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Best expanding foam in this set, with a condition

Updated: 23 October 2026

Best expanding foam only means something once you say what the gap is and whether you already own a gun. On the [expanding foam comparison](/hub/fillers-adhesives-and-sprays/expanding-foam), the straw pick for one ordinary gap is Gorilla Filler 500 ml. The gun pick is the single Soudal 750 ml, and only if the gun and a cleaner are already on the bench. Prices are the 19 October 2026 shelf figures. A qualifying amazon.co.uk purchase can earn a commission at no extra cost to you. If you do not own a gun, stop at the straw pick. The longer order is the [expanding foam filler buying guide](/hub/fillers-adhesives-and-sprays/expanding-foam/sub/expanding-foam-buying-guide).

Best expanding foam only means something once you say what the gap is and whether you already own a gun.

Our top picks

Soudal Soudal Soudafoam Gap Filler 750 ml

Best overall

Soudal Soudal Soudafoam Gap Filler 750 ml
8.7/10about £7.19
View offer
Gorilla Filler Gorilla Filler stone, 2 × 500 ml

Rank 2

Gorilla Filler Gorilla Filler stone, 2 × 500 ml
8.3/10about £10.82
View offer
Gorilla Filler Gorilla Filler 500 ml

Rank 3

Gorilla Filler Gorilla Filler 500 ml
9.2/10about £6.75
View offer
On this page
  1. 1.Best straw can for one gap
  2. 2.Best gun can if you already have the gun
  3. 3.The cheapest can is not the value pick
  4. 4.Kits, and the other Gorilla names

Best straw can for one gap

Gorilla Filler, model GF2, is a white 500 ml straw can at £6.75, 4.3 from 7,701 reviews, the largest file in this set. The bullets say it is waterproof, and that cured foam can be cut, sanded and painted. Reviewers describe door frames and pipework. One door-cavity review called it touch-dry within about an hour. That is one job, not a cure time for every can. The nozzle will not fit a gun. Once you press the trigger the tube blocks or leaks. Upward work drips. The manufacturer-part field reads LG Beauty LED Mask, a broken attribute. Skip it for a low-expansion uPVC foam, a tested fire seal, or a can you can pause. The stone twin at £10.82 is the same straw style, with a brand attribute of JKG Unknown. Ferris cans at £11.99 and £15.99 share one review block.

Best gun can if you already have the gun

Soudal Soudafoam Gap Filler, model 130585, is one 750 ml gun-grade can at £7.19, 4.6 from 411 reviews. The listing says water resistant and heat resistant, with a full cure of one day. Reviewers who already own a gun describe better control than a straw. It is the best-value gun can here because the gun is not in the box. Soudal’s UK page quotes about 28 litres of free foam, a fill of about 65 per cent, and +5 °C to +30 °C. Free foam is open-air output, not 28 litres of hole, and this listing does not print that figure. Reviews report a leak if you take the gun off and refit it. If you foam every week, the VSA20AA box is 12 × 750 ml at £47.99, 4.6 from 445, about £4 a can on this snapshot. The £52.44 twelve-pack is 4.7 from only 53 reviews. The arithmetic is on gun foam vs straw foam.
Soudal Soudal Soudafoam Gap Filler 750 ml

Testsieger

Soudal Soudal Soudafoam Gap Filler 750 ml
8.7/10about £7.19
View offer

The cheapest can is not the value pick

The lowest price is Paint Factory Bond & Fill, 500 ml at £5.82, 4.2 from 338 reviews. The title says quick setting. The specification block does not. Reviews describe a hole in the delivery straw, a valve that emptied the can into the tube, and expansion that fell short. A bargain that stays in the tube is not the best-value can. The value pick is the £7.19 gun can for someone who can already use it.

Kits, and the other Gorilla names

The combi box at £47.25 is titled as six 750 ml cans, a gun and a cleaner. Reviews say the gun was sometimes another brand, with Bondit named once, and that a cleaner was missing from at least one delivery. The weight field says 550 g, which cannot be six 750 ml cans. Gorilla Heavy Duty, 353 ml at £9.93, is tack-free in 8 to 12 minutes, trims in 45 minutes, and states gaps up to 2.5 cm. The nozzle comes off in reviews, and the price per millilitre is higher than the 500 ml straw can. No can here is the best foam for windows. These ASINs are Gap Filler. Soudal Window & Door is not in the table. Stars measure whether people were broadly content, not whether the second squeeze will still flow.

Common questions

What is the best expanding foam for a single DIY gap?
In this set it is the 151 Products Gorilla Filler 500 ml at £6.75, 4.3 from 7,701 reviews, if the gap is an ordinary hole you will finish today. It is a straw can. It will not fit a gun, and you should not keep it for next weekend.
What is the best value if I already own a gun?
The single Soudal 750 ml gun-grade can at £7.19, 4.6 from 411 reviews. You still need cleaner, and reviews mention a leak if you take the gun off and put it back on. A twelve-can box is cheaper per can only when you will use the case.
Is the cheapest can the best value?
No. Paint Factory at £5.82 has the dispensing failures: a holed straw, a valve emptying into the tube, and weak expansion. Price is the wrong first sort when the can may not leave the nozzle.
Is a 12-pack better because the star rating is higher?
The £52.44 twelve-pack is 4.7 from 53 reviews. The £47.99 twelve-pack is 4.6 from 445, with propellant complaints in the file. A higher star line on a small sample is not a reason to store 10 kg of foam for one gap.
Which Gorilla can is the pick?
The white 500 ml Gorilla Filler from 151 Products. The grey Gorilla Heavy Duty 353 ml is a different can, dearer per millilitre, with a loose nozzle in reviews. The Ferris cream cans reuse the Gorilla Filler name and share one review block between the single and the twin.
Is any can in this set the best foam for windows?
No. These are gap-filler cans. Soudal Window & Door is a different product and it is not one of these ASINs. A surface field that says window is not a low-expansion claim.

Related pages

How to use expanding foam

Expanding foam around windows

Expanding foam

Expanding foam filler guide: straw, gun or neither

Gun foam vs straw foam: when the extra kit is worth it

Sources

Public UK sources used for this comparison. amazon.co.uk prices, stars and review counts were taken from the listings on 19 October 2026.

  1. HSE isocyanates (retrieved 19 October 2026)
  2. Retained Regulation (EU) 2020/1149 (retrieved 19 October 2026)
  3. HSENI diisocyanates (retrieved 19 October 2026)
  4. Fire safety: Approved Document B (retrieved 19 October 2026)
  5. Hertfordshire Building Control PU-foam note (retrieved 19 October 2026)
  6. Soudal Soudafoam Gun Gap Filler (retrieved 19 October 2026)
  7. Soudal Soudafoam range (retrieved 19 October 2026)
  8. Penosil UK straw foams and gun foams (retrieved 19 October 2026)
  9. Polycell Expanding Foam (retrieved 19 October 2026)