JCW Impacta 4551

soundproof acoustic underlay matting on a roll

JCW Acoustic Impacta 4551 is a robust acoustic underlay material sold in an easy to handle roll. It is manufactured from recycled rubber, bonded with cork granulate and is designed to reduce impact sound at source.

It is available in 3mm thick rolls to give an acoustic performance of 19 dB or 4.5mm thick rolls to deliver a 21 dB improvement in acoustic performance.

It can be laid on all types of sub floor like concrete, asphalt or timber and will make an immediate difference to the level of impact sound on all final floor finishes, including ceramic tiles, vinyl, wood and laminates, carpet and marmoleum.

It can also be used with underfloor heating.

One of the most economical and adaptable of acoustic materials, JCW Impacta 4551 has a host of benefits.

In addition to being suitable for use on all types of sub floor and as an acoustic underlay for all types of final floor finish, it is incredibly quick and easy to install, offers long term market leading performance and is made from 100% recycled materials.

JCW Impacta 4551 complies with Part E of the Building Regulations.


Product summary and benefits

  • Slim all-in-one product with excellent impact sound reduction
  • Works superbly as an acoustic underlay on concrete, timber and asphalt floors where impact noise is the main identified problem
  • At just 3mm or 4.5mm thick this product is an ideal solution where floor height is a critical issue
  • Complies with the acoustic requirements of Building Regulations: Approved Document Part E (England & Wales) and Section 5 (Scotland) and meets Floor Type 1 Soft Floor Covering Specification
  • Excellent remedial solution
  • Supplied in easy to handle, lay and install roll form. Easy to cut and shape
  • Environmentally friendly recycled rubber bonded with cork granulate, with zero ODP (Ozone Depletion Potential) and zero GWP (Global Warming Potential)
  • Ceramic tiles can be laid directly onto JCW Impacta 4551 using JCW Acousti- Bond Tile Adhesive
  • Suitable for use with under floor heating

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    Technical Specifications


    • 3.0mm thick x 1050mm Wide x 20m Long Roll.
    • Weight per Roll 44.1 kgs
    • Coverage 21 square metres
    • 4.5mm Thick x 1050mm Wide x 10m Long Roll.
    • Weight per Roll 34.5 kgs
    • Coverage 10.5 square metres

    Acoustic performance

    JCW Acoustic Impacta 4551 options
    Impact Sound Insulation/Concrete Floors
    JCW Impacta 4551 3.0mm Thick 19 dB
    JCW Impacta 4551 4.0mm Thick 21 dB
    Building Regulations minimum requirement 64 dB

    Impact sound performance measured in accordance with BS EN ISO 140 – 8: 1998

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


    How much will you need? – See the product specification detail above for coverage information per roll, per thickness to calculate how much you will need. Alternatively, speak to our sales advisor.

    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. Please ask for advice.

    DIY Installation Guide for JCW Acoustic Impacta 4551 Soundproofing Acoustic Mat

    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: Ensure the sub floor is clean, dry, sound and smooth before the laying of JCW Acoustic Impacta 4551 acoustic matting commences
    • Step 2: JCW Acoustic Impacta 4551 stretches slightly when rolled up – so it must be unrolled and left for approximately 8 hours to condition to its environment before it is measured or cut. It is advisable to leave a gap of approximately 5mm around the perimeter to allow for expansion as the mat fully adjusts to the room temperature. Once the product has settled, fill any remaining perimeter gap with JCW Acoustic Sealant
    • Step 3. JCW Acoustic Impacta 4551 can be easily cut with a craft knife and straight edge
    • Step 4. JCW Acoustic Impacta 4551 is bonded to the sub-floor using JCW Impacta Adhesive and all edges are butt jointed
    • Step 5. When laying JCW Acoustic Impacta 4551, press outwards from the centre of the roll to maximise contact between the adhesive and the mat
    • Step 6. To achieve best results and maximum adhesion, roll over the whole of the laid area with a weighted roller once the JCW Acoustic Impacta 4551 has been bonded as in Step 5. Rollers are available from most tool hire shops nationwide and are water-filled to a weight of approximately 68kgs
    • Step 7. The joint edges can also be firmly secured by using JCW Black Cloth Edging Tape to secure them in position if needed
    • Step 8. Wait for approximately 30 minutes after the first rolling and roll again. Ensure the adhesive has fully set before the final floor finish is laid. If a carpet finish is to be installed, use Gripper Rod
    • If overlaying with ceramic tiles – we recommend you use JCW Acousti-Bond Tile Adhesive to maintain the acoustic integrity of the installation

    Note: before using any adhesives or other bonding materials to fix your choice of final floor finish to the JCW Acoustic Impacta 4551, please refer to the manufacturer’s recommendations and guidance. When in doubt, contact the manufacturer.

    JCW Ancillary Products you may need for this solution – check with your Soundproofyourhome sales advisor for details and quantities

    • JCW Acoustic Sealant
    • JCW Impacta Adhesive
    • JCW Impactalay Perimeter Gripper Strip
    • JCW Black Cloth Jointing Tape

    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.