Natural Insulation

    Holzflex Wood Fibre Insulation

    HolzFlex from Homatherm is a unique semi-rigid wood fibre insulation in slab form. The main raw material used to produce holzFlex is wood chippings. HolzFlex can simply be friction fitted between rafters, joists or studs and wedges itself in the studs almost independently because of its elasticity. Because there is no requirement for wearing awkward protective clothing when fitting and also because the product is easy to cut it can be installed effortlessly with no concern for harmful fibres. Even hard to reach hollow spaces can now be insulated thoroughly and effectively.

    holzFlex is ideally suited for timber constructions but it is also very suitable in traditional masonry constructions as drylining insulation. In timber frame constructions holzFlex is ideal as both the insulation slab and the timber frame compliment each other. With a thermal conductivity of 0.038W/mK holzFlex acts as a very effective thermal insulation layer. High elasticity and excellent draught proofing properties compliment each other superbly with holzFlex. holzFlex is not restricted by the width of the studs as each slab may be cut easily using a knife or handsaw.

    Buildings constructed from natural building materials offer a hitherto unachievable level of comfort, safety and energy efficiency. Similar materials complement each other in a construction. When holzFlex is used as an insulating material the result is a thoroughly homogenous healthy construction.

    • HolzFlex also offers superior heat protection to buildings in comparison to conventional insulation materials. This is particularly critical in timber frame buildings and dormer houses which suffer from intense overheating in the summer months.
    • HolzFlex also offers outstanding acoustic airborne sound reduction due to its density and natural flexibility. Whether installed in stud partitions between rooms or in ceiling joists between floors, holzFlex offers an incredibly effective, simple, natural acoustic solution to match the homeowner’s needs.
    • The hygroscopic nature of holzFlex woodfibre insulation allows for the rapid absorption of moisture when internal humidity is high. The moisture can in turn be released quickly when internal conditions are too dry. This feature is important in order to improve the health and comfort of the inhabitants and prevents the growth of moulds, fungi and dust mites.
    • HolzFlex has outstanding fire resistance properties. holzFlex does not emit noxious gases when exposed to a naked flame, nor does it degrade rapidly. holzFlex chars when exposed to a flame.
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    Technical Information

    Property Details
    Batt size 1250 x 570mm
    Batt Thickness 40/60/80/100/140
    Coverage per pack 5.7/3.5/2.85/2.13/1.425m2
    Insulation with the European Technical Approval BS-EN-13171-T3-T2.5-AF5
    Components 82-85% Wood fibres, 10-15% Polyolefin fibres, 3-5% soda for fireproofing.
    Free from Borax and Boric Acid
    Bulk Density Approximately 45/55kg/m3.
    Thermal Conductivity 0.038W/(m.K).
    Fire rating Class E
    Specific Thermal Capacity 2100 J/(kg.K).

    Fields of Application

    • Insulation between the rafters.
    • Insulation on the rafters and between supporting rafters.
    • Insulation under the rafters.
    • Insulation of wooden joists in ceilings.
    • Insulation of the internal and external walls in timber frame, and post and beam constructions.
    • Insulation of metal studded constructions or partitions.
    • Internal dry-lining insulation in the refurbishment of masonary/solid constructions.
    • Exterior insulation of walls with a well ventilated air layer.
    • The lower the vapour sealing effect achieved, the more this natural insulation material can deliver its range of advantages.
    • Ensure there is adequate ventilation during installation.
    • To ensure the installation is achieved without gaps (joints) please oversize the insulation with an extra 20-30mm relative to the void to be insulated.
    • Ensure a suitable sealed vapour check is applied and that the construction is sealed airtightly immediately after the insulation is installed.

    Measuring Up

    Deciding On Your Dimensions

    The dimensions of insulating material required are determined by the construction dimensions. To determine this, the space between rafters should be measured & 2-3cm should be added to the final measurements. These additional centimetres are used to avoid a heat build-up and will also allow for the clamping of the mats. Where the thickness of the insulation material is less than 100mm, the mats should also be tucked.

    Tool Requirements

    Small Quantities

    Holzflex can be cut to size with simple cutting tools like an insulating cutter. A long blade with a wave-like cut gives the best results.

    Large Quantities

    For this purpose an electric-handsaw with a wave-cut blade will give you the best results. (Bosh GFZ 16-35 AC).