Flitch Plates

What are flitch plates?

The term ‘flitch’ refers to a plank of wood or timber which has been laterally cut from a tree trunk. Its origins stem from the word ‘flesh’, originally referring to a slab of bacon cut into strips lengthwise. In the same manner, a wooden beam underwent flitching, a process that involved cutting it lengthwise. One of the resulting halves was then rotated 180 degrees both longitudinally and laterally, ensuring the separation of any defects.

During the 18th century, when steel beams were not readily accessible, pine beams were flitched using a hardwood like oak. As affordable steel became available, flitch beams emerged as a cost-effective method to reinforce long-span wooden beams while occupying less space compared to solid wood. 

How are flitch plates used in structural steelwork?

They are used predominantly in the construction of old wooden structures, acting as good reinforcement to underlying timber. Flitch plates are also commonly used in houses, decks and loft conversions with a prevalent wood base but with the added structural integrity of steel support as well as renovation projects.

A steel flitch beam usually slots between two wooden beams bolted together. Further layers of wood can be applied to increase the strength of the flitch plate, as well as additional layers of steel.

The flitch plate is drilled, typically in a staggered, zigzagged formation, to increase the sturdiness of wooden joists. The wood is bolted to the steel plate, which increases the durability of the wood and allows it to span for greater distances than solid timber. Flitch beams are significantly stronger than solid wooden beams and require substantially less depth than these beams.

How Flitch Plates Can Benefit You

One other huge benefit of using flitch plates in building work is their low cost. As well as being supremely lightweight, they are an excellent alternative to solid structural steel beams, costing far less per metre on average.

Flitch beams remain a versatile, bolstering beam type that doesn’t compromise any fundamental works. They offer a host of benefits to the construction industry, enhancing structural strength by combining steel’s resilience and wood’s versatility. This provides increased load-bearing capacity, reduced deflection, improved stability, and simplified construction processes. They also enable efficient designs, cost-effective solutions, and overall structural integrity, making them a valuable choice for various construction projects.

Flitch plates promote sustainability by utilising timber, a renewable resource, in combination with steel. This union allows for efficient use of materials, reducing waste and environmental impact. The combination also helps minimise deflection or bending, ensuring that the beam remains rigid and stable under load. This is particularly beneficial for applications where minimal deflection is desired, such as floors, roofs, and bridges. 

Feel free to contact us if you have any questions or would like to know more about flitch plates.