Our castle mesh spacers are expertly crafted from high-strength fibrous concrete, delivering outstanding durability with a minimum concrete strength of 50N/mm². Designed to meet the rigorous standards of BS7973-1:2001, these spacers ensure precise rebar placement and optimal concrete cover, which are crucial for concrete projects' structural integrity and longevity.
Their high compressive strength, precise dimensional tolerances, and resistance to temperature fluctuations ensure long-lasting performance. With superior physical and chemical resistance, they bond seamlessly with in-situ concrete, preventing hairline cracks and are suitable for waterproof concrete. They are also fire-resistant to EN13501-1:2002 Class 1A standards, making them a reliable choice for site and precast concrete applications.
Product specifications
- Pieces Per Bag: 100
- Cover Size: 40-50mm
- Compression Strength: ≥ 50N/mm² (BS7973 PT1-2 compliant)
- Materials: CEM I 52.5 N, Concrete Sand, Calcium Carbonate, PFA
- Water Penetration: ≤ 3mm
- Height Accuracy: ±1mm for 20-75mm cover
- Height Accuracy: ±2mm for 80-100mm cover
- Reinforcement: Polypropylene Fibres, Polyester threads
- Slump: S1 (0-3cm)
How Many Concrete Castle Spacers Do I Need?
Concrete castle spacers are high-strength point supports used for heavier duty, external and structural concrete work. They comply with BS 7973-1:2001 and are supplied 100 per bag. Here is how to calculate how many bags to order:
Quick guide per mesh sheet
| Slab Type |
Recommended per 3.6 x 2.0 m Mesh Sheet |
| Standard domestic or light commercial slab |
4-6 castle spacers per sheet |
| Heavy duty, external or industrial slab |
6-8 castle spacers per sheet |
| Structural element, engineer specified |
Follow engineer's drawing - use this as minimum |
Calculate by slab area
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Standard slabs: 0.5 spacers per m² (minimum)
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Heavy duty / external slabs: 0.75-1 spacer per m²
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Structural / engineer specified: follow drawings; use above as minimum
Example: A 12 m x 8 m commercial slab (96 m²) at 0.75 spacers per m² = 72 castle spacers. Round up to 1 bag (100 pieces). Add 10-15% for waste = 83 minimum, so 1 bag is fine for this example.
Placement tips
- Place castle spacers in a staggered grid, not in straight lines
- Keep spacing between supports to no more than 800 mm for standard slabs
- Reduce to 600 mm spacing for heavy duty, industrial or external slabs
- Add extra spacers at edges, laps and around openings
- Ensure the spacer base sits firmly on a level surface before placing mesh
- These spacers are non-combustible and bond with the in-situ concrete - ideal for fire-rated and external applications
→ See our full spacer calculator guide for worked examples and slab area calculations across all spacer types.
