Take a concrete look at new standards with Aggregate

16 Nov 2017

Aggregate Industries is advising housebuilders to look closer at the technical considerations before installing block and beam flooring, with the 1st January 2018 deadline for the National House Building Council’s (NHBC) Technical Extra 20 standard drawing closer.

The new standard states that the use of micro fibres, when installing a block and beam type system, instead of steel mesh reinforcement, is no longer acceptable to the NHBC.

Instead, approved macro structural fibres or steel fibres are deemed are now acceptable for use as reinforcement. According to the guidance, structural toppings on insulating block and beam systems requiring approval by the NHBC must use one of the following reinforcement options; macro ‘structural’ synthetic fibres, steel fibres or steel mesh reinforcement.

Managing Director for Asphalt and Readymix at Aggregate Industries, Chris Hudson, commented: “There is no doubt that the methods used to construct new floors have come on in leaps and bounds in the last decade.

“However block and beam floors still remain the most popular solution for housebuilders when building a ground floor and so it’s important that they are in-tune with the latest guidelines.

“In order to stay ahead of the game and iron out teething problems housebuilders should already be well underway in adopting these changes.

“However, there are a number of considerations that must be taken into account and housebuilders must be aware of the implications, which is where starting conversations early doors with suppliers will come in handy.”

Chris’ top tips for housebuilders when selecting concrete for block and beam flooring include speaking with your materials supplier for advice, as they can help you understand the product limitations and unique benefits, and can create a bespoke product where required.

He also says to select the appropriate types of pre-cast concrete beam and block to suit the structural and thermal requirements of the suspended floor construction and ensure that the beam type is compatible with the block type specified, in accordance with BS EN 15037.

The design of the concrete topping must be structurally suitable for use with the beam and block system specified, whilst being in line with the systems BBA approval and making sure you are aware of NHBC restrictions on use of possible alternatives to welded steel mesh reinforcement for structural concrete toppings are further recommendations from Chris.

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