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Bulk bag buying guide: read the label, not the title

Updated: 23 October 2026

You have an empty builders' bag in an amazon.co.uk basket, and the title says tonne or heavy duty. Those words do not state the safe working load, the safety factor, the loops, or how many bags are in the pack. This bulk bag buying guide is the order of checks for the six empty FIBCs on the [bulk bag comparison](/hub/diy-supplies/bulk-bag). The prices below are the shelf prices saved from those listings, in pounds. A qualifying purchase can earn us a commission at no extra cost to you. The editorial team read the listings against a Construction Plant-hire Association site note. This is not a lab fill, and it is not a live price check on 22 October 2026.

You have an empty builders' bag in an amazon.co.uk basket, and the title says tonne or heavy duty. Those words do not state the safe working load, the safety factor, the loops, or how many bags are in the pack.

Our top picks

A&A SUPPLIES UK A&A Supplies UK 1 tonne builders bag, 85 cm

Best overall

A&A SUPPLIES UK A&A Supplies UK 1 tonne builders bag, 85 cm
8.6/10about £8.79
View offer
DIVCHI DIVCHI 1 tonne builders bags, pack of 10

Best value

DIVCHI DIVCHI 1 tonne builders bags, pack of 10
8.2/10about £30.49
View offer
A&A SUPPLIES UK A&A Supplies UK 1 tonne FIBC, 90 cm

Alternative

A&A SUPPLIES UK A&A Supplies UK 1 tonne FIBC, 90 cm
7.3/10about £8.71
View offer
On this page
  1. 1.What the title does not tell you
  2. 2.SWL, then the safety factor
  3. 3.Loops and the pack count
  4. 4.An empty sack, not delivered stone
  5. 5.Stop at the four label lines

What the title does not tell you

Tonne bag on these pages means the seller is pointing at a builders' bag. It does not mean a merchant is delivering a tonne of gravel. All six listings are empty woven sacks. An £8 or £9 single is a different purchase from a delivered bag of stone, and from a trade sack that another site starts at about £1.40 excluding VAT. Heavy duty is the same kind of phrase. CPA TIN 026, dated 30 January 2023, tables single-trip at 5:1, standard-duty reusable at 6:1 and heavy-duty reusable at 8:1. None of these six prints 6:1 or 8:1. That table is a site note, not a certificate for any ASIN here.

SWL, then the safety factor

Read the safe working load first. In this set that line is 1,000 kg, or 500 kg on the green half-tonne bag. Five-to-one does not mean you may load five tonnes. It is the single-trip class: one fill up to the printed SWL, not permission to reuse the bag all summer. If the factor is missing, you do not invent it from a sister listing of the same brand. Three listings print 5:1: the A&A 90 cm single at £8.71, the half-tonne at £8.99, and AirTech-UK at £15.98. Three do not: the A&A 85 cm single at £8.79, and the DIVCHI packs at £22.00 and £30.49. Same brand is not the same label. DIVCHI's 2,200 lb line is about 998 kg, the same claim as one tonne. Size is a separate choice, on the one tonne versus half tonne page.
A&A SUPPLIES UK A&A Supplies UK 1 tonne builders bag, 85 cm

Testsieger

A&A SUPPLIES UK A&A Supplies UK 1 tonne builders bag, 85 cm
8.6/10about £8.79
View offer

Loops and the pack count

A lift uses the loops the bag actually has. Airtech names four reinforced 30 cm side-seam loops. The 85 cm A&A and the half-tonne name four sturdy lifting loops. DIVCHI says corner lifting loops and does not print a count. The 90 cm A&A does not number the loops at all. If the listing is blank, you count what arrives. You do not copy four from a different ASIN. Airtech's title says two bags and the unit-count line says 3.0. UK reviews say the photo looks like three and two arrive. Price a bag from the line you used, not from an average of two and three. The DIVCHI packs share one 4.7-from-954 line. Do not add those two 954s.

An empty sack, not delivered stone

Once those four lines are readable, the figure on the page is a shelf price for an empty sack. None of these listings is a bag of aggregate dropped on the drive. If you need stone, sand or topsoil brought to the house, you are buying a delivered load. Stars come after the label. The 85 cm A&A is 4.7 from 1,542 reviews and still has no safety factor. The 90 cm A&A prints 5:1 and sits at 4.4 from 182. A higher star line does not print a missing factor, and it does not settle a two-versus-3.0 pack.

Stop at the four label lines

If you only needed the checklist, stop at the safe working load, the safety factor, the loops and the pack count. Leave the title words where they belong. Do not invent a missing line from a sister bag. The stars are the last line you read, not the first.

Common questions

What is the difference between SWL and the safety factor?
The safe working load is the mass the listing says the bag may hold: 1,000 kg, or 500 kg on the half-tonne. The safety factor, when it is printed, says which duty class that load sits in. CPA TIN 026 tables 5:1 as single-trip, 6:1 as standard-duty reusable and 8:1 as heavy-duty reusable. A factor without an SWL, or an SWL without a factor, is an incomplete label. None of these six prints 6:1 or 8:1.
Why do some bags in the same brand print 5:1 and others do not?
A&A prints 5:1 on the 90 cm single and on the half-tonne, and does not print it on the 85 cm single. The brand line is shared. The label line is not. DIVCHI prints no safety factor on either pack. Copy the factor only from the ASIN you are buying. A sister page does not fill a blank.
How many loops should the listing name?
Use a count when the page gives one. Airtech says four 30 cm side-seam loops. Two A&A bags say four. DIVCHI says corner loops and stops. The 90 cm A&A does not number them. Four is usual on a builders' bag, and it is still a blank until this listing prints it. Count the loops on the bag that arrives before you hang it on a machine.
What if the photo shows more bags than the title?
Keep the conflict in view. Airtech's title says two, the unit-count line says 3.0, and reviews say the picture looks like three while two arrive. Say which line you used if you work out a price per bag. Do not average two and three into a quiet unit price.
Is an empty £9 bag the same purchase as a delivered bag of stone?
No. The singles here are about £8.71 to £8.99 for an empty sack. A delivered bag of stone, sand or topsoil is the material plus haulage. Trade empty bags from about £1.40 excluding VAT are another channel again. Compare empty with empty, and filled deliveries with filled deliveries.
Which line tells me the bag is single-trip?
The safety factor, when it is printed as 5:1. That is the single-trip class in CPA TIN 026. A title that says heavy duty does not say it. A multi-use bullet without 6:1 or 8:1 does not move the bag into a reusable class. If 5:1 is missing, the listing has not told you the class.

Related pages

Best builders bulk bag

How to fill and lift a bulk bag

Bulk bag

Bulk bag for garden waste: leaves, soil and the tip

1 tonne bag vs half tonne bag: same price, different size

Sources

Public UK sources from the research digest, plus the amazon.co.uk listings compared on this page. Shelf figures are saved captures, not a live check on 22 October 2026.

  1. CPA TIN 026 Issue B (30 January 2023) (retrieved 22.10.2026)
  2. HSE lifting equipment (retrieved 22.10.2026)
  3. GOV.UK, DIY waste charges scrapped (retrieved 22.10.2026)
  4. GOV.UK consultation outcome on DIY waste (retrieved 22.10.2026)
  5. BSFL Packaging, builder bag sizes (retrieved 22.10.2026)
  6. FIBCA UV white paper (retrieved 22.10.2026)
  7. The Bulk Bag Store, one-tonne FIBC (retrieved 22.10.2026)