Log storage methods, costs and a yard decision checklist

Once you know the biological limits, storage becomes a choice between keeping logs dry, keeping them wet or moving them fast. Figures below are from Bavaria (LWF, 2014 and 2025) and North America (Wood Handbook) and are not transferable without checking local permits and conditions.

Dry storage

In-bark dry storage works only for a few weeks for winter-felled wood. Spruce must leave before the bark beetle flight (March or April, depending on weather) or sit at least 500 m from conifer forest. Piles belong on shaded, wind-sheltered sites beside truck roads, on supports, secured against rolling, at most 4 m high. Debarked dry storage needs the opposite site (ventilated, dry, warm, unshaded); the LWF cites 1 to 3 years for debarked spruce. Debarking cost in Bavaria in 2025 was about 8.50 euro per Fm for long wood.

Wet storage and sprinkling

Wet storage keeps logs in the window where oxygen is too scarce (above about 120 percent MC). A 2014 Bavarian source (Lutze) requires 50 mm of water per day, a water-law permit, and reports practice of 3 to 6 years for spruce, at least 2 years for pine and about 2 years for beech (opened beech must be sawn within 1 to 2 days because of grey oxidation). The 2025 LWF leaflet gives:

• about 0.7 l/s per 1,000 Fm in interval operation,
• 1 ha per 15,000 Fm as the minimum economic site size,
• spruce 3 to 6 years, pine at least 2, beech only months,
• total cost of 18 to 20 euro per Fm per year, of which operation is 3 to 4 euro and freight about 80 percent.

The two documents use different units and reference areas, so do not compare them directly. Start and stop temperatures and pile height were not stated; take these from the local permit.

Worked example: a 15,000 Fm sprinkling site

• Flow while running: 0.7 l/s per 1,000 Fm x 15 = 10.5 l/s, which is 10.5 x 3,600 / 1,000 = 37.8 m3/h.
• Annual cost: 15,000 x 18 = 270,000 euro to 15,000 x 20 = 300,000 euro.

Wet storage has a use-by date

Engesser (WSL, 2003) reported that after storm Lothar (1999) the only fungus able to attack properly sprinkled wood was honey fungus (Hallimasch). Sprinkling had been considered suitable for 4 to 6 years after storm Vivian (1990), yet German observations showed first decay sporadically after the third year, Swiss sites after about 3 years, and a 25,000 m3 spruce pile in Vaud was dissolved just under 3 years after the storm; the worst case was onset after 2 years. It attacks almost only sapwood, so small logs lose most value.

For a yard: record the sprinkling start date, plan outflow inside the 2 to 3 year window where honey fungus was seen, and test permeability of long-stored wood before coating, because several months of storage can damage pit membranes and raise liquid uptake.

Putting it together: yard decision checklist

1. What is the felling date, species and sapwood share? Pine sapwood is notably blue-stain prone; opened beech oxidises in 1 to 2 days.
2. When will it be sawn? In warm weather plan for weeks, not months.
3. If longer, choose between debarked dry storage and sprinkling, and check the permit.
4. What is the output? Appearance products reject blue stain; structural products may tolerate it, but not early rot.
5. Write storage limits into the contract: felling date, sprinkling start, maximum storage time, blue stain and rot limits.

Limits of this course

This course was drafted by AI from the portal's fact-checked articles, not from standards or laboratory work. Figures come from specific studies in specific regions, which the lessons state. Several items were not verified by the portal, among them the class limits of EN 1927, EN 1316 and EN 1309-3, red heart frequency in beech, sprinkling temperatures and EN 350 class names. Always check figures against current standards, your contract and local permits before acting. This is not legal or contractual advice.

Key points

• Dry storage in bark is a few weeks only; debarked dry storage can last 1 to 3 years for spruce.
• Sprinkling needs permits and water; the 2025 Bavarian figures are 0.7 l/s per 1,000 Fm and 18 to 20 euro per Fm per year.
• Wet storage has a use-by date: honey fungus decay appeared after 2 to 3 years in some observations.
• Record felling date and sprinkling start for every lot.
• Check standards, contracts and permits; this course is AI-drafted and regional.