JCW Overfloor Standard System

Based on our popular JCW Acoustic Impactalay product, which features an acoustic foam resilient layer laminated to a single layer of acoustic barrier mat, the JCW Overfloor Standard System is designed primarily to combat impact and airborne noise on concrete floors.

However it also works well on other types of floor.

Although this product is a quick and economical and concrete floor solution, customers looking for peak performance against impact and airborne sound should also consider JCW Acoustic Impactalay Plus which can be used with great results on both concrete and timber floors.

Because the product is so effective and yet slim, there is minimal loss of floor to ceiling height.


About the product

The composition of the product at the heart of this system, JCW Acoustic Impactalay features an acoustic foam resilient layer laminated to a single layer of acoustic barrier mat.

Together these 2 layers of rubber absorb and insulate against the impact sound generated by foot traffic and also provide an additional sound barrier against loud talking, music and other airborne sounds.

At the same time as acting as a superb carpet underlay, the acoustic foam of the central resilient layer will not harden and crumb like lower quality underlay and is an ideal acoustic solution for concrete or solid floors, but also copes well improving the acoustic performance of  modern laminated, engineered wood and solid timber floors.

Product summary and benefits

  • All in one product with excellent impact and good airborne sound reduction
  • No need to lift floorboards
  • Works well on concrete and solid floors but can also be used on solid timber and laminated wood floors
  • Ideal as a quality carpet underlay
  • Works in all types of room and dwelling (widely used in new build, refurbishment, change of use, conversions, commercial and residential apartments)
  • Minimal impact on available floor to ceiling height – at just 12mm thick
  • Suitable for all final floor finishes
  • Meets and easily exceeds acoustic requirements of Building Regulations: Approved Document Part E (England & Wales) and Section 5 (Scotland)
  • Supplied in easy to handle, lay and install slab form. Easy to cut and shape

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    Technical Specifications


    • Standard size: 1200mm x 1000mm x 12mm
    • Standard Density: 10.25 kgs per m2
    • Sheet or slab weight: 12.30 kgs

    Acoustic performance

    Impact Sound Insulation / Concrete Floors Airbourne Sound Insulation / Concrete Floors
    JCW Impactalay 38 dB 49 dB
    Building Regulations Min requirement 64 dB 43 dB


    For full details of acoustic performance requirements for “dwelling houses and flats” and “rooms for residential purposes” go to Building Regulations Acoustic Requirements.

    Ancillary products

    • JCW Waterproof PVA Adhesive
    • JCW Acoustic Sealant and Applicator Gun
    • JCW Impactalay Perimeter Gripper Strip (6mm thick x 30mm wide x 1m long)
    • JCW Impacta Adhesive

    At a glance guide to help you calculate what you’ll need for the JCW Overfloor Standard Soundproofing System

    You can quickly work out how much soundproofing products and ancillaries you’ll want if you use this at a glance guide to calculate things. Check the square metre dimensions of the area to be treated and apply to the tables below

    Floor Area in m2
    JCW Impactalay Sheets (sheets/coverage m2) JCW Ancillaries
    3 3 (3.6) TBD
    4 4 (4.8) TBD
    5 5 (6.0) TBD
    6 5 (6.0) TBD
    7 6 (7.2) TBD
    8 7 (8.4) TBD
    9 8 (9.6) TBD
    10 9 (10.8) TBD
    12 10 (12.0) TBD
    15 13 (15.60) TBD


    Note: Where TBD is shown above, please discuss your plans with our Sales Advisor who will be please to recommend the appropriate quantities required for your project.

    Remember, you may need to add extra materials to cope with mistakes and mis-measures, so we advise you think seriously about allowing for wastage and off-cuts.

    DIY Installation Guide for laying JCW Impactalay

    Incorrect installation techniques and materials can compromise the integrity of any acoustic solution. Please follow this general guidance to avoid any incorrect installation which could have an adverse effect on acoustic performance.

    • Step 1: Remove all existing floor coverings.
    • Step 2: If the revealed timber floor is a suspended floor (not tongue and grooved floorboard), check by inserting a thin bladed knife through the gap: if the knife goes through easily without resistance, the floor boarding used will be “square jointed”. This gap will firstly need to be sealed with JCW Acoustic Sealant to avoid noise leakage through and into/out of the room. This must be done before proceeding to lay JCW Acoustic Impactalay. Step 2 is not relevant if the floor to be treated is concrete.
    • Fitting as Carpet Underlay using standard Gripper Rods
      Glue JCW Impactalay Perimeter Gripper Strips around the perimeter of the room. Nail carpet gripper rods in place on top of the Gripper Strip, taking care not to compress the Gripper Strip.

      Loose lay JCW Acoustic Impactalay sheets in brick bond pattern and tightly bond against the Gripper Rod/ Gripper Strip. Take care to ensure there are no gaps between the JCW Acoustic Impactalay sheets.

    • Fitting under Vinyls or Bonded Carpet
      Bond JCW Acoustic Impactalay to the sub floor in a brick bond pattern using JCW Impacta Adhesive. Sheets should be butted up to the perimeter wall/skirting.

      Then adhesive bond a layer of 9mm tongue and groove (t&g) MDF on to the JCW Impactalay taking care to ensure that the joints do not coincide. Bond the t&g joints using JCW Waterproof PVA Adhesive. Leave a minimum isolation gap of 5mm between the MDF layer and the perimeter wall to avoid flanking sound transmission. Then fill the 5mm gap with JCW Acoustic Sealant.

    • Fitting under Timber Floor Finishes
      JCW Acoustic Impactalay can be used under timber floor finishes but its suitability should be confirmed with the floor finish manufacturer before installation.
      If the manufacturer or installer considers that movement underfoot could be excessive, use a 9mm t&g MDF or 6mm butt-jointed plywood layer (follow steps as in Vinyls or Bonded Carpets guidance above).
    • Fitting on Stairs
      Cut the JCW Acoustic Impactalay to the correct size and bond to the stair tread (and riser) as required using JCW Impacta Adhesive. Use JCW Impactalay Perimeter Gripper Strip and gripper rods where necessary. Where a nosing detail is specified, fit a 15mm thick section of timber under the nosing to ensure the correct height.
    • General use under units, fixtures and fittings
      When kitchen or bathroom units need to be fixed to the floor they should be mounted on to a 15mm timber plinth and the JCW Acoustic Impactalay butted up to the plinth. This will ensure a consistent floor height.

    Note: Before using any adhesives or other bonding materials to fix your choice of final floor finish to the JCW Impactalay, please refer to the manufacturers recommendations and guidance. Use only those products recommended by the manufacturer that are considered suitable. When in doubt, contact the manufacturer.

    Professional Installation Service available

    For customers who need or prefer it, Soundproofyourhome offers a professional acoustic installation service across the UK.

    Our skilled and experienced tradesmen understand acoustic materials and how to fit them quickly and correctly.

    The result is a cost effective service and peace of mind about the acoustic integrity of your project. Contact us today for a free quotation.

    Soundproofyourhome is the domestic market operations division of JCW Acoustic Supplies Ltd, the UK’s leading manufacturer and distributor of soundproofing, sound insulation and sound absorbing products.

    Sound advice from Soundproofyourhome:

    Contact us today and tell us more about the noise problems you are experiencing. Our friendly, helpful advisors will offer you the most appropriate acoustic solutions available to meet your acoustic needs and budget from our comprehensive range.

    We believe talking about your situation and offering sound advice based on our vast experience in the acoustics business is a more reliable way of solving your noise problem than simply taking your order or selling “off the screen”, as some companies do.

    And if you are in any doubt about issues associated with soundproofing, like weight of materials, structural strength or meeting Building Regulations, then please talk to us – we’ll be happy to help.