Wood
Wood is a living material: it swells with humidity, shrinks in dry air and changes colour with light. Good furniture is built with that behaviour in mind.
Sitdesign sofa frames are built from kiln-dried beech.
Why kiln-dried beech for the frame?
Beech is a hard, close-grained wood (Janka hardness 6,460 N) that bends very well with steam. For furniture used indoors, the moisture content of the wood should be roughly 6 to 10%. Wood that has not been brought down to that level in a kiln carries on drying in the home: it shrinks, warps and the joints work loose. Kiln drying gets that movement out of the way before the frame is built.
Species
| Species | Hardness (Janka) | Density | Colour and grain |
|---|---|---|---|
| European beech | 6,460 N | 710 kg/m³ | Pale straw; straight grain, fine even texture |
| European oak | 4,980 N | 675 kg/m³ | Light to medium brown; coarse texture, pronounced grain |
| American white oak | 5,990 N | 755 kg/m³ | Light to medium brown; straight, coarse |
| American black walnut | 4,490 N | 610 kg/m³ | Pale brown to dark chocolate; medium texture |
| European ash | 6,580 N | 680 kg/m³ | Light to medium brown; grain similar to oak |
Solid wood or veneer?
| Solid wood | Veneer on a panel | |
|---|---|---|
| What it is | Wood in one piece | Real wood sliced from the log, about 0.6 mm thick |
| Strength | Can be sanded deeply and refinished | Stays flat on wide surfaces; the grain can be matched |
| Weakness | Moves across the grain with humidity; a wide top can split or cup | A deep scratch that goes through the veneer is hard to repair locally |
| Where it belongs | Frames, legs, edges | Table tops, doors, wide flat surfaces |
Veneer is real wood. MDF and plywood are standard practice in quality furniture as the base under veneer. E1 means the panel emits 0.124 mg/m³ of formaldehyde or less; from August 2026 the European Union limits furniture to 0.062 mg/m³.
Finishes
| Finish | Resistance | Repair |
|---|---|---|
| Oil or hardwax oil | Moderate; stands up to wine, coffee and water, but a spill left for many hours marks | Easy: re-oiled locally |
| Nitrocellulose lacquer | Moderate | Easy |
| Polyurethane or catalysed lacquer | High: best against moisture, scratches, heat and solvents | Difficult to repair invisibly in one spot |
How wood behaves
The ideal room is at 40 to 60% relative humidity. Swings in humidity do more harm than a steady level. Light changes colour: as a rule, pale woods darken and dark woods lighten. Walnut tends to lighten and warm over the years. A finish slows this down; it does not stop it.
Care
- Dust with a dry, soft cloth.
- Wipe up spills at once with a dry cloth.
- Use trivets under hot dishes and coasters under glasses.
- Keep away from radiators and out of direct sunlight.
- Do not leave the same object in the same place for months; it leaves a colour shadow.
- Lacquered surfaces: a damp, well-wrung cloth. Oiled surfaces: re-oil locally when needed.
Never use: silicone spray polish, detergent, abrasive pads, steel wool, bleach, acetone or steam.
Water rings. A white ring is moisture trapped in the finish and can usually be removed. A dark mark means water has reached the wood, and is a job for a professional.
Frequently asked questions
Is veneer real wood?
Yes. It is a layer of natural wood about 0.6 mm thick, sliced from the log.
Is solid wood better than veneer?
Each has its place. Solid wood suits frames and legs; veneer is more stable on wide flat surfaces.
Oak or walnut?
Oak is harder and coarse-grained. Walnut is darker, with a medium texture.
Will the colour of the wood change?
Yes. Pale woods darken and walnut lightens; a finish only slows it down.
Is MDF poor quality?
As a base under veneer it is standard practice. Its weak point is moisture getting in at the edges.
What does E1 mean?
A panel class with formaldehyde emission of 0.124 mg/m³ or less.