What Is AAC Block? Complete Guide for Malaysia (2026)

Key Takeaways

• AAC blocks are lightweight: They weigh 3–5× less than conventional concrete blocks, making them easier to handle on site.
• High water absorption is the main weakness: AAC blocks can absorb up to 20% water — proper waterproofing is essential for external walls in Malaysia.
• SIRIM MS 2514 is the Malaysian standard: Specify AAC blocks under this standard for compliant construction.
• ALC panels install 7.5× faster: If timeline and labour cost matter, modern ALC panels like vPanel offer a significant upgrade over AAC blocks.
• Autoclaving makes AAC blocks energy-intensive: The manufacturing process requires high-pressure steam curing, which drives up production cost and carbon footprint.

Introduction

If you’re specifying wall materials for a project in Malaysia — whether residential, commercial, or industrial — AAC blocks are likely on your shortlist.

They’re widely available, lightweight, and meet Malaysia’s fire and thermal requirements. But as construction demands evolve, more contractors and developers are asking: is there something better?

This guide gives you the full picture — what AAC blocks are, how they’re made, their real technical specs, and what alternatives exist for Malaysian projects in 2026.

What Is an AAC Block?

An AAC (Autoclaved Aerated Concrete) block is a lightweight building material made from cement, sand or fly ash, lime, water, and aluminium powder. The aluminium powder reacts with the alkaline mixture to create millions of tiny air bubbles, giving the block its characteristic lightweight, cellular structure. AAC blocks are then steam-cured in a pressurised autoclave to achieve their final strength.

AAC stands for Autoclaved Aerated Concrete. It is one of the most widely used lightweight wall materials in Malaysia, replacing conventional clay bricks in many residential and commercial projects.

The air-bubble structure inside the block gives it three key properties:

• Lightweight — approximately 3–5× lighter than standard concrete
• Thermally insulating — the trapped air reduces heat transfer
• Fire resistant — AAC blocks achieve 2–6 hour fire ratings depending on thickness

Common AAC block applications in Malaysia include residential partition walls, commercial office interiors, industrial factory partitions, and any non-load-bearing wall application.

How Are AAC Blocks Made in Malaysia?

AAC blocks are produced through a 6-step process: raw material mixing, pouring into moulds, rising through hydrogen gas reaction, wire cutting, autoclaving (180–200°C for 8–12 hours), and quality testing. The autoclaving stage — high-pressure steam curing — is what gives AAC its strength and dimensional stability, but it is also the most energy-intensive and expensive step.

Here is the manufacturing sequence in detail:

1. Raw material mixing — Sand or fly ash, cement, lime, water, and aluminium powder are combined into a slurry.
2. Pouring and rising — The slurry is poured into large moulds. Aluminium reacts with lime to release hydrogen gas, causing the mixture to rise (similar to bread dough), creating the cellular structure.
3. Pre-curing — The poured mass partially hardens at room temperature for 2–4 hours.
4. Wire cutting — The semi-hardened block is precision-cut to required dimensions using steel wires.
5. Autoclaving — Blocks enter a pressurised steam chamber at 180–200°C for 8–12 hours. This step gives AAC its final compressive strength and dimensional accuracy.
6. Quality testing — Blocks are tested for compressive strength, density, and dimensional tolerance before leaving the factory.

The autoclaving step is expensive. It requires significant energy (electricity and steam) and large capital investment. This is one reason why non-autoclaved alternatives — such as vPanel ALC panels — can often be priced competitively while delivering similar or better performance.

What Are the Technical Specifications of AAC Blocks?

In Malaysia, AAC blocks are specified under SIRIM MS 2514. Density ranges from 400–800 kg/m³, compressive strength from 2.5–7.5 N/mm², and thermal conductivity from 0.10–0.24 W/mK. Standard block dimensions are 600mm × 200mm, with thicknesses of 75mm to 200mm. Fire resistance ranges from 2–6 hours depending on density class.

The table below shows the three density classes used in Malaysian specifications:

Specification	Class A (Low Density)	Class B (Medium)	Class C (High Density)
Dry Density	400–500 kg/m³	501–700 kg/m³	701–800 kg/m³
Compressive Strength	≥ 2.5 N/mm²	≥ 3.5 N/mm²	≥ 5.0 N/mm²
Thermal Conductivity	~0.10 W/mK	~0.14 W/mK	~0.20 W/mK
Fire Resistance	2–4 hours	2–4 hours	3–6 hours
Water Absorption	Up to 20%	Up to 18%	Up to 15%
Best Use	Interior partitions	Commercial / light industrial	External walls / structural
Common in Malaysia?	Most common	Common	Less common

Class A blocks are the most widely specified in residential projects. Class B is common for commercial office partitions. Class C is selected for external walls requiring higher strength and lower moisture absorption.

How Do AAC Blocks Perform in Malaysia’s Tropical Climate?

AAC blocks perform reasonably well in Malaysia’s heat, providing better thermal insulation than red bricks. However, their high water absorption rate (up to 20%) is a serious concern in Malaysia’s year-round humid, high-rainfall environment. External AAC block walls must be properly waterproofed and rendered to prevent moisture ingress, efflorescence, and long-term wall damage.

Malaysia’s climate creates specific challenges for AAC blocks:

• High humidity: AAC’s open-cell air structure absorbs moisture from the atmosphere over time, leading to damp walls if not properly sealed.
• Frequent rain: External AAC walls without render coatings are vulnerable to water penetration during heavy monsoon rain.
• Heat: AAC performs better than red brick in heat insulation, but its thermal conductivity of 0.10–0.24 W/mK is still higher than next-generation ALC panels.

Best practice for external AAC block walls in Malaysia: apply a waterproofing render coat or external plaster before painting. For wet areas — bathrooms, food processing plants, or building facades — consider materials with lower water absorption.

By comparison, Vodapruf vPanel ALC panels use a closed-cell structure infused with LIGHTHERM aggregate, resulting in significantly lower water absorption and better thermal performance in Malaysia’s climate.

What Is the Price of AAC Blocks in Malaysia?

AAC block prices in Malaysia typically range from RM 1.50 to RM 3.50 per block, depending on thickness, density class, and supplier. Thicker (150mm+) and higher-density blocks cost more. Bulk orders above 5,000 blocks usually attract negotiated pricing. Always factor in delivery costs — freight to sites in Sabah, Sarawak, or remote Peninsular areas adds significantly to the total price.

Thickness	Typical Price (RM/block)	Common Use
75mm	RM 1.50 – 2.00	Light partitions, non-structural
100mm	RM 1.80 – 2.50	Standard interior partitions
125mm	RM 2.20 – 3.00	Office walls, semi-external
150mm	RM 2.80 – 3.50	External walls, acoustic partitions
200mm	RM 3.20 – 4.00+	High fire-rated / structural walls

Note: Prices are estimates as of 2026. Actual pricing varies by supplier, volume, and delivery location. Request quotes from at least 2–3 suppliers before finalising your bill of quantities.

What Are the Advantages and Disadvantages of AAC Blocks?

AAC blocks offer proven lightweight construction with good thermal and fire performance. Their main disadvantages are high water absorption, slow installation speed compared to large-format panels, and higher susceptibility to joint cracking over time. For large-scale projects with tight timelines, modern ALC panels are increasingly preferred.

Factor	AAC Block	vPanel ALC Panel
Weight	400–800 kg/m³	~550 kg/m³ (similar, but larger format)
Thermal Conductivity	0.10–0.24 W/mK	0.125 W/mK (superior per unit area)
Fire Rating	2–6 hours	Up to 4 hours
Water Absorption	Up to 20%	Very low (closed-cell structure)
Installation Speed	Baseline	7.5× faster per m²
Labour Cost	Higher (more blocks, more joints)	70% labour savings on large sites
BCA Buildability Score	Lower	LSI 0.85 (meets SG BCA requirements)
Green Certification	Varies by supplier	Green Label certified
Plastering Required?	Yes (typically)	No — direct skim coat

Is There a Better Alternative to AAC Blocks in Malaysia?

For projects over 1,500 m² of wall area — or where construction timelines are critical — ALC panels are a proven upgrade to AAC blocks. Vodapruf vPanel ALC panels install 7.5× faster, require no plastering, and have lower water absorption. They carry the Singapore Green Label certification and are used in projects including the Apple Data Centre and Singapore General Hospital.

AAC blocks remain a solid choice for small residential projects with flexible timelines and limited wall areas. But the industry is shifting.

Here’s when to choose each:

Choose AAC Blocks when…	Choose vPanel ALC Panel when…
Project wall area is under 1,000 m²	Project wall area is over 1,500 m²
Timeline is flexible	Delay penalties apply or timeline is tight
Budget priority is material cost only	Total project cost (materials + labour) is the target
Site has good block storage space	Site access is limited (Short Panel fits in standard lifts)
Plastering crew is available	You want to skip the plastering step entirely

Vodapruf manufactures vPanel from our 5-acre factory in Kulai, Johor, and supplies projects across Malaysia and Singapore. We offer free project consultations to help you decide which wall system is right for your specific project.

Conclusion

AAC blocks have served Malaysia’s construction industry well for decades. They’re lightweight, fire-resistant, and widely available. But in 2026, the industry has better options for speed, thermal performance, and sustainability.

If you’re evaluating wall materials for your next project — whether residential, commercial, or industrial — it’s worth comparing the full cost picture: materials, labour, timeline, and finishing.

Planning Your Next Project in Malaysia or Singapore?

Vodapruf has supplied wall panel and lightweight aggregate solutions to 700+ projects in Singapore and across Malaysia — including the Apple Data Centre, Singapore General Hospital, and industrial sites in Johor and Kuala Lumpur. Our team can advise on the right wall system for your project scope and timeline.

Whether you’re comparing AAC blocks and ALC panels, or ready to request a quote — we’re happy to have a practical conversation with no commitment required.

📞  Malaysia: +60 16 217 7155
📞  Singapore: +65 9796 5910
🌐  vodapruf.com

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