What is a beam and block floor?

A beam and block floor is a suspended flooring system consisting of pre-stressed concrete T-beams and infill blocks (usually standard 440x215x100mm concrete blocks). It is a fast, reliable, and fire-resistant method for constructing ground and upper floors in the UK.

What spacing should I use for the beams?

Standard spacing is 440mm centres, which fits a standard block length. If the floor needs to support higher loads, beams can be 'doubled up' or placed at tighter centres. 'Wide' spacing of 520mm is sometimes used where blocks are laid on their side.

Do I need a DPC under the beams?

Yes. Pre-stressed concrete beams must be bedded onto a Damp Proof Course (DPC) at their bearing points on the internal skin of the masonry to prevent rising damp from entering the floor structure.

How do I 'lock' the floor together?

Once the beams and blocks are laid, the entire floor must be 'brushed' with a sand and cement slurry (typically a 1:4 mix). This fills the gaps between the blocks and the beams, locking them together and creating a rigid, squeak-free floor surface.

What is a beam and block floor?

A beam and block floor is a suspended flooring system consisting of pre-stressed concrete T-beams and infill blocks (usually standard 440x215x100mm concrete blocks). It is a fast, reliable, and fire-resistant method for constructing ground and upper floors in the UK.

What spacing should I use for the beams?

Standard spacing is 440mm centres, which fits a standard block length. If the floor needs to support higher loads, beams can be 'doubled up' or placed at tighter centres. 'Wide' spacing of 520mm is sometimes used where blocks are laid on their side.

Do I need a DPC under the beams?

Yes. Pre-stressed concrete beams must be bedded onto a Damp Proof Course (DPC) at their bearing points on the internal skin of the masonry to prevent rising damp from entering the floor structure.

How do I 'lock' the floor together?

Once the beams and blocks are laid, the entire floor must be 'brushed' with a sand and cement slurry (typically a 1:4 mix). This fills the gaps between the blocks and the beams, locking them together and creating a rigid, squeak-free floor surface.

Beam & Block Calculator

Suspended floor material takeoff for new builds.

Span Width (m)

Span Length (m)

Beam Spacing (Centres)

Material Takeoff

Handling Tip: Concrete T-beams are extremely heavy and should never be dropped. Use a **Hiab** (crane truck) to position them close to the slab. When walking on the beams before the blocks are in, use scaffold boards to spread your weight.

Suspended Solutions: The Beam & Block Advantage

Fast & Efficient

Beam and block flooring has become the standard for UK ground floors because it can be installed in almost any weather condition, requires no formwork, and provides an immediate working platform for the rest of the build.

Our **beam and block calculator** provides a quick estimate for the primary components needed, including T-beams, infill blocks, and perimeter slip bricks.

Standard Configuration

Block Size440 x 215 x 100mm

Beam Spacing440mm Centres

Coverage~9.5 Blocks per m²

Bearings & Spans

Pre-stressed concrete beams must have a minimum bearing of **100mm** on each supporting wall. For clear spans over 4 metres, the beams become significantly heavier and deeper (typically 150mm or 225mm deep).

Always ensure that the sub-floor void is correctly ventilated using **telescopic vent snorkels** and air bricks to prevent the buildup of radon gas or moisture-induced rot in any adjacent timber elements.

Slip Bricks

Slip bricks are used to seal the perimeter of the floor where the beams meet the walls. They prevent the infill blocks from moving and provide a level surface for the next course of masonry or the DPC.

Thermal Efficiency

For enhanced energy ratings, you can use **thermal infill blocks** (made of high-density EPS) instead of concrete blocks. These provide a much higher U-value and significantly reduce heat loss through the floor.

Pro Tip: Cutting Beams

Never attempt to cut pre-stressed concrete beams with a standard hand saw or small grinder. They contain high-tension steel wires that can snap violently. Always use a high-powered **petrol saw** with a diamond blade and wear full PPE.

Beam & Block Flooring FAQ

Structural Disclaimer

This calculator is for material estimation only. The structural design of a suspended floor (including beam section and doubling-up requirements) must be performed by a qualified structural engineer or provided by the beam manufacturer's technical office.