Celcon Blocks
(6 Products)Celcon Blocks, manufactured by H+H, deliver reliable thermal insulation, airtightness, and durability in a single solution. Confidently labelled the ‘Ultimate Masonry Product’ by the manufacturer, they are ideal for constructing solid walls, partition walls, and both the inner and outer leaves of cavity wall systems.
Orders large enough to require a pallet will require a £20 refundable pallet charge to be paid per pallet. Our customer service team will reach out to you if this applies to your order.
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What Are Celcon Blocks?
Celcon blocks are aircrete masonry units made from a carefully balanced mix of cement, lime, sand, water, and pulverised fuel ash (PFA).
During manufacturing, a small amount of aluminium powder is added, reacting with the lime to form hydrogen bubbles. This creates a cellular structure that results in a strong, lightweight, and highly insulative building material.
Widely recognised for their versatility, Celcon blocks can be used across a range of structural and non-structural applications. These include internal and external walls (whether solid or cavity) along with floor systems and partitions. Their use helps to simplify site logistics and reduce material variation on site.
Celcon blocks deliver excellent thermal and acoustic performance, as well as reliable load-bearing capacity.
We offer:
- 100mm H+H Standard Grade (3.6N): A reliable option for everyday walling jobs.
- 100mm H+H High Strength Grade (7.3N): Best for structural work where extra strength is needed.
Applications
- Internal or external walls
- Solid wall construction
- Both leaves of cavity walls
- Partitioning and party wall systems
- Flats and house builds
- Basements (as long as suitable waterproofing is used)
- Beam and block flooring
- Fire-rated walls
Regulations & Compliance
Celcon Blocks meet the relevant parts of the Building Regulations, including:
- Part L - Energy efficiency
- Part E - Sound Insulation
- Part A - Structural strength
- Part B - Fire Safety
They also support the performance goals of the Future Homes Standard (2025), particularly where thermal efficiency and airtightness are concerned.
Fixings and Finishes
You can’t use standard wall plugs for fixings - use aircrete-specific fixings (like frame fixings or resin anchors).
Blocks can be finished with:
- Plaster or drywall internally
- Render, cladding, or brick slips externally
- Dot-and-dab systems work well with Celcon too
Block Strength and Specification
Choose the correct compressive strength for the job:
- 3.6N - Suitable for most domestic walls
- 7.3N / 8.7N - Needed for taller walls, concentrated loads, or multi-storey buildings
Always check the structural engineer’s design if in doubt.
Frequently Asked Celcon Blocks Questions
Are Celcon Blocks Fireproof?
Celcon Blocks are classed as non-combustible (Euroclass A1). When used in a suitable wall build-up, they can provide up to 4 hours of fire resistance - depending on the thickness and design.
Can Celcon Blocks Plastered and Rendered?
Yes, they can. Internally, they take plaster or dot-and-dab finishes with no issue. For external use, render can be applied, but correct preparation is essential to prevent moisture problems.
How Do Celcon Blocks Compare To Traditional Concrete Blocks?
Celcon Blocks are lighter, easier to handle, and offer far better thermal performance. Dense concrete blocks are generally stronger in compressive strength. Celcon is more efficient for insulation and speed of installation.
Are Celcon Blocks Waterproof?
No, they aren’t. Celcon is a porous material, so it needs protection in exposed areas. This can be done with external render, cavity wall construction, or damp-proofing where required.
What Are Mortar Perpends/Perps?
The term "perpends" comes from old English and refers to the head or vertical mortar joints in bricks. Unlike horizontal bed joints, which are easier to fill, head joints require sufficient butting to prevent gaps in the wall system.
