product details

Various (See bottom of page)

PRICES technical data acoustic test report health & safety data Install guide DOWNLOAD PDF

key benefits

soundproofing: Thermafleece Ultrawool- Environmentally friendly Acoustic Insulation
sheets of Thermafleece acoustic insulation
man installing Thermafleece into loft Thermafleece with sheep

sheets of Thermafleece acoustic insulation


Thermafleece acoustic insulation is a greener alternative to normal Rockwool type acoustic mineral wool and is manufactured in the UK using sheep's wool.  It offers first-class acoustic performance in cavities of buildings whilst minimising impact on the environment.


Thermafleece meets the highest quality and performance standards and is the only wool based insulation to hold BBA certification for its thermal insulation properties and can be used to meet Part E when converting properties into flats or new build.  Thermafleece acoustic insulation is an environmentally friendly solution that utilises natural hollow wool fibres, blended to an optimum density producing first-class acoustic performance in buildings whilst minimising impact on the environment. This naturally occurring and sustainable environmentally friendly product is the alternative to Rockwool type products when looking for a green substitute to infill stud partitions and timber joisted floors for sound control.

This product was initially developed as very effective thermal insulation. However, it has now been found to have excellent sound absorbing qualities without the itchiness that mineral wool products give. However, if you prefer to use a mineral wool type sound absorber for your stud partition or floor joists then use our Rockwool type acoustic mineral wool or for greater performance, our SoundBlocker Quilt again produced from sheep's wool for more severe noise problems.

Why Thermafleece as a Sound Absorbing Infill?

Environmentally friendly sound control in a property will significantly reduce the amount of energy consumption and carbon dioxide released to the atmosphere as created by alternative mineral wool type insulation. Sheep’s wool is a sustainable and functional complex fibre with unparalleled insulating properties, designed by nature to insulate sheep in the harshest of environments, making wool the ideal natural fibre to use for acoustic insulation.

First-class performance

Not only does Thermafleece provide excellent thermal insulation in a wide variety of constructions, it can be used in many acoustic applications. Thermafleece acts in sympathy with your property absorbing many indoor air pollutants and helping control humidity levels.

Long lasting

In order to ensure consistent acoustic performance, it is important the insulation retains its shape throughout its service life. Thermafleece contains a lofting agent to maintain fibre stability and ensure the acoustic batts maintain structural integrity throughout their lifetime. The manufacturing process ensures that each acoustic batt is composed of a random matrix of wool fibres that will not split or delaminate in service.


Thermafleece is the only wool insulation to be certified by the British Board of Agremént (BBA). Certification by the BBA ensures Thermafleece is manufactured and performs to a rigorous set of standards. The certification covers installation between joists in ventilated and unventilated lofts; under pitched roofs and between rafters for tiled or slated pitched roofs, as well as timber frame wall applications between studding with a weather resistant cladding, and a ventilated and drained cavity.

Environmental Excellence

Using Thermafleece can reduce carbon emissions by many times over the lifetime of use. In addition, the wool fibres absorb carbon dioxide from the atmosphere helping reduce atmospheric greenhouse gas levels and making Thermafleece one of the most sustainable building materials currently available.


Thermafleece with two sheep on hilllside


 Thermafleece is safe to handle without the need  for personal protective equipment. It does not  scratch or abraid when handling and does not  cause any itching of the skin. In fact it is a joy to  handle and once used, will always be the preferred  option when looking for an effecting sound  absorbing infill.



What sizes are available?

Thermafleece is manufactured in batts full details are shown below.

Batt Dimensions(mm) Density (Kg/m3) m2 per Pack Pack Volume (m3) Pack Weight (kg)
50 x 400 x 1200 25 20.16 1.008 25.2
50 x 600 x 1200 25 20.16 1.008 25.2
70 x 400 x 1200 25 12.96 0.972 24.3
70 x 600 x 1200 25 12.96 0.972 24.3
90 x 400 x 1200 25 10.08 1.008 25.2
90 x 600 x 1200 25 10.08 1.008 25.2