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Our range of concrete blocks are resilient and durable products most of which are perfectly suitable for use below damp proof course (DPC) and as foundation wall blocks. The following block types are suitable for use below damp proof course (DPC) in soil conditions up to DS-3 as defined in BRE Special Digest 1. Please refer to individual product datasheets for suitable specific ground and exposure categories
• Airtec Standard or Airtec Seven Wall Blocks or Foundation blocks
• Ultralite Concrete blocks of 7.3N/mm² compressive strength or above
• Insulite Concrete block of 7.3 N/mm² compressive strength or above
• Dense Concrete blocks of any strength
Block not recommended for use below damp proof course (DPC):
• Airtec Airtec XL 2.9N Wall blocks
• Ultralite or Insulite blocks of less than 7.3N/mm² compressive strength
The presence of mobile water regularly percolating through the blocks can lead to eventual deterioration of the blocks and must be avoided.
Current building practice is such that wherever masonry is used below ground level it is usually limited to the top 1-meter depth. At the same time, sulphate levels in the top 1 meter of UK soils are rarely more severe than class DS-1. It follows that the depth at which samples are taken to enable the sulphate soil classification to be determined should be indicative of the depth where the masonry is being used. BRE Special Digest 1 draws attention to this.
Research by the BRE and the Concrete Block Association has shown that surface carbonation of aggregate blocks enhances their sulphate resistance, the requirement being that blocks are surface carbonated for a minimum of 10 days. Such exposure to air and surface carbonation will always take place without any special provisions between the time of manufacture of the block and back-filling after construction.
Airtec XL and Airtec Standard blocks are suitable for soil conditions DS1 & DS2 as defined in BRE Special Digest 1 and condition MX3.2 as defined in BS EN 1996-2 : 2006.
Airtec Seven, Ultralite 7.3N, Insulite 7.3N and Dense blocks are suitable for soil conditions DS1, DS2 & DS3 as defined in BRE Special Digest 1 and condition MX3.2 as defined in BS EN 1996-2 : 2006.
At Thomas Armstrong (Concrete Blocks) Ltd we pride ourselves on our high level of customer service across the company. Our friendly staff will be more than happy to help answer any questions you have relating to sales and our products as well as any technical advice you have. Please contact our local office (see offices) near you today!