This article is a step-by-step overview of best practices for AAC block masonry, focusing on essential aspects such as foundation readiness, moisture control, proper block handling, mortar application, reinforcement, and compliance with construction standards. Designed for engineers, site supervisors, and construction professionals, it ensures every AAC block structure is built with strength, durability, and precision. These guidelines will help you prevent common issues like cracking and poor bonding, ensuring a higher-quality finish and longer service life.
Before commencing masonry, it is important to verify that the foundation has been properly laid. The slab or plinth must be level and free of dust, debris, oil, or any substance that would compromise the quality of the first layer of blocks and its finish.
You should also have applied a damp-proof course to the surface to protect the structure from moisture rising through capillarity. In cases of an uneven surface, you should level it off with a rich mortar mix before commencing block work.
Because AAC blocks are hollow, they tend to absorb moisture very rapidly. If not stored correctly, AAC Blocks would become brittle and compromise the quality of the masonry. Therefore, you will need to place the blocks on a level and dry surface, and preferably off the ground, using wooden planks or pallets. Cover the blocks prior to rain, from ground dampness, and dust with a waterproof sheet or a plastic tarpaulin.
Don't make the stack too high to avoid falls, and also do not chip the corners of the blocks because you were gentle with them.
AAC blocks require a specific type of mortar. We recommend a thin-bed adhesive or a ready-mix mortar specifically manufactured for AAC materials for the best adhesion and finish. This will provide a uniform bond, faster application, and reduced wastage.
Mortar should be mixed as per the manufacturer’s instructions, following the correct water-to-powder ratio.
AAC blocks do not need to be soaked as traditional bricks; however, lightly sprinkling or wetting the surfaces will assist in reducing suction, in turn ensuring that the mortar retains moisture to ensure correct curing. Over-wetting is not recommended, as it weakens bonds and increases the possibility of cracking.
Though AAC blocks are structurally dense due to their compressive strength, they require structural reinforcement for heavy load-bearing applications. Reinforced cement concrete (RCC) stiffnesses will be provided at specified lengths, generally perpendicular to the block lengths at 3-meter intervals and in terms of height, every 1.2 meters. If vertical and/or horizontal reinforcement bars are required, they may be included as required based on thickness and the design.
All openings, such as doors and windows, require barriers, which are the lintels and sill bands to spread loads evenly and prevent cracking.
It is recommended that AAC blocks not be used below ground level or in wet areas of prolonged exposure; all masonry in wet areas, such as foundations, water tanks, drainage channels, etc. Generally, because AAC blocks tend to absorb a lot of water, they could spall the materials.
Therefore, it is best to keep AAC blocks above the plinth level and protect them by applying plaster or a water-resistant coating.
Before walls are built, it is critical to plan all electrical and plumbing chases because chasing randomly or too deeply after blocks have been laid can seriously diminish the integrity of the wall. When chasing a wall, the chase should not exceed one-third of the wall's thickness vertically, and it should not exceed one-sixth horizontally. Any chasing should only be done using appropriate tools to lessen damage.
One of the more troublesome issues with AAC masonry is the cracking of walls at the junction of RCC elements (columns, beams, etc.) and AAC wall may occur. It is a good practice to apply, before plastering, a fiberglass or chicken mesh at the junction because the mesh creates a barrier so that any differential movements will be absorbed by the mesh, thereby greatly limiting surface cracking.
AAC block masonry requires less curing than traditional brick, and only light curing for about 5 to 7 days is needed to achieve a proper set of the mortar. Do not over-cure and dampen, as doing so can cause efflorescence or a weak bond of the blocks.
With regard to the use of AAC Blocks, ensure the following aspects during construction of buildings: blocks must be uniform and without cracks; blocks must be fully cured; we should not use broken or chipped blocks, as blocks that are broken or chipped will weaken the total masonry performance.
Conclusion
There are proper precautions to take before completing the laying of AAC block masonry if one wants to achieve quality, durable, and safe structures. A consideration must be given to the handling and storage of the block, selecting an appropriate mortar, and consideration to structural reinforcements, all of which contribute to the sustainable delivery of the building, ultimately leading to the/presentation to the client the following benefits to AAC blocks. The knowledge of these topics will ensure that all the benefits of AAC blocks are utilized properly on every project. Reach out to us for More Info.
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