Putting a pergola on a sloped yard

Both makers want a flat, solid base, so a slope means you build one first: a poured pad or a deck. The kit doesn't fix the slope.

What the makers require

• Hanso: solid, level concrete at least 4 inches thick, or paving, or tile on concrete pads, or decking (Hanso spec sheet).
• Sunjoy: wood deck or concrete, not soil. Anchors not included (manual).

Dirt, grass and gravel don't qualify under either.

Your three routes

1. Pour a level concrete pad. Cuts into the slope on the high side and builds up on the low side. Needs the 4 inches Hanso names at the thinnest point. A concrete contractor can quote this.
2. Build a deck. It levels the floor and gives you a base the makers accept. Make sure the deck is built to carry roof posts in wind, not just people. We haven't researched deck framing and won't guess.
3. Move it. Look for the flattest spot in the yard first. Moving 20 feet can save a pad.

Ask before you spend

• Does your town need a permit? Many do for a roofed structure, and the size or height that triggers it varies. We haven't looked up yours.
• Where is the water going? A pad on a slope can push runoff toward the house or a neighbor.
• What's under the ground? Call 811 before digging. (That's the US utility locating service.)

What we don't know

We found no maker guidance for slopes other than "level base." Anyone who tells you a kit "adjusts to a slope" is saying something we couldn't back up from the manuals.

Links

• Hanso Pro+ aluminum pergola kit
• Sunjoy 12x12 Roanforth hardtop gazebo

Read Nov 4, 2026.