Hush - Felt 25
Resilient Joist Strip

Hush-Felt 25 has been designed as a joist treatment offering an economical alternative to composite floating flooring without compromising on performance. Used in the construction of floating floors layered over timber joists in new build and refurbishment projects. The integral hardboard slats present a firm, smooth surface to support a choice of chipboard, OSB or plywood T&G flooring boards. Excellent results are achieved when using Hush-Felt 25 as part as a sound insulation system between separating floors.


  • An alternative and economical joist treatment for use in many situations requiring impact sound insulation between separating floors.
  • Used extensively within refurbishment and new build projects as a component of floating floors over timber joists
  • Compatible with a range of Hush-Systems, designed to exceed the current Building Regulation requirements of Part E (England and Wales), Part H (Scotland) and Part G(Northern Ireland).
  • Comprises a double layer of 10mm Hushfelt™ resilient layer factory stapled to hardboard slats

Acoustic Performance - Typical test results*

Impact lntw dB
Airborne dntw dB
ctr dB

Test Data

Test data for field tests in compliance with Building Regulations Document E and laboratory tests complying with Robust Details can be supplied upon request.

Product Data

Directly over timber joists
140mm x 50mm hardboard slats
Double layer of 10mm Hushfelt™ resilient layer
Overall Strip Dimensions
25mm deep x 50mm wide
Weight per 1m
0.6 kg
Overall nominal thickness
Overall thickness in use
20-21 mm
Compatible Hush-Systems
Hush-System 1, Hush-System HF25, Hush-System HF25 Advanced
Accessories Hush-Seal 20 Perimeter Seal, Hush-Bond Panel Adhesive


1. Lay the strips end to end, hardboard pads upwards, and staple, through the Hush-Felt into the joist tops using 16mm staples. Do not fix through the hardboard pads. Allow for a perimeter noggin at the end of the joist runs on to which is installed a length of Hush-Felt 25.

2. When planning the floor layout leave a 10-15mm expansion gap around all perimeters. Apply a snake of Hush-Bond Panel Adhesive on to each of the hardboard pads and lay the flooring boards on top in broken bond fashion. At the same time the flooring boards should be glued at all teegee joints board to board.

3. Press Hush-Seal 20 Perimeter Seal into the perimeter expansion gap ensuring that the floor floats freely of the walls maintaining acoustic isolation.

No other fixings should be used when fitting the floating floor as any restrictions can adversely affect performance. Skirting should be fitted a minimum of two or three millimeters clear of the floor surface. (PCT only).

Full fitting instructions are supplied with all products and are available to download from the Installation Guides section.

Product Datasheets

Hush-Felt 25 Datasheet
Hush-Felt 25 Installation Guide
Hush-Product Brochure