Natural Insulation

Natural Insulation Choices in Home Construction

natural insulation from natural sourcesThe choice of the insulating material has a major impact on the indoor climate in all buildings.  Natural insulation materials made from renewable resources have similar properties during the cold of winter and even better insulating properties in summer heat than fossil (polystyrene) and mineral products (glass or rock wool).

In contrast to these, natural insulation materials are considered safe when properly installed, can store and release moisture and prevent mold.  Natural insulation materials are largely CO2-neutral, easy to recycle and conserve finite fossil fuels. 
Renewable raw materials are either vegetable or animal of origin, and come from agriculture and forestry.

Facts About Natural Insulation:

  • The manufacturing of insulating materials such as hemp or cellulose insulation uses only 10 percent of the energy needed for the production of mineral wool?
  • Some renewable resources have the ability, in some cases, to absorb up to 30% of its weight in moisture and release it again?

The following are some of Pacific Timberworks preferred natural insulation materials.

wood fibre insulation

Wood Fibre Insulation

Wood Fibre as a Commodity

The raw material (ingredients) of WFI are untreated wood chips from spruce, pine or fir from the wood manufacturing industry harvest from sustainable forests.


Wood fibre boards are produced in either a dry or wet-method.  In the wet process the wood waste is mechanically ground into fine wood fibres, heated and then pressed and cut into sheets. In the dry process, the wood fibres are ground and glued, pressed and cut into sheets.  Adhesives, depending on the intended use, come from the wood’s own resin as a binder. Other additives include white glue, wax and latex.


Wood fibre insulation provides effective protection against heat loss and street noise penetration. Another peculiarity of wood fibre insulation is its function against heat. The wood fibre insulation acts as a buffer memory which stores summer heat and slows the penetration into the house. Well designed insulation made with wood fibres hold the heat energy until the hot part of the day has subsided and then releases it back outside.
In addition, wood fibre insulation offers the advantage of counteracting the formation of condensation with natural open pores.


WFI is easy to handle and very universal for wall insulation (thermal insulation in the system), floor, ceiling and roof – rafter insulation as well as a roof panels, for example, for outside, windproof and vapor permeable moisture protection.


Thermal conductivity: 0,040-0,055 W/(m*K)
Spec. Heat capacity:  2.000-2.100 J/(kg*K)
Diffusion resistance: 5-10
Density: 150-190 kg/m3
Primary Energy: 600-1.500 kWh/m3

hemp insulation

Hemp Insulation


Hemp (Cannabis sativa L.) is an ancient crop  with the longest tradition of contributing to the supply of building materials, clothing, paper, fuel, clothing, oil and food. Even the Egyptians and the ancient Greeks wore clothes made of hemp.  Varieties cultivated for use in building materials have a very low amount of tetrahydrocannabinol (0.3%).  After a relatively short growing season of about 3.5 months the hemp plant reaches a height of up to 4 m and a mass of about 10-12 tons per hectare.  Through its relatively rapid growth, hemp quickly overshadows the ground thereby preventing weed growth so there is no need for chemical herbicides. With that rapid growth, hemp binds relatively large amounts of CO2 and since hemp insulation is made of 100% natural materials it is also compostable.

Production of Hemp Insulation

For the production of hemp fleece and insulation panels only the stalk of the plant is used and by adding sodium carbonate (salt), the fire rating of hemp insulation is raised.

Properties of Hemp Insulation

Hemp fibres open-pore cell structure absorbs moisture and realises it again when drying.
Since hemp inherently provides very little nutrition, it is resistant to critters such as mice or beetles.

Application of Hemp Insulation

Hemp is easy to handle and very universal for wall floor, ceiling and roof rafter insulation as well as roof panels that are vapour permeable and offer wind proofing and moisture protection.

Specifications of Hemp Insulation

Thermal conductivity:  0.040 – 0.045W/mK
spec. Heat capacity:  2.300J/kgk
Diffusion resistance:  1-2
Density:  30-42 kg/03
Primary Energy:  50-80 kWh/m3

flax insulation

Flax Insulation


Flax (Lignum) is one of the oldest cultivated plants and has been grown for many centuries as a food crop.

Production of Flax Insulation

Flax insulation is made from the stems of the flax plant by mechanical treatment. The flat, short fibres are used as an insulating material. These are processed by removing the base layer with Dutch needle rollers that are used in fabrics. Using starch as an adhesive, the sheets are glued together to make sheets of different thicknesses.  To protect against fire, moisture and pest damage the sheets are impregnated with boron salt.

Properties of Flax Insulation

Due to the moisture regulating properties of flax fibres they are particularly suited for the insulation of a breathable structure.  In addition to the positive characteristics for your indoor environment, flax is largely resistant to rot.

 of Flax Insulation

Flax is easy to handle and very universal for wall floor, ceiling and roof rafter insulation as well as roof panels that are vapour permeable and offer windproofing and moisture protection.
The seeds of the flax plant are used for the extraction of linseed oil, the main constituent of many natural oils for timber treatment.

 of Flax Insulation

Thermal conductivity:  0.040 – 0.045W/mK
spec. Heat capacity:  1.300J/kgk
Diffusion resistance:  1-2
Density:  20-80 kg/03
Primary Energy:  30-80 kWh/m3

wood chip insulation

Wood Chip Insulation

Wood Chips Insulation
Wood chip insulation consists exclusively of spruce, pine and fir wastes from sawmill planers.  Screened wood shavings and dust is sprayed with whey and soda or mixed with clay to form a homogeneous solution that fits around pipes and wires leaving no voids while maintaining the ability to absorb and expel moisture.

cotton insulation

Cotton Insulation

Under construction, information coming soon!

cellulose insulation

Cellulose Insulation

Cellulose Insulation


Recycled newspapers serve as starting material for producing cellulose. Other ingredients include boric acid and aluminium salts that are already added in production and protect against mold and fire.

 of Cellulose Insulation

Cellulose insulation is made as loose, blow-in insulation and in sheet form.  Other ingredients include boric acid and aluminum salts that are already added in production and protect against mold and fire.

Blow-in cellulose is made when waste paper is mechanically shredded and frayed. This changes the structure from scrap paper to a three-dimensional flake. To produce the cellulose in sheet form, the flakes are pressed under steam to form panels.

Properties and Application – Coming Soon!

Specifications of Cellulose Insulation

Thermal conductivity:  0.040 – 0.045W/mK
spec. Heat capacity:  2.300J/kgk
Diffusion resistance:  1-2
Density:  30-42 kg/03
Primary Energy:  50-80 kWh/m3

cork insulation

Cork Insulation


Basis of cork insulation is the bark of the cork oak (Quercus suber).  Since the 2nd century A.D. the cork tree has been peeled and processed.  It grows mainly in Southwest Europe and northwest Africa.  Portugal leads the production with a 50% market share.


 of Cork Insulation

Cork oaks, from an age of approximately 20 years will get peeled in intervals of 9-12 years.  As insulation, cork comes to use in the form of plates, loose fill or granular.  We distinguish between backed and press cork whereas backed cork is the more frequently used form of insulation, pressed cork is used as a flooring product.  To produce cork insulation, bark is peeled off of the tree and exposed to hot water vapour which increases the volume of the particles.  The released resin from the bark is usually enough to bond the granules into blocks and mats.
Recycled wine bottle corks are been reused with success.


 of Cork Insulation

Cork consists of closely spaced, dead, cells.  Up to 40 million cells per cubic centimetre. Therefore cork has a very high elasticity and compressibility and with very little weight. Overall cork is warm, sound absorbing, wear-resistant, flame retardant and resistant to moisture.

 of Cork Insulation

As insulation, cork can be used in cavities of exterior wall framing, partitions walls and surface insulation behind facade cladding or behind stucco.  In roof areas, cork can be used in the cavities in between rafters or on top of vaulted, timber frame roof structures. Due to the high compressive strength it is also suitable for below concrete subfloors. Cork granular is commonly used as cavity insulation in walls, roofs and ceilings.

Cork has also regained popularity as a floor covering.

Thermal conductivity:  0,040-0,055 W/(m*K)
spec. Heat capacity:  2.000-2.100 J/(kg*K)
Diffusion resistance:  5-10
Density:  150-190 kg/m3
Primary Energy:  600-1.500 kWh/m3

green roofs are a natural building method used by Pacific Timberworks

Grass Insulation

100% cellulose fibres derived from meadow grass is washed in a “washing machine” were it gets broken down into its components protein and cellulose. The cellulose fibres are then fitted in a special wet process and mixed with necessary fire retardants.

Meadow grass insulation is made from 100% natural cellulose. The Grass cellulose fibre is made fire safe during drying process in a special process.

This type insulation is suitable for blowing insulation into the cavities of ceilings, roofs and walls.  As with all the blow-in insulation is applied mainly in difficult to access areas in existing buildings.