What is softboard?
Softboard (also called insulation board or low-density fibreboard) is a soft, lightweight board made of pressed wood fibres. Usually no glue is added during production: lignin, a natural substance in wood, binds the fibres together. Softboard belongs to the same family as hardboard and MDF but is pressed far less densely. In the European classification of fibreboards (EN 316), softboard is the lightest type; the requirements of EN 622-4 apply to boards with a density of 230 to 400 kg/m³.
Properties
- Light and soft: easy to cut with a handsaw or a sharp utility knife.
- Insulating and damping: the open structure reduces impact sound and gives some thermal insulation.
- Levelling: it absorbs small irregularities in the subfloor.
- Sensitive to moisture: it absorbs water and can swell or warp.
- Combustible: as a wood product it adds to the fire load.
Application
Softboard is mainly used as an underlay beneath laminate, engineered wood and other floating floors, where it levels the subfloor and reduces footstep noise. In the past it was widely used for ceilings and as pinboard. Thicker wood fibre insulation boards, used for thermal insulation in roofs and walls, are a related product with their own standards.
Tips for use
- Acclimatise: store the boards in the room where they will be laid for one to two days.
- Vapour barrier on concrete: on a concrete or sand-cement screed, lay a membrane first as specified by the flooring manufacturer.
- Avoid heavy point loads: softboard is too soft under heavy furniture on small feet or under tiles.
- Check fire safety: make sure the application (for example as a ceiling lining in an escape route) meets local fire regulations.
- Stagger the joints: lay the boards in a staggered pattern with tight butt joints.
Related terms
- Hardboard
- MDF
- Chipboard
- OSB board
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