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EXTERIORS


Ultra high pressure jetting a concrete removal ‘gamechanger’


A


specialist team from drainage and wastewater specialist Lanes Group plc has prevented the need to partially


demolish three houses by using a water jet to remove concrete from a sewer pipe. The ultra-high pressure (UHP) jetting system, which powers the water jet to over the speed of sound, was deployed after the foundation concrete in the pipe proved too tough for conventional robotic cutting. The only practical alternative would have


been to excavate and replace the pipe, buried three metres beneath extensions built behind the row of nine terraces homes in Ilford, north east London. That would have involved the extensions for


three of the homes being all but demolished, then reinstated, with the occupants placed in temporary accommodation while the work was done. Lanes carried out the UHP jetting project on behalf of Thames Water and has now used the technique to complete other challenging concrete removal projects for the water company.


Lanes Operations Manager Calvin May said:


“This was one of the toughest concrete removal projects we’ve ever tackled, and involved contamination of a 150mm-diameter sewer. “We believe the concrete may have been linked to a nearby building project. Foundation


HBD12_Lanes Group_Groundworks - Drainage_HPAdv.indd 1


concrete is particularly hard and, in this case, had time to set solid, completely fi lling the pipe for 11 metres. “We didn’t make very fast headway


with a robotic cutter, which works by grinding down the concrete, so we needed a diff erent approach.


“UHP jetting turned out to be a gamechanger.


It was over 20 times as fast as using robotic cutting and prevented the need for an alternative solution that would’ve been much more costly and disruptive.” It meant the concrete could be removed in 15


shifts, equivalent to three weeks’ work. Lanes, Thames Water’s wastewater network


services maintenance partner, developed a business case for using UHP jetting to ensure it would work and be cost-eff ective. This led to the initial hiring of a UHP jetting


system to ensure the concrete removal process was eff ective - not least because a tanker was having to visit the site every day to remove sewage building up behind the blockage. Lanes selected a Falch UHP pump combined with an IMS Robotics jetting system, capable of delivering a water jet at 2,500 bar (over 36,000 pounds per square inch). Six Lanes wastewater operatives underwent


Water Jetting Association hydrodemolition training and equipment supplier instruction to give them the knowledge and skills needed to


operate the system. The UHP jetting system has a jetting nozzle on the end of a hose encased in a fl exible steel coil sheath. Once guided into the pipe, a packer is infl ated with compressed air to hold the nozzle fi rmly in place inside the pipe. A mini camera and powerful LED lights


allowed the Lanes operative to then view the jetting operation, while controlling the nozzle with a joystick to direct it most eff ectively at the concrete. The concrete was removed in one-metre


sections, with the exposed pipe strengthened by installing a cured in place pipe (CIPP) point liner made from fi berglass matting, impregnated with resin. Once the resin had cured, the liner created a


durable new concrete-free pipe within a pipe, with a design life of at least 50 years.


0800 526 488 www.lanesfordrains.co.uk 16/11/2023 11:53


Warning: Are your louvres non-compliant?


Renson UK National Sales Manager Martin Daniels explains how honest testing isn’t always as transparent as it should be...


W


hen specifying louvres for architectural projects,


it’s imperative that the products


selected are of the highest quality. At Renson UK, we’ve spent the past 50 years designing, developing and manufacturing high- performance ventilation products, supplying fully tested,


high-quality louvres and


mechanical ventilation products for every application. It’s during this time that we’ve come across many non-compliant louvres in the market – and it all comes down to testing. The industry standard for weather testing of louvres in the UK was developed by the Building Services Research and Information Association (BSRIA) in collaboration with the Heating, Ventilation and Air Conditioning Manufacturers Association (HEVAC), and was adopted in 2001 as British and European Standard: BS EN 13030:2001. Since then, BS EN 13030:2001 has tested louvres in three key performance


areas – water penetration, or the ability to prevent rain penetrating the louvre; pressure drop, or how freely the louvre allows air to pass through; and overall performance, a combined measure of


both. The tests


themselves simulate the real-life operating conditions that a louvre will undergo when installed, enabling clients to compare one manufacturer’s performance against another. During the water penetration test, the louvre is subjected to a simulated rainfall rate of 75 l/h and a wind speed of 13 m/s (30 mph). The rejected water is collected in the weather section, and water in the collection duct is measured to calculate the percentage of water penetrated through the louvre. In


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addition to the simulated wind at 13m/s, air is drawn through the louvre to simulate inlet ventilation rates. The problem is, the BS EN 13030:2001 test does not measure or give consideration to the way the water is collected, and it’s therefore easy to get away with placing an abnormally large collection plate behind the louvre simply for the sake of the test. Therefore when comparing different


louvres, it is important to obtain a full copy of the test report – a full report will show if any large collection trays were incorporated. Because of this loophole in the BS EN 13030:2001 test, we’ve seen a countless number of louvres being approved and highly rated, but that end up being non- compliant, and at Renson, the last thing we want to do is let our customers down with an inferior product. We therefore provide all our customers with full test reports for complete transparency – additionally, all our test reports are freely and easily downloadable from our website.


www.renson.eu/en-gb/for-professionals/contact 11/09/2023 12:20


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