Burning dried peat leaves moderate ash, about 5-15% of the fuel’s weight according to the parent article, which comes to roughly 0.1-0.8 tonnes a year for a household using 5,000-8,000 blocks. The ash is mildly alkaline and can be used sparingly on acid soil, but it stays hot for hours and must never be dumped on a bog or dry heath, where it can start an underground fire.
Part of Peat Harvesting
What peat leaves behind when it burns: the quantity of ash, how it differs by bog, what it is good for and how to dispose of it safely.
How Much Ash
The parent gives peat ash as 5-15% by weight and mildly alkaline, useful as a soil amendment or for soap. Ash depends on the peat: peat from rain-fed bogs carries less mineral matter than fen peat, and blocks cut near the clay or gravel base pick up more.
Worked estimate. Inputs: dried block mass 0.43-0.64 kg at 30% moisture (derived in BTU Content Compared to Wood, from an assumed bog density); 5,000-8,000 blocks a year; ash 5-15% of the dried mass.
- Dried fuel = 5,000 × 0.43 = 2,150 kg (2.1 t) to 8,000 × 0.64 = 5,120 kg (5.1 t).
- Ash = 2.1 t × 0.05 = 0.11 t to 5.1 t × 0.15 = 0.77 t.
So expect between about 0.1 and 0.8 tonne of ash a year. The wide range is the parent’s 5-15% multiplied through; weigh your own.
Uses
- Soil. Wood and plant ash raise soil pH much as lime does, so over-application is a risk (Wood Ash). Spread thinly, test the soil pH if you can, and do not use it on crops that need acid soil.
- Lye and soap. The parent says peat ash can be used for soap. Its potash content is unmeasured here, so test a batch before relying on it (Wood Ash Lye).
Method: Handling Ash Safely
Step 1: Let the stove cool before removing ash, or lift it with a shovel into a metal bucket.
Step 2: Keep it in metal, away from walls, thatch and stacks, for at least a day after removal.
Step 3: Check before disposing. Stir with a stick; any warmth or glow means it is not out.
Step 4: Spread cold ash on cultivated ground, not on bog or heath.
Common Mistakes
- Tipping ash on the peat stack’s edge. Hot ash ignites it.
- Putting wet, cold ash in a wooden box. Embers can survive inside.
- Over-liming a garden. Ash raises pH.
Safety
Peat ash holds heat, and peat burns underground
Ash from peat can stay hot for a long time. A smouldering peat fire spreads through the ground itself, burns below the surface for weeks or months, and can re-ignite the vegetation above it. People have stepped onto ground with fire beneath it. Never discard ash on a bog or dry peaty ground, and keep clear of any ground that smokes.
What’s Next
- Learn next: Stove Compatibility — ash pans and grates
- Combine with: Wood Ash — soil use of ash