matched replacement materials, Heritage Brick and Stone delivered a precise and visually compatible repair suited to one of Guelph’s most significant landmarks.