Chris Hirst discusses the benefits of Orlitech mesh, a modern alternative to traditional steel mesh for use within ground-bearing slabs.
The UK housebuilding industry remains rooted in tradition but with pressures mounting for faster, more efficient, greener and cost effective homes, we’re exploring and considering new products and innovations that can support our wider objective.
Orlimex is global company operating in 12 countries. The launch of the firm’s Orlitech composite products has been embraced throughout Europe and especially so in North America. The material represents a replacement for reinforcement steel mesh for use in concrete builds and, thanks to its many benefits, is a great proposition for the small to medium size housebuilder and developer.
A key attribute is the material weight, which is seven times lighter and 2.5 times stronger than traditional steel. Its low weight makes it especially easy to handle and is suitable for all kinds of flooring including underfloor heating – this mesh does not react to temperature fluctuation. Due to lower weight and volume, transportation costs are reduced, whilst the mesh can be easily installed by one person, significantly reducing assembly time. Mesh for screeds, ground bearing concrete slabs and structural toppings is supplied on a roll (22.5M2 -36M2) which lies completely flat once off the roll, reducing installation time, one person can lay the mesh some three times faster than traditional steel mesh. Health and safety risks are reduced due to the lightweight 0.35Kg/M2 and ease of cutting. All these characteristics contribute to great financial savings.”
It’s also a relatively simple treatment and application. Each roll is between 80cm and 1.2M wide and up to 30m long. Due to compact packaging and easy cutting, users are able to save a considerable amount of time when laying and, due to its minimal overlap, it is convenient for numerous rooms.
The mesh is resistant to corrosion and UV radiation. It doesn’t change its mechanical features, and won’t cause any degradation of concrete. Moreover, due to the high alkali resistance and anti-corrosion properties, it prolongs concrete lifetime by up to three times, which also means that is suitable for use in chemically aggressive areas. The mesh does not conduct electricity and is non-magnetic, it does not absorb static energy and is redundant to radio waves.”
For control of shrinkage cracking Orlitech mesh reinforcement 2.2mm x 100mm x 100mm can be used as a direct replacement for D49 or A142mesh, used in exactly the same way but laps of only 100mm are recommended. The increased tensile strength means that smaller diameters of wire can be used compared with steel, dramatically reducing installation time. Many companies begin using Orlitech mesh for day joints but once the benefits are recognised, including a lower overall cost, the decision to use Orlitech mesh as standard is becoming more common.
Steel mesh is commonly used in ground-bearing slabs where control of concrete shrinkage is important, generally we can offer a 3mm 100×100 mesh to control cracking in these situations. An engineer is still required to design the slab and we can give help and guidance and even provide calculations to prove the suitability of Orlitech mesh. No more need to be carrying large sheets of steel simply roll out the mesh using standard chairs or rails and pour your concrete days earlier.
The main constituent of the product is basalt rock, one of the most common in the world. This is spun into fibres and mixed with resins to form bars – the same technology as carbon fibre. The production process uses very small amounts of our natural resources and, as such, has a carbon footprint some 40 times less than steel during production. Carbon off-setting is recognised as a poor solution to our current ecological crisis – the best way forward is to reduce our carbon footprint at source.
Nor does this solution have welded connections – each BFRP wire is continuous and jointed with a patented connection nodule. The mesh lies completely flat once taken off the roll and can be easily cut with a pair of pliers.
Both steel and Orlitech mesh reinforcement are inactive until such a time that the concrete shrinks. Once the concrete shrinks the reinforcement becomes active and prevents / restricts cracking and prevents the screed from curling. The reinforcement should be supported and tied together to reduce movement during pouring of the screed to maintain correct placement within the screed. For structural use larger diameter mesh is provided – due to the increased tensile strength of BFRP a smaller diameter mesh can be used as opposed to that of steel. For load bearing slabs we recommend that we provide you with a structural calculation to ensure the best alternative is used.
Structural reinforcement mesh from Orlimex consists of 6mm – 12mm mesh and can be used to increase the load bearing capacity of the slab. In this case the larger diameter mesh would be used for the bottom layer and the 3mm mesh for crack control for the top layer.”