Concrete Thickness: The concrete slab should generally be 4–6 inches thick to provide adequate support for the pergola.

Condition of the Slab: Ensure the slab is in good condition, free of cracks, and not over expansion joints or too close to slab edges.

Drainage Slope: A moderate drainage slope (1/8"–1/4" per foot) is acceptable. The pergola must be installed level and plumb even if the slab is sloped.

Surface Assessment: Verify that the installation surface is square and level. If the surface is uneven, use appropriate shimming or leveling techniques at the base plates to ensure the pergola posts are plumb and the frame is level.

Measurement Checks: Measure distances between the pergola legs at the top, middle, and bottom, as well as the diagonal distances from foot to foot. Adjust as needed to achieve a square installation.

Anchoring to Existing Concrete: Wall-mounted pergolas, such as the Hansø Apex model, can be anchored to an existing concrete patio if the slab meets the general requirements outlined above. Verify the slab’s thickness and construction before proceeding.

Leveling and Alignment: Proper leveling and alignment are crucial for smooth louver operation and effective gutter drainage. Use tools like a spirit level and measuring tape to confirm accuracy during installation.

Rechecking Measurements: After initial assembly, recheck all measurements to ensure the pergola is square and level. Adjust or reinstall components as necessary.