Jack-Up Floating Floor System

Why Choose a Jack-Up Floating Floor?

The biggest advantage of a Farrat Jack-Up Floating Floor System is that isolation is guaranteed as the whole slab is lifted. There is no opportunity for any debris to be left in the cavity and any bridging is broken when the slab lifts.

The acoustic and structural performance of a Jack-Up floating floor is exactly the same as the equivalent non-jacked up system. The increased cost and installation time is only necessary in a few specialised circumstances:

  • A very low or adjustable air-gap is required
  • It is deemed likely that the isolators may need to be replaced in the future
  • The slab is required to take high loads (e.g. used as a storage area) before it is raised

Farrat Jack-Up  Floating Floor System

  • Jack-Up Floating Floors comprise of a concrete slab which is poured on a damp proof membrane on the structural slab. The slab is then ‘jacked’ up by way of units cast into the slab. They are favoured by acoustic consultants because of the certainty that the slab is fully decoupled from the surrounding structure.
  • Jack-Up floor slabs must be made from concrete and reinforced using mesh rather than fibres as the Jack-Up mounts are designed to link with the mesh to spread load when the slab is lifted.
  • A traditional Concrete Floating Floor System will be the most cost effective option as the acoustic performance characteristics of the two systems are identical.
  • However, in special circumstances, a Jack-Up Floating Floor slab can provide a number of key advantages including;
    • a low height and/or adjustable air-gap
    • replaceable isolators
    • the ability to take very high loads before jacking up (so the area could be used as a storage area during construction).

For more information on using a Jack-Up Floating Floor System (including standard details), please download our Farrat Technical Brochure:

Typical Applications:

  • Dance Studio
  • Gyms
  • Operating Theatres
Floating floors to isolate dance studios
Floating floors to isolate operating theatres

Typical Applications:

  • Sensitive Medical Equipment Rooms
  • Nanotechnology Facilities
Floating floors to isolate gyms
Floating floors to isolate reverberation chambers
Step 1
  • Undertake a level survey taking measurement points where Jack-Up boxes are to be placed
  • The structural slab should be within ±10mm. Low points can be accommodated by adjustment in the Jack-Up mount or by using packers, however high points must be ground down
  • Make sure surfaces (floor & perimeter walls) are dry and clear of lumps of concrete (remove anything larger than 10mm as they may break through the DPM)
  • Construct perimeter formwork if required. Typically this should be 25-50mm higher than slab thickness.
  • Bond perimeter isolation strips to any permanent interfaces (perimeter walls, service protrusions etc)
  • Height should be from the floor to the final datum
Step 2
  • Mark out grid lines for Jack-Up boxes, then place clear damp proof membrane (DPM) (either 1 layer of 1000gms or 2 layers of 500gms laid at 900 to each other) as a bond breaker under and around all edge faces of a jacked-up slab
  • All joints are to be overlapped by at least. 300mm and taped using min. 50mm wide Farrat DPM joint line tape
  • DPM must be fitted neatly into corners and edges to avoid localised slab thickness reductions
Step 3
  • Place Jack-Up boxes onto grid and reinforcement mesh to correct height to cover the entire area making sure it is brought right to the edges and corners of the slab
  • In order to maintain the correct cover on the mesh the Jack-Up boxes may have to be rotated by 900 to support the upper mesh bar
  • Tie wire all mesh sheets together every 400mm
  • Mesh MUST NOT damage/tear any of the DPM. If it does repair with extra DPM and tape
  • Some Jack-Up boxes may have to be moved slightly to fit into exact mesh grid to avoid cutting mesh
Step 4
  • Final check that boxes are within ±10mm, that mesh is supported in between boxes and that there is no DPM damage

  • Pour concrete taking care not to dislodge or tip any Jack-Up boxes. If this occurs correct immediately.

  • Power float if required taking care not to dislodge or tip any boxes. Alternatively trowel finish with screed layer on top to provide finished levels and cover exposed Jack-Up box tops.

  • If the perimeter formwork is to be removed, we suggest doing this within 48hrs of the concrete pour.

Step 5

Leave slab for 2 to 4 weeks to allow concrete to reach adequate strength.

  • Jack-Up slab according to project specific instructions.
  • This is a time consuming process, allow time for doing this (at least 2mins/m2mm).
Step 6

If any isolators need to be replaced through overloading or change in use then do one isolator at a time, remove Jack-Up box cap, unload bolt, replace isolator and re-tighten the bolt.

Bespoke Design Service

Jack-up Floating Floors are bespoke designed for each project/application. Please get in touch on the details below to discuss your requirements.

Farrat Floating Floors

  • Are used in a wide range of buildings to protect sensitive areas from noise sources or to contain noise sources within their areas
  • Offer flexibility in delivery as well as being easy, fast and economical to install
  • Provide a high degree of impact, shock and vibration control through a combination of mass addition and structural decoupling by constructing the floating slab on elastometric or coil spring isolators tuned to specific frequencies
  • Provide a high degree of airborne noise isolation through the incorporation of an air layer between the structural slab and the floating slab
  • Offer unparalleled flexibility in design, layout, acoustic and load carrying capacity
  • Are laboratory tested to national and international standards
  • Are supported by Farrat’s specialist team of structural and acoustic engineers

Standards & Compliance

  • Elastomeric Compounds & Isolators Our compounds conform with the requirements and testing procedures set out in BS 6177:1982 and BS EN 1337-3:2005. 
  • Acoustic Testing Our acoustic floating floor systems have been laboratory tested in accordance with BS EN ISO 140-4 & 7:1998 in a UKAS accredited laboratory. Full test data is available on request.
  • Quality Assurance Farrat Isolevel Ltd operates an ISO 9001:2015 approved quality assurance system.
  • Sustainability Farrat takes sustainability and environmental responsibility very seriously. Before each project, we undertake a waste mitigation exercise to limit the amount of waste we generate by effective planning. We use FSC/PEFC certified timber (Breeam Tier 3) and recycled aggregates in our CEM II/III concrete (Breeam Tier 3) meaning we can ensure you have the ability to achieve the maximum amount of credits under Breeam MAT 03.

All of the materials we use in our floating floors are 100% recyclable.

For free technical advice, an onsite visit, specification details or a quotaion, call us now:

+44 (0) 161 924 1600

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