What is a Stalton floor?
A Stalton floor is a Dutch floor system made of precast, prestressed concrete beams with a fired clay base, fired clay infill blocks between them, and a concrete topping cast on site. Once the topping has hardened, beams, blocks and topping act together as one load-bearing floor. Stalton is a brand name; the principle is that of a clay beam-and-block floor, similar to the concrete or polystyrene beam-and-block floors widely used elsewhere.
Pros and cons
Advantages:
- No crane needed: the separate beams and blocks can be placed by hand or with light lifting gear. Useful in renovation and on sites with poor access.
- Relatively light compared with a solid concrete slab.
- Plaster bonds well to the clay underside.
- Once plastered, the floor has good fire resistance.
- The porous clay is less prone to surface condensation.
Disadvantages:
- Heavier than beam-and-block floors with polystyrene infill.
- As a ground floor over a void, insulation is needed underneath, which adds work and cost. It is therefore mainly suited as an upper floor.
Application
- Have it designed. Beam spacing, topping thickness and reinforcement depend on span and load. The supplier or structural engineer provides a layout plan.
- Prop as instructed. During casting the beams often need temporary propping. Only remove the props once the topping has gained sufficient strength.
- Wet the blocks. Dry clay draws water out of the topping concrete. Dampen them before casting.
- Mind the bearings. Place the beams with adequate bearing length on the walls and follow the edge details.
- Drilling and cutting. Do not cut openings in an existing floor without advice; cutting through a beam weakens the floor.
Common mistake: adding heavy partition walls afterwards without checking whether the floor can take that line load.
Related terms
- EPS block floor
- Composite floor
- Structural topping
- Stalton lintel
- Structural engineer
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