Natural insulation

Natural insulation products have many properties that set them apart from conventional materials. Overall, their impact on the environment is much less than that of conventional insulation products. All-natural insulation materials are made from renewable plant or animal sources; their manufacturing processes use very little energy; they are safe for installers and pleasant to handle, and they are reusable or biodegradable at the end of a building’s life.

cutting WoodflexOnce installed in buildings, the benefits of natural insulation materials are even more marked. They have the ability to ‘breathe’, meaning they can absorb airborne moisture (resulting naturally from human activity and the weather) and release it again when the air is drier, keeping the relative humidity in the room stable, at a comfortable level for the occupants. Flax insulation, for example, can hold up to 25% of its weight in water before starting to lose its thermal capacity. This reduces the risk of condensation since the insulation acts as a reservoir.

This quality also helps to protect the building structure from damage through condensation and moisture, especially if it is timber, by wicking the moisture away from the wood. Natural insulation products are therefore ideal for use in ‘breathing’ constructions.

Additional benefits of natural insulation materials are effective sound insulation and the ability to perform over time, qualities not always achievable with conventional insulation products. The immediate performance benefits and longer-term cost benefits will, therefore, be significant.


HOMATHERM flexCL 040 is a very practical insulation material in flexible batt form, made from recycled newspaper and recycled jute sacking. The material is treated with borax to resist insects and to make the insulation fire-resistant. The material is very comfortable to work with and can be readily cut to fit where necessary. Installation is safe and easy, protecting the health of both installers and building occupants.

laying Karphosit clay blocksHomatherm improves the climate in the building because of its thermal and vapor diffusion capacity – the ability both to regulate temperature and to absorb moisture and gently give it off again. It protects the structure and keeps it dry, prolonging the lifetime of the building fabric.

Homatherm can be used between rafters, joists and timber studs in breathing constructions. It can also be installed as a partial fill insulation for cavity wall construction with a ventilated air gap.

Composition & Manufacture

  • Contains over 90% recycled material
  • No toxins or toxic emissions during manufacture

Installation & Disposal

  • No health risks for workforce or installers
  • Easily cut to shape
  • Flexible in all directions
  • No VOC emissions
  • Helps to avoid the use of treated timber
  • Durable / Low maintenance
  • Reusable / actively recycled


  • Excellent thermal performance in Winter
  • Excellent thermal performance in Summer
  • Excellent low-frequency acoustic performance
  • High vapor permeability
  • Hygroscopic (absorbs & releases moisture)
  • Absorbs harmful VOC’s and toxins
  • Vermin and fungus resistant
  • Electrically neutral
  • Non-radioactive
  • Free from toxins and allergens
  • Dimensionally stable (low thermal movement)

Happy Step

Happy Step is an internal floor wood-fiber insulation board that is laid below floor finishes, such as timber, carpet or cork. It provides resilience, impacts sound insulation and warmth underfoot. Its 6mm thickness makes little intrusion on floor levels and is therefore useful for retrofitting, as well as for discreet new installations. The boards are easily laid by professional or DIY installers.

laying Karphosit clay blocks

Under carpet

Glue-fix Happy Step onto the base floor (do not nail), then glue-fix the carpet onto the Happy Step or nail through to the base floor. Not suitable for roller chairs, or heavy point loads. Under short pile or thin carpets, the board joints may be slightly visible.

Under timber / parquet / laminate floors

Lay Happy Step onto the base floor without fixing. Lay a floating timber floor, without through-fixing, according to manufacturer’s requirements.

Under cork

Glue-fix Happy Step onto the base floor, then glue-fix the cork tiles onto the Happy Step using natural adhesives available from Construction Resources. Cork tiles to be at least 6mm thick.

Not suitable for use under lino.

Suitable base floors

Suitable for use onto concrete, screed, asphalt, timber floors, and sheet boarding. Base floors to be dry and even. Use a damp proof membrane under the Happy Step if the base floor is damp.


Happy Step can be cut with a sharp knife or carpet knife. Allow a 10mm space at the wall junction, which can be filled with an edge strip of Happy Step.


Regupol® is a tough, resilient sound insulation material used for underfloor impact sound reduction on all types of subfloors. It is suitable for all floor finishes including ceramic tiles, wood and laminates, carpet and linoleum, sheet vinyl and vinyl tiles, and between structural floor elements. Regupol® can be used to reduce noise on the stairs (4.5mm depth recommended). It can be used with underfloor heating.

Regupol® provides 25% reduction of surface sounds between 500 and 2.000 Hz. It is easy to install – simply bond to the subfloor beneath the final floor finish. It is temperature resistant from – 40°C to +110°C.

Regupol® CR225 may be used under solid timber and laminate finishes, carpet, linoleum and vinyl (with a separating layer). Regupol® CR225 is made from recycled tire-crumb rubber and cork with a polyurethane binder. It is supplied in 1.15m wide rolls of 3mm and 4.5mm thickness.

Regupol® CR4515 is suitable for all floor finishes including ceramic tiles, solid timber and laminate finishes, carpet, linoleum, and vinyl.

Regupol® CR4515 is made from a cork and polyurethane foam mix and supplied in 1m wide rolls of 3mm and 4.5mm thickness.

  • Reduces floor impact sound – provides 25% reduction of surface sounds between 500 and 2.000 Hz
  • Suitable for use under ceramic tiles, solid timber and laminate finishes, carpet, linoleum and vinyl
  • Easy to install
  • Suitable for use with underfloor heating
  • Cork and recycled rubber content
  • Independently tested by a UKAS accredited laboratory for compliance with building regulations in accordance with Approved Document E 2003
  • Long term performance without collapse or “bottoming” out under high point loads
  • Resistant to aging and deformation

Under a carpet

As a carpet underlay Regupol® CR225 helps provide a resilient surface to walk on as well as effective impact sound insulation. The Regupol® CR225 should be glued to the subfloor, and the carpet loose-laid on top.

Under a timber floor

Regupol® CR225 is effective at reducing the impact sound of footsteps to the rooms below. It can be glued to the subfloor, or in strips along the top of floor joists, before installing a floating timber floor on top.
Any fixings that penetrate through to the base structure should be avoided in order to reduce the transmission of impact vibration. If necessary this can be achieved by introducing an intermediate floating plywood floor, 22mm thick with glued tongue-and-groove joints, onto which floorboards or parquet can then be fixed. To complete the process, strips of Regupol® CR225 should be glued around the floor perimeter to isolate the flooring elements from the walls.

Under linoleum

Regupol® CR4515 is suitable for use under linoleum and vinyl. (Regupol® CR225 may also be used under linoleum; however, a separating layer of 1200 gauge polyethylene damp proof membrane should be used, with a water-based adhesive which is suitable for the DPM). It should be glued to the level subfloor, and the linoleum may be glued on top.

Under ceramic tiles

Regupol® CR4515 should be fixed to the subfloor with a flexible cement adhesive. The ceramic tiles should then be fixed on top of the Regupol® CR4515 with flexible cement adhesive and grouted with a flexible grout.


Total coverage of Holzweg/ Volvox Natural Latex Adhesive (see information sheet H26) is recommended ensuring that, in wet floor areas such as bathrooms, the floor finishes are completely sealed.



Leave a Reply

Your email address will not be published.