In construction and renovation projects, it is sometimes necessary to reinforce or strengthen a beam that will bear weight. There are several methods for doing so, and few are more versatile and effective than using a flitch beam. This is comprised of two wooden beams joined together by a steel plate–called a flitch plate–to reinforce and multiply the strength of a singular beam. While the use of these beams has largely been replaced by composite lumbers that are just as strong but cheaper and easier to install, they still has many uses and are a common technique, particularly in renovation projects.
In situations that call for a beam that can transfer load over longer distances,a flitch beam can be particularly useful. The construction of a roof would be an example of such a situation. A flitch beam can bear a much heavier load than a simple wooden beam, so it is a good choice for such applications. It is also lighter than a steel beam, which adds to its advantageousness in home projects. Because the beam is made of wood as opposed to metal, it can still be connected to existing wooden structures using screws or bolts with less effort than would be the case with a steel beam.
To construct a flitch beam, two beams must be cut to length. Then, a prefabricated flitch plate is sandwiched between the two beams. Finally, the three parts of the composite beam are bolted together, which can be done off-site or on-site, depending on the size of the project and the availability of resources. One of the drawbacks of this technique is that the plate often has to be prefabricated; if it is not, it can be something of a chore to install on-site, though it is by no means impossible. Some experts have moved away from flitch beams because of the high labor costs associated with installing them, opting instead for engineered composite lumber studs and beams to accomplish the same goal.
The flitch beam is a versatile method, too, because the strength of the beam can be increased by adding more flitch plates and wooden beams. The more plates and beams are added, the stronger the beam will be. Again, this is particularly useful in renovation scenarios where an existing structure must be reinforced. Further, because this type of beam is stronger than a normal beam, the flitch beam requires less depth than a regular beam.