It is not uncommon to experience uneven substrates in both new and existing concrete floors, particularly in high-rise buildings where large sectional pours mean tolerances can be extremely varied.
As a result, installing the levelling compounds required can prove to be costly and time-consuming.
Installing an acoustic cradle and batten system provides a floor that is quick to install, lightweight and extremely accurate, enabling contractors to get the floors to within the nearest millimetre. The flexibility of the system also enables services to be run in the floor zone, as well as being suitable for underfloor heating systems, and will accept a multitude of floor finishes with very little preparation required.
Large apartment blocks, by their very nature, utilise large areas of concrete floors and getting the tolerances right can be challenging. Whether that is allowing for a camber in a hollowcore plank floor, or pouring insitu concrete slabs, a cradle and batten system can level up even an out of tolerance slab, or just be used as a lightweight way of raising floors. We have seen projects where the floors are out of tolerance by up to 30 mm in an apartment, and have had contractors ask for floors to be raised by 325 mm.
The system comprises certified softwood timber battens, supported by acoustic cradles with a high compressive strength rubber pad for impact reduction. The timbers are levelled using a combination of plastic packers and elevation blocks to offer flexibility in height adjustments, with the system designed to provide quick and easy installation.
Often there is a conflict between reducing impact sound through the slab, which by its very nature should have some flexibility, and the stiffness required for the use of brittle finishes such as large format ceramic or porcelain tiles. Extensive testing of the systems is required to provide specifiers, contractors and installers with the confidence that the system will perform, no matter what floor finish or acoustic performance is required in any given specification.
With underfloor heating becoming more prevalent in many new building projects, floors of this nature are not just looked upon to level uneven floors.
The global climate crisis is rightly bringing energy efficiency into focus, and having proficient heating systems is just one small part of how we are constructing more environmentally friendly homes.
This has seen a bigger call for overlay boards and floor finishes with low thermal resistance, ensuring a more responsive underfloor heating system that has greater controllability.
Further aiding flexibility, the systems are designed so that incorporating an underfloor heating system and a high-density gypsum overlay board is simple. Installing insulation and diffuser plates in between the timber battens means the heat is transferred upwards with very little resistance from the overlay board meaning the heat is transferred into the room quicker. Heat transfer can cause its own issues however, with chipboards traditionally having high levels of expansion and contraction with changes of temperature. High-density gypsum boards do not have this issue, and so installing tiles, vinyls and wood flooring has never been easier.
Engaging with stakeholders
As with any system, engaging with the stakeholders of the project is key to eliminating possible issues or time delays on site. Issues such as metal frame facades, high point loads for projects such as schools or hotels and fire detailing all have simple solutions if thought about from an early stage in the build process.
A lot of the issues we see on sites using raised floor systems can be overcome very easily, however, it is critical that these are identified at an early stage so that we can work together to offer solutions. It may be as simple as bringing in the centres of the batten system for corridor areas or kitchens and bathrooms that typically experience higher loadings, but even the simplest solutions can seem trickier if they are dealt with ‘last minute.’
A recent project in London highlights many of the points discussed in this article. Over 12,000 m² of acoustic cradle and batten was installed, incorporating underfloor heating, with most of the floor finished with 600 x 1200 large format porcelain tiles. It was important on this project that consultation was undertaken with the architect, tile manufacturer and tile installer at an early stage to find a balance between the needs for acoustic performance while minimising deflection.
The system was rigorously tested at a UKAS accredited laboratory to confirm that the overall level of deflection met the stringent requirements from the customer. The flooring and underfloor heating contactor were also engaged and trained with the improved acoustic system, and the installation incorporated a cantilever solution at the glazed facade which accommodated differing floor void heights, also requiring increased loading to kitchens and corridors. This did have an effect on how the underfloor heating zones were to be fitted, so again consultation prior to the start of the works was so important in order to maintain output and overcome potential snags before they happened.
Peter Rigby is key account and supply chain manager at Cellecta