Exposed wooden beams are a desirable element in many homes. However, wooden beams can be expensive to purchase and difficult to install. For this reason using faux wood beams, often made out of styrofoam, is a popular alternative to real wooden beams. Carefully constructed and installed styrofoam beams can be hard to differentiate from wooden beams, while at the same time being much cheaper and easier to deal with. Homemade styrofoam beams are a great project that can be used to add a historic, classic or simply pleasant effect to a room.
Determine the length and diameter of styrofoam you'll need for your beams. Styrofoam often comes in cubes, with a 5- or 6-inch diameter cube being an acceptable beam width for most projects.
Cut the styrofoam down to size. Depending on what type of styrofoam you have, you may or may not have to trim it. Place the styrofoam blocks back-to-back until they reach the desired beam length and then make any necessary cuts of protruding or excessive styrofoam.
Add some wood-like qualities to the styrofoam. Use a knife or box cutter to cut slivers into the styrofoam. Use a hammer or chisel to lightly indent the styrofoam. Use a nail or other sharp object to add pockmarks or other small indents in the styrofoam. Practice your decorating technique on a practice piece of styrofoam before applying it to the real beam.
Paint the styrofoam beam with two coats of sculptural arts plastic varnish to seal it and create a hard outer layer. Allow the coats to dry thoroughly.
Stain the styrofoam beam with the desired colour of wood you want it to resemble. Make sure to paint the bottoms of the beams as well as the sides. It's also a good idea to practice this step before applying it to the final beams. See the resources section for more information on staining styrofoam beams.
Use wood glue to adhere the beams to their intended surface. Cover one side of the beam with an even layer of glue and let it dry for a few minutes until the glue gets a little tacky.
Apply a coat of wood glue on the surface where the beam will go while the glue on the beam is drying. Attach the beam to the surface and hold it for several minutes before slowly releasing. Check back every five minutes for a half hour to make sure the hold is still firm.