How to Install LED Wall Washer: Step-by-Step Checklist

Most wall washer failures we investigate are not manufacturing defects — they are installation issues. This checklist covers the steps that cause the most trouble in the field.

Step 1 — Verify the mounting substrate

Before anything is ordered, confirm what you are fixing into: concrete, steel structure, curtain wall mullion or pre-drilled cladding. Brackets and anchors differ for each. For curtain wall facades, agree the fixing detail with the facade contractor in writing — drilling into structural mullions is often prohibited.

Step 2 — Plan the mounting line and offset

The offset distance from the wall determines the wash height and the uniformity. Mark the mounting line with a laser level rather than measuring from the ground, because facade surfaces are rarely perfectly straight. A 5 mm variation in offset translates into a very visible variation in the light band.

Step 3 — Fix the brackets, not the fixtures

Install all brackets first, then attach fixtures. This lets you correct the level and alignment while nothing is heavy or awkward. Leave the aiming screws loose until commissioning.

Step 4 — Protect every cable entry

• Use IP-rated connectors, not glands plus tape.
• Form a drip loop so water runs off the cable rather than into the fitting.
• Never leave connectors resting in a position where water can pool.
• Keep the data cable and the power cable physically separated to avoid interference.

Step 5 — Power and voltage drop

For DC fixtures, calculate voltage drop across the run. Long runs cause the far end to dim and shift colour. Inject power at intervals and use a cable gauge that keeps the drop under about 3%.

Step 6 — Aim and commission

Aim fixtures at night, from the viewing position. For facades, walk the full viewing distance and check for scalloping between fixtures. Set the dimming curve and scene presets at this point rather than leaving them at full output.

Step 7 — Document

Photograph the aims, record DMX addresses and universe assignments, and leave a schedule inside the control cabinet. Future maintenance will be dramatically easier.