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Best lava rocks for a gas fire pit

Updated: 21 October 2026

You want one bag for a gas fire table, and the results mix a 4.5 from more than two thousand reviews with a £7.62 box and two tumbled bags at the same shelf price. Best lava rocks for a gas fire pit, in this four-ASIN set, means the tumbled size that matches a shallow burner, not the longest star line. The full table stays on the [lava rocks comparison](/hub/outdoor-fire-pits/lava-rocks). Peter F. checked those listings on 20 October 2026. There was no lab burn. A qualifying purchase can earn a commission at no extra cost to you. The figures compared here are £7.62, £15.99 and £19.50. A search that day already showed higher shelf prices, so treat today’s price as movable.

You want one bag for a gas fire table, and the results mix a 4.5 from more than two thousand reviews with a £7.62 box and two tumbled bags at the same shelf price.

Our top picks

Black Rock Grill Black Rock Grill 4 kg, 4–8 cm

Best overall

Black Rock Grill Black Rock Grill 4 kg, 4–8 cm
9.4/10about £19.50
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SOUJOY SOUJOY 1–2 in, 10 lb

Rank 2

SOUJOY SOUJOY 1–2 in, 10 lb
9.4/10about £15.99
View offer
SOUJOY SOUJOY 2–3 in, 10 lb

Best value

SOUJOY SOUJOY 2–3 in, 10 lb
8.6/10about £15.99
View offer
On this page
  1. 1.Top pick for a gas fire table
  2. 2.Best value, and the cheap skip
  3. 3.The barbecue bag and the coarser pebble
  4. 4.What this set does not include

Top pick for a gas fire table

The top pick is the SOUJOY 1–2 in bag, B0CPHRX7ZJ: black tumbled lava, titled 10 lb, package line 4.48 kg, at £15.99, about £3.57 per kilogram. It is 4.5 from 164 reviews, rank 40 in Outdoor Fire Pits. UK reviews praise coverage and heat. One bag measured about 40×40 cm, and two bags were slightly too much for a small square table. Buy a second only if it will not cover the pilot. Skip it for a 2–3 in fill or fine catering chips. Non-UK notes on soot and a stone leaving a bowl are not a UK rate. Size and weight are on the lava rocks buying guide.

Best value, and the cheap skip

Best value is the same 1–2 in bag, not the cheapest box. HENDI is 3 kg of fine lava, model 152706, at £7.62, about £2.54 per kilogram, 4.0 from 818 reviews. UK reviews say much of the box is ordinary stone, and that dust around 2 cm falls through a grate. The listing prints no centimetre size. Tumbled bags here are about £3.52 to £3.57 per kilogram. Black Rock Grill is about £4.88 per kilogram. Brightstar lists 5 kg at £14.40, one shop, and not one of these ASINs. One HENDI review describes a rock exploding after about 20 minutes and causing burns. That is one report, not a rate. If the title is tempered glass, use lava rocks vs fire glass.
Black Rock Grill Black Rock Grill 4 kg, 4–8 cm

Testsieger

Black Rock Grill Black Rock Grill 4 kg, 4–8 cm
9.4/10about £19.50
View offer

The barbecue bag and the coarser pebble

Black Rock Grill, B00ECXW86A, is 4 kg of unfinished brown lava at 4–8 cm, from Turkey, at £19.50. It is 4.5 from 2,160 reviews, rank 23 in Barbecuing Charcoal. Reviewers cite heat under a grill tray, and they break large pieces for a shallow tray. A 24 kg bullet disagrees with the 4 kg line. Pond buyers sit in the same star file, and the listing does not show the rock is safe for fish. The SOUJOY 2–3 in bag, B0DQ7WXW65, is the coarser tumbled stone at the same £15.99, 4.54 kg, 4.1 from 41 reviews, rank 69, with four UK notes. Choose it only when the manual wants a chunk larger than 1–2 in. Weber UK forbids lava rock in a Weber gas grill, so none of these bags is a Weber refill.

What this set does not include

Brightstar’s £14.40 bag is a specialist 5 kg layer outside this ASIN table. A Teamson Home title shown around £10, sometimes with an 800°C line, is not a test of these four bags, and tempered fire glass in that title means glass. Take the 1–2 in bag as top pick and best value when the manual allows that size. Take Black Rock Grill for a lava-bed barbecue if you can live with 4–8 cm. Take the 2–3 in bag only for a coarser pit. Leave HENDI unless you will sort ordinary stone off a fine grate.

Common questions

Which bag in this set is the top pick for a gas fire table?
The SOUJOY 1–2 in bag, B0CPHRX7ZJ, at the comparison price of £15.99. It is 4.5 from 164 amazon.co.uk reviews and rank 40 in Outdoor Fire Pits, with a package line of 4.48 kg. One review covered about 40×40 cm. Skip it for a 2–3 in fill, fine catering chips, or a Weber grill. Weber forbids lava rock in its gas grills.
Is the cheapest bag the best value?
No. HENDI at £7.62 is about £2.54 per kilogram, the lowest sticker here, and 4.0 from 818 reviews. UK reviews say much of the box is ordinary stone and that dust falls through a grate. Best value in this set is the 1–2 in tumbled bag at about £3.57 per kilogram, because those notes do not describe the contents as ordinary stone.
Why is a 4.5 from 2,160 reviews not automatically the fire-pit pick?
Black Rock Grill’s sample is large and the 4.5 is real, but rank 23 is in Barbecuing Charcoal and the star file includes pond and plant buyers. Pieces at 4–8 cm are the wrong shape for many shallow tables, and a bullet says 24 kg against a 4 kg weight line. The fire-table pick is the 1–2 in bag at rank 40, because the job matches. Stars alone are not a burn test.
When is the 2–3 in SOUJOY the better tumbled bag?
When the manual asks for a coarser surface than 1–2 in and you accept 4.1 from 41 reviews, with only four UK reviews in the notes. The price is the same £15.99, the item weight is 4.54 kg, and the rank is 69 in Outdoor Fire Pits. On a small table the 1–2 in size already has the clearer UK notes.
What is wrong with using HENDI on a wide grate?
UK reviews put pieces around 2 cm and say dust falls through. A wide barbecue grate, or a fire pit where fines can enter the jets, loses the refill and can block ports. The listing states the box for gas barbecues and prints no centimetre range. Several reviewers also say a large share is ordinary stone. One explosion report is a single review, not a rate.

Related pages

Lava rocks for a gas barbecue

Lava rocks

Lava rocks buying guide: piece size and bag weight

How to use lava rocks in a gas fire pit, dry first

Lava rocks vs fire glass: which media for a gas pit

Sources

Public UK sources from the research digest, plus the amazon.co.uk listing facts in the display file. Shelf prices and star lines are those stored UK figures. No bag here is treated as certified or laboratory tested.

  1. GOV.UK: smoke control areas, the rules (retrieved 21 October 2026)
  2. GOV.UK: garden bonfires, the rules (retrieved 21 October 2026)
  3. GOV.UK: smoke control enforcement in England (retrieved 21 October 2026)
  4. Defra: reducing air pollution from outdoor burning (retrieved 21 October 2026)
  5. Gas Safe Register: barbecue safety (retrieved 21 October 2026)
  6. Brightstar Fires: 5 kg lava rock (retrieved 21 October 2026)
  7. Mid and West Wales Fire and Rescue: firepit safety (retrieved 21 October 2026)
  8. Calor technical note: LPG barbecues, EN 498, outdoor only (retrieved 21 October 2026)
  9. Weber: lava rocks or ceramic briquettes in a Weber gas grill (retrieved 21 October 2026)