Here's Everything Worth Knowing About Thin Joint Blockwork

The materials and techniques you use in a building project play a big part in the success of it.

Masonry remains the most popular construction system in the UK, and with modern techniques and materials available, it’s an attractive option in terms of structure for self-builders and renovators. Thin joint blockwork is one of the top options, providing a host of benefits, including speed and efficiency. Here’s what you need to know about thin joint blockwork and why you should consider it for your project.

What is Thin Joint Blockwork?

Thin joint blockwork, also known as thin joint masonry, is both a fast and accurate construction technique with a host of benefits to the industry. The system consists of using autoclaved aerated concrete blocks of close dimensional tolerance with 2mm-3mm mortar joints, providing a clean and high-quality build.

The thin layer mortar is both pre-mixed and cement-based, needing only water to be added to result in an easy-to-apply mortar. Because it sets quicker, constructions are provided with quick stability too, with the depth of mortar reduced from at least 10mm to 3mm or less. 

The Benefits of Thin Joint Blockwork

The technique is gaining more and more popularity on sites due to the various benefits it holds, including that of speed, efficiency and productivity. Here are some of its advantages that you can expect when using thin joint blockwork for building projects.

Reduced Waste On Site

Site wastage can be considerably reduced with the use of thin joint blockwork - the autoclaved aerated concrete blocks are both easily and accurately cut on site. Any mortar wastage you do have can be reduced by batch mixing small amounts of thin layer mortar. With construction waste a big problem in the industry, this could be the answer to minimising waste throughout the building process.

Faster Build Speed

A serrated scoop is one of the building supplies used to apply thin layer mortar to autoclaved aerated concrete blocks, enabling the mortar to be applied both quickly and precisely to the bed of joints and perpends. This faster build speed is particularly beneficial and valuable when completing long runs of walling on site. For construction workers, finding ways to streamline work processes is paramount to success and enables builders to complete jobs faster without compromising on quality.

While a three-bedroom semi-detached house, made from timber and SIPs, takes up to 10 days to create a watertight superstructure on-site, thin joint blockwork takes only between 5 to 7 days. It’s a faster process and enables firms to complete projects at a quicker pace while still delivering what the client needs, to a high standard. 

Increased Thermal Performance

When assessing U-values for walls, the levels of heat loss through mortar joints must be considered due to the building regulations referring to the effects of cold bridging. That’s why it’s so useful that the construction of thin joint blockwork reduces and minimises this effect.

The amount of mortar in any area of the wall is reduced by at least 70% compared with what general use mortar construction can achieve. The thin joint technology also helps to result in improved airtightness, developing the overall performance of heat loss within the wall. 

High Levels of Productivity

The autoclaved aerated block walls, when built with thin layer mortar, will typically be stable after 60 minutes, guaranteeing high levels of productivity. Whole walls will not only be built and constructed in less time, but other installations such as floors and roof timbers will be able to start sooner than before. The sooner external brickwork can be completed, the sooner internal work such as services installation and plastering can be scheduled and begun, and the more time for products such as construction adhesive to dry.

Final Thoughts

The materials and processes you use when carrying out building projects are essential, so they require plenty of thought and research. Thin joint blockwork provides a number of benefits for those in the building sector, from increased quality and productivity to greater thermal performance to adhere to building regulations.