WHAT TO TAKE AWAY
- Confirm what is causing the surface movement.
- Coordinate hardscape design with retained-tree assessment.
- Public sidewalks and trees require a separate City process.
Treat the surface and tree as one project
A lifted patio edge or uneven walkway is usually discovered at the surface, but repairing it may involve the soil and roots underneath. A paving contractor and an arborist answer different parts of the problem. One assesses the structure and proposed surface; the other considers the retained tree. Take photographs showing the uneven area, the tree and the route people use. Mark the private project boundary on a sketch. This helps avoid a quote that fixes the visible slab while leaving the tree implications unexamined.
Verify the cause before naming the remedy
Do not assume every uneven slab has a root immediately beneath it, or that cutting a root is the only repair. Ground movement, drainage and installation details may also need investigation by the appropriate contractor. Explain what you have actually seen and what is still an assumption. If a root is confirmed, ask whether the design can accommodate it. The City of Calgary has discussed alternative sidewalk approaches where root removal risks tree health or stability; that illustrates the importance of considering the tree and the surface together.
Agree on the investigation boundary
Opening the area to inspect it can itself disturb roots or buried services. Set limits on exploratory work and identify what happens if large or unexpected roots are found. Utility information is part of the plan even when the work appears shallow. A marked locate does not establish line depth, and customer-owned systems need separate attention. Tell both specialists about irrigation, lighting and outbuilding services. Their investigation plan should fit the site rather than relying on the assumption that a patio area is clear ground.
Compare the alternatives in writing
A useful proposal identifies the repair footprint, any layout change, materials, handling of roots and the finish at adjoining surfaces. If selective root work is recommended, keep its arborist assessment linked to the paving scope. If a route can move, compare the usable space gained and the effect on other yard functions. Avoid promising that one repair will prevent all future movement. Ask what maintenance or monitoring is expected, and whether the proposal addresses only a local hazard or the broader condition of the hardscape.
Keep public work separate
A public sidewalk or boulevard tree is not an extension of the private patio job. Confirm ownership before altering either. Calgary Urban Forestry can help with tree ownership inquiries, while a public sidewalk concern should follow the City's reporting process. For private work, document the condition before starting, preserve agreed protection areas and inspect the finished transitions with the contractor. Keep the records for future maintenance. The living-root guide and utility-locate guide explain the two questions to resolve before opening the ground.
A practical question to settle
Ask who will review the opened area before the new surface is installed. If the paving contractor finds roots that were absent from the initial photos, the agreed pause and assessment should happen while they are visible. Covering first can make the next decision harder to explain.
Sources & local context
Requirements and waste services vary by municipality. These sources support the guide; confirm the details that apply to your actual site.
- Avoiding Tree Damage During Construction ↗International Society of Arboriculture · Arborist planning, critical root zones, soil disturbance, compaction and machinery damage.
- Contact Urban Forestry ↗City of Calgary · 311 inquiries about tree ownership, public-tree concerns, stumps and development protection.
- Click Before You Dig: Homeowner Overview ↗Utility Safety Partners · Alberta locate requests, utility responses, private lines and safe work near markings.
- Tackling tree tripping hazards: one rubber sidewalk at a time ↗City of Calgary · Historical 2019 example of considering alternatives to root removal when repairing sidewalks; not a current municipal installation offer.