How to Hide Ductwork in a Cathedral Ceiling

Prepare the area for painting. Lay drop cloths on the floor and over furniture to protect it from dripping paint. Paint the ceiling and duct work with a white primer paint. You want a base paint for a trompe l’oeil scene.

Draw out your trompe l’oeil scene for the cathedral ceiling and ducts. Look at other trompe l’oeil paintings and decide on whether you want a sky scene, a landscape or even an abstract painting. Think of your cathedral ceiling as your fifth wall, one that can be a work of art. Make the ducts a focal point of the ceiling by drawing twining tree branches, flowers or railings on the ducts. This will give the finished trompe l’oeil a feeling of three dimensions

Trace out your final drawing on graph paper measuring every graph box as one foot on the ceiling. This will help you trace the drawing on the ceiling.

Sketch the final drawing on the cathedral ceiling with charcoal, using the graph dimensions, or project the final drawing on the ceiling with an art or school projector and trace the large image onto the surface.

Start painting the tromp l’oeil with acrylic paints. Work with one square foot at a time painting in darker shades first. Since your initial paint layers are less precise and only meant to add the shades and color tones, use larger brushes, gradually decreasing the size of the brush as the work becomes more precise.

Paint one entire layer over the entire cathedral ceiling, followed by another lighter layer.

Make defining lines in black or dark umber colors, after you cover the painting in the first and second layer. This will give the different sections a more defined look. Continue adding lighter layers and highlights in the different areas. Add light tones in layers gradually adding smaller and precise highlights at the end with finer brushes.

Add the necessary paint colors on the ducts, using smaller brushes, as this area should be more intricate than the entire ceiling, because you are emphasizing the relief form of the ducts.