Wood Substitute for a Metal Trellis Beam

Lumber Types

• Manufacturers use metal, and particularly steel, for structures like trellises because of its strength and durability. Galvanized or stainless steel, in particular, exhibits a high degree of rust resistance. When it comes to substituting a metal trellis beam with a wooden one, choose lumber with similar qualities, including strength and weather resistance, to those of the metal -- because you don’t want your wooden beam collapsing from weight stress while the rest of your trellis still stands. Find the tensile strength of the metal in your trellis by contacting its manufacturer. Compare this to the tensile strength of various types of lumber, plywood and laminate boards to find the best fit. You can find charts of the qualities of woods, lumber and metals online or at a local library.

Designing a Replacement

• Once you decide on a wood type and purchase your raw material, design a wood substitute for your metal trellis beam. You need measuring tape and an angle-measuring tool like a compass for this. Measure the length, width and height of a rectangular solid bar, or the length and circumference of a cylindrical bar. Measuring any angles other than the standard 90-degree angles found on rectangular beams with your compass. Create a scale drawing of your metal beam, including information on angles and dimensions.

Working with Wood

• Working with wood ranges in difficultly from extremely simple to very complex. For instance, when replacing a rectangular metal trellis beam with a laminate wood beam, you need only purchase a beam of the same height and thickness and cut it to length with a saw. However, replacing a beam with curved elements requires shaping wood, a relatively difficult task that requires tools like files, rasps and gouges. Getting precise angles with these tools can prove especially difficult to inexperienced hands. If you possess no experience working with wood, you can hire a local carpenter or pay a lumberyard to shape wood to specific dimensions and angles for you.

Substituting Beams

• The difficulty of substituting a beam in a trellis depends on the manufacturing process used for the trellis and which beam you want to replace. On a welded trellis, you need welding equipment to melt the joints of the beam you want to replace. Replacing a beam in the middle of a tightly welded structure may prove too complex to be practical. However, you can remove a beam at the side or top of a trellis with relative ease when you have the right equipment. You must use an adhesive approved for use with wood and metal to adhere a wooden beam to a metal trellis. Use waterproof sealant around the joints for extra protection. You can paint your wooden beam the same color as the trellis metal for an even look. For safety reasons, avoid tampering with a trellis that could injure people if it collapses.