The Comprehensive Guide to Firewood and Pellets
Everything you need to know about timber dimensions, residual moisture, optimal storage and the correct way to light a fire for maximum heating output with minimum consumption.
1. Understanding units of measurement for timber: cubic metres, solid cubic metres & loose cubic metres
When buying timber, many consumers come across different ways of specifying quantities. We’re here to clarify the matter:
Festmeter (FM)
Refers to one cubic metre of solid wood mass, excluding bark and any air pockets. It is mainly used in forestry in relation to round timber logs.
Cubic metre (RM / Ster)
A cube measuring 1 x 1 x 1 metre, made up of neatly stacked logs with minimal natural voids. Our standard size for pallets!
Cubic metre of bulk material (SRM)
Logs are poured loosely into a 1 m³ container. Due to the many large air pockets, 1 SRM corresponds to only approximately 0.6 to 0.7 cubic metres.
2. Types of wood & calorific value table
Hardwoods burn for a long time with a lovely glow, whilst softwoods quickly reach high temperatures.
| Type of wood / Fuel | Calorific value per kg | Burning time & flame pattern | Recommended use |
|---|---|---|---|
| Hornbeam / White beech | approx. 4.2 kWh/kg | Extremely long-lasting embers, hardly any flying sparks | Continuous-burning stoves, storage stoves, fireplaces |
| European beech | approx. 4.0 kWh/kg | A steady flame, an intense bed of embers | The ideal all-rounder for any oven |
| English oak | approx. 4.1 kWh/kg | Very long-lasting heat release | Tiled stoves, fireplace inserts |
| Wood pellets (DINplus) | ≥ 4,9 kWh / kg | Extremely high energy density, < 0.5% ash | Automatic pellet stoves & boilers |
| Hardwood briquettes | approx. 5.0 kWh/kg | Even combustion, space-saving | Rapid heating and heat retention |
3. The Swiss method: heating from top to bottom
Empty the base
Place two or three thick hardwood logs close together on the stove’s grate.
Fit the ignition module
Arrange 4 to 6 pieces of fine softwood (kindling) in a criss-cross pattern on top and place an eco-friendly firelighter between them.
Light at the top
Open the air supply fully and light the igniter at the top. The fire will slowly work its way downwards – with almost no smoke!