This general-purpose building block is designed for internal and external masonry where ease of handling, thermal performance, and moderate load-bearing strength are required. Rated at 3.6N/mm² compressive strength, it weighs significantly less than a standard dense block, making it faster to lay and ideal for reducing structural dead loads.

Common applications include:

• Inner Leaves of Cavity Walls: Provides superior thermal insulation compared to dense aggregate blocks, helping homes meet energy efficiency standards.

• Internal Partition Walls: Ideal for load-bearing and non-load-bearing dividing walls above ground floor level.

• Infill Panels in Frame Construction: Used as lightweight walling panels within steel or concrete frame structures.

• Protected External Walls: Suitable for outer leaves of cavity walls when covered with render, protective cladding, or timber framing.

Available for collection from our Rugby branch or local delivery using our own fleet.

Sterling board will typically be delivered in one of our vans or pick-up trucks, unless ordered alongside larger goods. Delivery is kerbside and the final offloading position is always subject to safe access and the driver’s discretion.

Please tell us before delivery about:

• Narrow roads or restricted entrances
• Parked vehicles or limited turning space
• Overhead cables, trees or other obstructions
• Soft, sloping or unsuitable ground
• Any other access concerns

Enter your postcode on the product page to check your delivery area. We’ll confirm the delivery date after your order is placed.

How heavy is a 100mm solid lightweight block compared to a standard dense block?

A 3.6N lightweight block typically weighs 10.5kg to 12.5kg, compared to a dense aggregate block which weighs roughly 18kg to 20kg. This lighter weight significantly speeds up installation and reduces site manual handling fatigue.

What does the "3.6N" strength rating mean?

The "3.6N" rating indicates a compressive strength of 3.6 Newtons per square millimetre (N/mm²). While lower than a 7.3N dense block, 3.6N provides sufficient structural strength for standard single and two-story domestic inner leaves, partition walls, and framed infill panels.

Are lightweight blocks good thermal insulators?

Yes. Lightweight blocks incorporate air-entrained cellular concrete or lightweight aggregates (such as furnace bottom ash or expanded clay), giving them a significantly lower thermal conductivity (? value) than dense aggregate blocks. This helps lower U-values and improve energy efficiency in house builds.

Can 3.6N lightweight blocks be used below DPC (Damp Proof Course)?

Generally, no. Standard 3.6N lightweight aggregate or aerated blocks are not typically recommended for below-ground footings or trench foundations exposed to high soil moisture and freeze-thaw cycles. Use 7.3N dense aggregate blocks or specialized foundation blocks below DPC instead.

Can I plaster or render directly onto lightweight concrete blocks?

Yes. Their textured surface provides excellent keying for direct application of sand/cement renders, dot-and-dab plasterboard adhesive, or traditional multi-finish wall plasters. A suitable primer or suction control coat may be required depending on the block type.

What wall fixings should I use for heavy items on lightweight blockwork?

Because lightweight blocks are less dense than aggregate blocks, use specialized aerated/lightweight block wall plugs or heavy-duty chemical anchors when mounting heavy fixtures like kitchen cabinets, boilers, or TV brackets.