Beam And Block Flooring: Disadvantages And Advantages

Some countries refer to beams and blocks as ribs and blocks or lintels and blocks. A range of concrete or masonry buildings can be constructed with in-situ, suspended concrete floors (ground or upper) using this technique, and it is increasingly being used in residential construction.

Beam and block flooring has been used in the UK for many years, in domestic and commercial construction, and is beginning to be seen more in Australia.

It is easy, quick, and cheap for anyone to build a beam and block floor, requiring no special construction skills, they are also highly durable and solid. It is particularly suited to first-floor structural applications where it can replace traditional suspended timber joists and engineered wooden joists.

It is an important decision to determine whether a block and beam floor system will be installed or not as there are a number of things to consider. Almost every flooring system has some type of advantage or disadvantage. The use of block and beam construction, also known as the bison beam, has a number of advantages over traditional solid hardwood floors. If you know how to install it, you can complete the project in a very short period of time.

Beam And Block Flooring – A Brief Explanation

Beam-and-block floors are composed of clay or concrete blocks (known as ‘pots’) that are supported by parallel, usually prefabricated, prestressed concrete beams or ribs. Once the blocks are infilled between the parallel beams of concrete, a continuous working surface is created. Several methods can be used to accomplish this. The first type of T-beam is shaped so that its lower part is supported entirely by continuous ledges. An average beam thickness of 130mm is used, and beam spans of up to 6m are possible. According to the span, the shape of the block, and loading requirements, the beam profile will differ. The infill blocks are laid quickly once the beams are in place and supported at each end: as long as the blocks are readily available, they can be dropped into place every five to ten seconds. A typical specification requires a block to have dimensions of 440mm x 215mm x 100mm, a minimum compressive strength of 3.5N/mm2 or 7N/mm2, and be able to support at least 3.5kN in transverse load. As the beam is supported at each end, whether within load-bearing walls or external perimeter walls, no shuttering (support) is required on the underside of the floor. Once you have installed the filler blocks, you will have a smooth working surface on which you can do any subsequent work without risk of injury. To fill voids, treat the surface with a sand and cement grout to deter insects and vermin and improve airtightness.

Choices For Floor Finishing

Afterward, either a poured structural concrete top (or screed) or timber deck flooring (e.g. flooring grade OSB, ply, etc.) can be applied. A structural concrete topping may be placed over insulation slabs and a damp-proof membrane (if the floor is on a ground floor) or vapour barrier if it is a first floor. Steel mesh reinforcement can also be incorporated into the topping to increase its strength. The floor will be able to handle the full weight of its contents without the topping once it has cured. They can be used quickly in creating a usable working platform because the precast beams are easy to assemble. Cross-sections of beams can vary depending on the manufacturer. Furthermore, a closed soffit can be produced, in which case a relatively continuous soffit will be created, or an open soffit may need to have an applied ceiling: this might take the form of plaster or enclosure by a suspended ceiling. A rigid insulation slab can be used instead of concrete hollow blocks when a lightweight, insulated floor slab is needed.

Pros And Cons Of Beam And Block Flooring

Floors made of beams and blocks offer the following advantages:

  • Handling is easy
  • Unskilled labour can be utilized
  • Concrete floor systems that are durable
  • Suspended floors can also be hung from these systems
  • Because beams and blocks are manufactured off-site, it is economical
  • As hollow blocks do not need time to cure as poured concrete slabs, they are often lighter and quicker to construct than in situ slabs
  • It can be used for suspended floors on sloped sites, for ground that has poor bearing capacity, for sites with high water tables, or for sites with toxic chemical contamination.
  • This method does not depend on the weather, reducing site delays.
  • Noise reduction and fire resistance
  • In most cases, shuttering is not necessary. For instance, it is possible to run underfloor heating through hollows.
  • Block and beam floors eliminate the bounce associated with timber floors
  • Floors made of block and beam suffer minimal shrinkage, and they do not creak as they are used.
  • Using this method of floor construction, noisy homes are lessened. This is especially important in urban areas. Homeowners are concerned about noise within their homes. Block and beam floor construction has been used for many years in the UK in the construction of flats, and is now widely used in general housing to provide a quieter home living environment.
  • Can be laid in any weather
  • Reduces the load to the foundation
  • Good fire-resisting properties
  • Suitable to host underfloor heating systems.

Disadvantages Of Beam And Block Flooring

  • A more expensive option
  • Requires machinery to lift heavy beams into place
  • Unsuitable for irregular shapes that have many specialized units are not suitable because the method relies on standardization as the key to efficiency.
  • Providing even, rigid connections may be challenging when the floor and supporting beam or wall are irregularly shaped or have many specialized units.

Frequently Asked Question About Block And Beam Flooring

Is block and beam cheaper than slab?

Despite the fact that laying a slab of concrete is generally very cheap, it takes time for it to be set up and for it to dry, so in recent years, the beam and block suspended floor has gained popularity. Even though this method is a bit more expensive, especially for relatively small jobs, it’s extremely convenient and fast.

How far can beam and block span?

155mm House Beams are able to span up to a 7 metre point, while 225mm Deep Beams can span up to an 8 metre point under normal residential loading.

What goes under a block and beam floor?

Under a beam and block floor at ground level, there should be no topsoil or vegetation. Concrete or sand are not required. Between the bottom of the floor beam and the ground, a minimum distance of 150mm (225mm for heavy clay soils) must be maintained.

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