BASEMENT DRAINAGE –THE NEW GENERATION

from FC&A February 2023

BUILD FOCUS:

CAVITY WALL OPENINGS: NHBC – BS 6515 AND BS 8215

The NHBC announced within its Technical Guidance 6.1/38 that Polythene Damp Proof Course made to BS 6515:1984 will not be accepted on all plots starting, or at DPC level, on that date. The NHBC announcement aligns with the usage/ restrictions stated within the long-established British Standard, which qualifies such DPC as not suitable where there is a downward movement of water. The announcement includes a reference to the code of practice – BS 8215:1991, which provides installation guidance for damp course in masonry construction. Many will welcome this move, as the downside of any roll DPC is the necessity to cut and form on site, with the accompanying variances, errors and inconsistencies that can occur. e et the new generation – with a unique design, impressive storage capacity, Finite Element Analysis (FEA) and exceptional durability. he redesigned V3, V4, V6 and V3 foul chambers deliver the core performance expected from the Delta brand, not forgetting the all-important cost savings – less excavation costs, less labour costs and less requirement for concrete/steel (when housed). also self-supporting, which means they hold to profile and do not require building into the inner skin (unless you request otherwise). So, not seeking out a bedding joint at an appropriate height to hold up the protection. Full cavity width arrestment is provided by the preformed tray that is biased to take up the cavity width encountered. Both skins remain independent of each other. Adverse thermal bridging is not introduced.

We strive to be known for the quality of our products, using our industry knowledge base as a starting block. Delta’s vision and values balance evaluating our products with market demand to ensure both align,” explains Delta’s Founder, Christopher Burbridge.

On 1st January 2023, the use of conventional roll DPC to provide protection against wet ingress over window and door openings in cavity walls changed.

T he alternative way forward is to use a preformed Cavitray. When horizontal preformed Type C Cavitrays are used with lintels, one eliminates the variances of a site-fabricated approach. Preformed Type C Cavitrays are ready shaped to harmonise with the window head construction/lintel choice, so the build detail is always consistent and correct. Type C Cavitrays are www.cavitytrays.co.uk n January, Delta unveiled its new Basement Drainage Distribution Hub, which comprises 3500ft2 of space dedicated to basement drainage-related products, from package pump stations, high-water level alarms, control panels, battery backups to pipework and fittings, supporting the team’s ability to meet the growing demand for quality basement drainage items. In addition to the increased space, the warehouse features modern staff facilities and a dedicated training and breakout space. o explore the new range of Delta pumps, visit the package pumps and basement drainage systems section on Delta Membranes’ website. hatever the needs of your project, you can rely on Delta’s technical team to ensure you get the right advice, support and practical help at exactly the right time it’s required. enquiries@cavitytrays.co.uk

Importantly, Type C Cavitrays have extended ends that project each side of the wall opening by 300mm. These extended ends serve two purposes. Firstly, they ensure adequate shelter of whatever reveal closing method is deployed. Secondly, the 300mm projection guarantees a brick perp joint beyond the opening is always located to accommodate the stopends in the optimum position.

“ The Delta V3, V4, V6 and V3 foul chambers had their origins almost 20 years ago. The industry has substantially changed with an emphasis on continuous waterproofing approaches and reducing risk. Delta is at the forefront of encouraging and promoting best practices. We believe in sharing our vision and clear performance metrics with our customers.

“ Delta’s approach is to share both our technical knowledge with product data in a clear, concise and consistent fashion.

“ We haven’t just reinvented a product or two; we have reinvented our product range to meet industry needs. The wheel has been reinvented thousands of times to serve thousands of different purposes. It had to be reinvented because it was being used for different purposes. The world changes from technologies to expectations. As the world changes, we need new and various kinds of wheels to help us solve the same problems.

Interestingly, if one looks at BS 8215, fig 15, it illustrates a perp joint naturally occurring to accommodate a stopend, 112.5mm beyond the opening. But if a whole standard 225mm brick occurs (there’s a 50/50 chance it will), the detail depicted is not possible.

U sing a preformed DPC tray with extended ends ensures appropriate perps are accessible, thus eliminating the problem.

Our new distribution hub will significantly increase Delta’s capabilities in terms of stock handling and storage. It will also allow us to reduce lead times on all basement drainage products, including our bespoke range of packaged pump stations.

NHBC 6.1 D6. B refers to window and door openings having an external turn-down drip lip. Whilst difficult to form using roll DPC, where a preformed tray is used, an external lip is one of many options available to the specifier/contractor.

Cavitray scheduling is straightforward – the company does it for you. Trays are delivered packaged per plot, so stock and cost are controlled. Importantly, a consistent build detail is achievable, every time.

There’s a CPD silent study tutorial that provides more information and some interesting data. You can access this access by visiting: www. directcontactexhibitions.com, selecting CPD academy and pressing Cavity Trays 3.