Written by Stucco Champions — Southern California’s Authority on Exterior Plastering.

Installing Weep Screed Around Stairs: A Comprehensive Guide to Stepped Foundations

One of the most complex details in stucco installation is navigating a stepped foundation or staircase. Unlike a flat wall where the weep screed runs in a straight horizontal line, stairs require the flashing to "step" up and down with the concrete.

If done incorrectly, water becomes trapped at the 90-degree corners, rotting the stringers and framing behind the wall. This guide outlines the precise geometry and cutting techniques required to maintain a continuous drainage plane on uneven terrain.

1. The Geometry of the "Step"

You cannot install a single piece of metal diagonally. You must create a series of 90-degree turns that mirror the stairs.
The Components:
1. Horizontal Runs: These act as the traditional drain, sitting 2 inches above the tread (paving).
2. Vertical Risers: These connect the horizontal pieces. While they don't actively drain water, they provide the necessary depth gauge (7/8") and separation from the framing.

2. Preparation: The 2-Inch Rule

Code requires a 2-inch clearance above paved surfaces (concrete stairs) to prevent moisture wicking.
The Jig Method: Cut two small blocks of wood exactly 2 inches high. Use these as spacers on every stair tread. Rest the weep screed on these blocks to guarantee a perfect code-compliant gap without measuring every single time.

3. Installation Protocol

Precision cutting is mandatory. You will need tin snips (aviation snips) and a speed square.

Step A: The Horizontal Treads

Install all horizontal pieces first.
Measurement: Measure the length of the tread. Cut the screed to this exact length plus an additional 1/2 inch on the "uphill" side to allow for an overlap joint.
Fastening: Place the screed on your 2-inch spacer blocks. Check for level. Nail or staple the top flange into the studs/stringer.

Step B: The Vertical Risers

Once the horizontals are set, measure the vertical gap between them.
The Cut: Cut a piece of screed to fit this vertical space snugly. You may need to trim the bottom flange at a 45-degree angle to mate cleanly with the horizontal screed below it.
The Result: You should have a continuous metal line zig-zagging up the stairs.

4. Why Not Angle It?

We are often asked: "Can't I just run one long piece of screed diagonally up the stairs?"
The Answer: No.
1. Code Violation: It is impossible to maintain the 2-inch clearance on a diagonal. At some points, the screed will touch the concrete; at others, it will be too high.
2. Aesthetics: A diagonal line against a stepped foundation looks sloppy and unprofessional. The "Stepped" installation mirrors the architecture.

Conclusion: Precision Protects the Frame

Staircases are high-risk areas for water intrusion because water splashes off the steps onto the wall. By meticulously installing a stepped weep screed system with proper clearances, you ensure that this splash-back drains out of the wall rather than soaking into the framing.