How Long Does a Bulk Bag of Logs Last?

If you’re planning your winter firewood supply, one of the most common questions is: How long does a bulk bag of logs last? The honest answer is that it varies — sometimes significantly. A bulk bag can last anywhere from a couple of weeks to several months, depending on how often you burn, what you burn on, and how efficiently your home retains heat.

This guide explains all the key factors so you can estimate your own usage accurately.

What Is a Bulk Bag of Logs?

Bulk bags (often called builders bags or tonne bags) typically come in three loose-fill volume sizes:

Common Bulk Bag Sizes (Loose-Fill Volumes)

These measurements refer to the approximate loose volume of logs poured into the bag, not stacked:

• 0.8m³ bulk bag – Ideal for occasional burners or topping up your store
• 1.2m³ bulk bag – A very common size for regular wood-burner users
• 1.6m³ bulk bag – Great for heavy winter users or those who want fewer deliveries

Because the logs are loose-filled, there are air gaps between pieces. This means a 1.2m³ loose-fill bag does not contain the same timber volume as a 1.2m³ stacked crate.

Bulk Bag vs Crate (Loose vs Stacked Volume)

• Bulk bags = loose-filled m³
• Crates = stacked m³, meaning logs are neatly packed together

A stacked cubic metre contains more wood than a loose-filled cubic metre, so crates typically represent better value per kWh of usable heat.

How Long Does a Bulk Bag of Logs Last?

The lifespan depends on four major factors:

1. How often you burn (every night vs occasionally)
2. Whether you use a log burner or open fire
3. The efficiency and age of your appliance
4. How well insulated your home is

Let’s break those down in detail so you can estimate realistically.

1. How Often You Use Your Stove or Open Fire

Frequency of use is the biggest determinant of how long your bulk bag will last.

Light / Occasional Use

• A few fires a week
• Short evening burns
• Mainly for ambience

A 1.2m³ bulk bag could last 6–10 weeks, sometimes longer.

Moderate / Regular Use

• Burning most evenings
• A mix of short and long burns

A 1.2m³ bulk bag may last around 4–6 weeks.

Heavy / Daily Winter Use

• Stove or open fire lit every night
• Long burn periods
• Main heating source

A 1.2m³ bulk bag might last 2–4 weeks, depending on your stove efficiency and insulation.

2. Stove vs Open Fire – Big Differences in Efficiency

Your appliance type is crucial because it directly affects how quickly you burn through logs.

Log Burner (Wood-Burning Stove)

• Typically 70–85% efficient
• Better control of airflow
• Retains and radiates heat long after flames die down
• Requires fewer logs for the same heat output

Result: A bulk bag lasts significantly longer in a stove.

Open Fire

• Typically 20–30% efficient
• Most heat lost up the chimney
• Needs frequent refuelling
• Pulls warm room air out of the house (negative pressure draw)

Result: A bulk bag can be used up twice as fast compared to a stove.

3. How Efficient and Modern Your Stove Is

Even among stoves, there are efficiency differences:

Ecodesign 2022 / modern stoves:

• Burn cleaner and hotter
• Extract more heat per log
• Reduce fuel consumption by 20–30%

Older stoves (Pre-2014):

• Poorer seals
• Less controlled combustion
• More wood needed for equal heat

If your appliance is older, expect shorter burn times and faster log consumption.

4. Home Insulation & Room Size

Your home’s ability to retain heat massively influences log usage.

Well-Insulated Homes

• Double/triple glazing
• Wall/loft insulation
• Draught proofing

Your stove won’t need to work as hard, so your bulk bag will last longer.

Poorly Insulated or Large Rooms

• Old single-glazed windows
• Loft/wall heat loss
• High ceilings
• Draughty spaces

Your fire must burn hotter and longer, so you’ll use your logs more quickly.

Typical Lifespan of Bulk Bag Sizes

These estimates assume kiln-dried hardwood logs, a modern stove, and regular evening use in an average UK home:

For heavy daily use, expect the lower end of each range. For occasional use, expect the higher end or beyond.

How to Make Your Bulk Bag Last Longer

Here are practical ways to extend burn time and get more heat per log:

✓ Use kiln-dried hardwood

Moisture content below 20% gives the best heat output and slowest burn.

✓ Keep your stove well-maintained

Clean flue, new rope seals, correct air settings.

✓ Use a stove thermometer

Stops you running the stove too hot.

✓ Improve insulation

Use curtains, draught excluders and plug heat-leaking gaps.

✓ Mix large and small logs

Start with smaller logs, then use larger pieces for sustained heat.

Is a Bulk Bag Enough for Winter?

For many UK households using a stove most evenings, a single 1.2m³ bulk bag often won’t last an entire winter.

Many regular burners use:

• 2–3 bulk bags per winter, or
• 1–2 large crates (stacked volume = more wood)

If you burn every day and use wood as a main heat source, you’ll likely need more.

Conclusion: How Long Does a Bulk Bag of Logs Last?

A bulk bag of logs can last anywhere from a couple of weeks to several months, depending on:

• Your burning frequency
• Whether you use a stove or open fire
• The efficiency of your appliance
• How well insulated your home is

As a rule of thumb:
A 1.2m³ bulk bag will last 4–6 weeks for the average UK household burning regularly.

If you want maximum value and longer burn times, consider kiln-dried logs, a modern efficient stove, and—where possible—upgrading insulation to retain more heat from each log.

Disclaimer: Usage Times Are Only a Guide

The information in this article is intended as a general guide. How long a bulk bag of logs lasts will vary significantly from one household to another, depending on factors such as appliance efficiency, type of fire (stove vs open fire), insulation levels, stove settings, the quality of the wood, and how often you burn. These estimates are not guarantees, and real-world usage can be higher or lower based on your specific circumstances. Always monitor your own burn rate to determine the most accurate replenishment cycle for your home.

Explore FirewoodFund’s Full Range of Kiln-Dried Logs

If you’re planning your firewood supply for the season ahead, exploring the right log size, volume and delivery option can make all the difference. FirewoodFund offers a full range of kiln-dried hardwood products, including bulk bags, stacked crates, small bags, kindling and natural firelighters—all delivered free across the UK mainland. Whether you burn occasionally or rely on your stove every night, you’ll find high-quality, Ready to Burn–certified logs to suit every home and every appliance. Browse the full range today and choose the perfect option for your needs.