Carving Faux Beams From Large Blocks of Styrofoam

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  • 2-8 hours
  • Beginner
  • 125-300
What You'll Need
Plastic foam
Measuring tape
Drawing paper
Fine-tooth saw
Wood sample
Handheld, dremel-style rotary tool
150-grit sandpaper
Shop vacuum
Latex paint
Construction adhesive

You may like the look of ceiling beams in your home, but if no beams were built into the original construction you can substitute faux beams as an easy DIY. With a little practice, some dependable instructions, a few blocks of plastic foam, and some simple tools and materials, you can make faux beams look real.

Step 1 - Create Your Beam Shapes

Decide how wide and deep you want your faux beams. Measure and mark those dimensions onto your blocks of plastic foam. Lay your foam on a clean surface and, using a carpenter’s square, draw the lines along which you’ll cut. Then, use a fine-tooth saw to cut your beam from the block.

Step 2 - Create Faux Wood Grain

Some woods, such as walnut, have prominent and distinct grains. Others, such as mahogany, have a grain that is finer and smoother. If you want your faux beams to look real, you have to simulate some form of grain on them.

To do so, examine a few sample pieces of wood. Study their grain patterns and decide which you prefer on your beams. Using a notebook and pencil, draft some patterns until you’re satisfied with one. Try to include characteristics you have seen in your samples—knots, converging lines, waving lines, etc.

Step 3 - Draw Your Pattern on the Styrofoam

Use a permanent marker to draw the wood-grain pattern on your faux beam. Be sure to continue your pattern onto the adjacent sides of the block. Step back occasionally to make sure your pattern looks as good from a distance as it does up close.

Step 4 - Carve Your Faux Beams

Use a Dremel rotary tool with a shaping-stone bit to begin carving your beam’s edges, slightly rounding them to resemble the edges of a wood beam. Try to recreate the naturally uneven edges of wood. When you’re finished cutting, begin creating the grain lines by cutting them in with your rotary tool. They should be about 1/16 to 1/18-inch deep.

Step 5 - Paint

When you’re finished carving, use 150-grit sandpaper to smooth out any rough surfaces or edges. Remove any dust or debris with a soft brush or shop vacuum.

Apply your paint, using wide brushes for broad areas, small ones for the lines. Try to match the colors in your wood samples. Usually, you’ll need to use at least four shades of the same color to mimic the appearance of wood. Cover your beam with the primary color, usually a darker brown, and then, when this paint has dried, work in the lines with lighter shades.

Step 6 - Install

Apply construction adhesive to the top of the beam and to the ceiling where the beam will go. Press the beam in place and secure it with masking tape until the glue is set. Make sure to use a glue that is safe to use on foam.

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