The best expanding foams, compared.
Top pick: Soudal gun-grade gap filler, 12-pack Best value: Soudal Soudafoam Gap Filler – Best foam per pound among cans with several hundred reviews that reviewers say will dispense: 750 ml gun grade at about £7.19, 4.6 from 411. No gun in the box. Updated 22 October 2026.
Expanding foam is a one-component polyurethane aerosol for irregular gaps in masonry, timber and around pipes. It cures with moisture. On a UK job you choose a straw can for one hole or a gun-grade can when you will foam several openings. A sound can dispenses, aims and cures so you can trim it and paint it before sunlight breaks the bead down. The straw is a tube on the valve and is usually finished once foam sets in the nozzle. Fill about half the gap with a straw can, and about 60 to 70 percent with gun-grade foam, because it keeps expanding. Gun-grade foam is a threaded can and needs a gun and a cleaner you buy separately. How those two applicators differ is set out in the [expanding foam buying guide](/hub/fillers-adhesives-and-sprays/expanding-foam/sub/expanding-foam-buying-guide). High-expansion filler suits brick and can bow a uPVC or timber frame, so a window install is a different product. Ordinary foam is not fire stopping. Uncured foam contains isocyanates, so ventilate, wear gloves and eye protection, and keep the aerosol under 50 °C.
Expanding foam is a one-component polyurethane aerosol for irregular gaps in masonry, timber and around pipes. It cures with moisture.
42 products checked · 62 hrs invested · +24,100 readers
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Personal buying guide
Question 1 of 2
How many gaps are you filling?
The Soudal twelve-pack, part 116745_X12, is about £52.44 and rated 4.7 from 53 reviews, with 16 written texts. That 4.7 is the highest star line in the set, on the smallest count among the Soudal boxes. A bullet says 3.1 litres per can and a cut within 25 minutes. The printed dimensions, 32.8 × 6.6 × 6.6 cm, match the six-pack listing, while the weight is about 10.5 kg, so the dimension line may be copied. One reviewer said every can stopped the next day with foam still inside. Another said expansion was modest and still called the price good. A short review file and a case at about £52.44 do not outrank the single 750 ml gun can at about £7.19.
Pros
Cons
Best for: You already buy Soudal by the case and you accept a thin review file at this price.
Less suitable: You want the highest star line to mean a tested household winner, or you need one can for one gap.
Specifications
Common questions
How many reviews are on the listing?
4.7 out of 5 from 53 reviews. The saved listing has 16 written reviews.
What yield is printed?
A bullet says 3.1 litres per can, and cut within 25 minutes.
Did any review report cans dying overnight?
One reviewer said every can stopped the next day with foam still inside.
The Soudal VSA20AA box is twelve gun-grade 750 ml cans at about £47.99, rated 4.6 from 445 reviews, and the carton weighs 12.5 kg. A foam gun is not in the box, and this listing does not print a yield. Reviewers who already run a gun call it trade foam and good value when the cans empty properly, including one use for sound insulation. Other reviews describe poor propellant and little expansion compared with a similar brand, and one buyer bought a new gun and still blamed the batch. Delivery outside mainland UK is restricted on the listing. A case of twelve is a workshop quantity, and one skirting gap will not use it.
Pros
Cons
Best for: You already own a foam gun and a cleaner, and you will use a case of twelve cans.
Less suitable: You have one gap, you do not own a gun, or you need every can in the box to expand the same way.
Specifications
Common questions
Is a foam gun in the box?
The title is gun grade, 12 × 750 ml. A gun is not listed as included.
What is the pack weight?
The listing item weight is 12.5 kg. Package size is 29 × 26 × 22 cm.
Do reviewers report expansion problems?
Some reviews report poor propellant and little expansion. Others call the box good value when the cans dispense.
The Soudal Soudafoam Gap Filler, model 130585, is one 750 ml gun-grade can at about £7.19, rated 4.6 from 411 reviews. The listing says it is water resistant and heat resistant, with a full cure of one day. Reviewers who already own a gun prefer the control to a disposable straw, and they mention little splutter on high and low settings. The can does not include a gun, and the included-components line says n.a. Taking the gun off and putting it back on is where reviews report a leak. The compatible-material field says Foam, which does not tell you about brick or timber. At about £7.19 for 750 ml it is the best-value gun can in this set, and it does nothing on the day if you do not already have the gun and a cleaner.
Pros
Cons
Best for: You already own a foam gun and a cleaner, and you want one 750 ml can rather than a case.
Less suitable: You have no gun, you need a straw for a single hole today, or you are sealing a window frame with low-expansion foam.
Specifications
Common questions
Does this can include a gun?
No. Included components are listed as n.a. Reviewers use it with a gun they already own.
How long is the full cure?
The listing says full cure time 1 day.
Is it water resistant?
This listing says water resistant and heat resistant. Compatible material is given as Foam.
This Soudal gun-grade six-pack is about £28.99, rated 4.5 from 143 reviews, with 26 written texts. A bullet claims 3.1 litres per can and a cut within 25 minutes, and it says the foam is free of Freon, HCFC and CFC. The piece-count field says 1, which fights the six-pack title, and a gun is not in the title. Reviewers who already use gun foam praise the price once a metal gun is fitted. They also report guns that clog and stay clogged, weak expansion, and one can that split at the seam while it was shaken. Cleaner is what those reviews say keeps the gun usable afterwards. The 3.1 litre bullet is a listing claim, not a measured joint.
Pros
Cons
Best for: You already run a metal foam gun and you want a mid-size Soudal box rather than a single can.
Less suitable: You have no gun, you have no cleaner, or you are buying for one hole in a skirting board.
Specifications
Common questions
What yield does the listing claim?
A bullet says 3.1 litres per can. That figure is the listing text, not a measured joint volume.
When can you cut it?
A bullet says cut within 25 minutes.
What went wrong in reviews?
Reviews mention clogged guns, weak expansion, and one can that split at the seam while it was shaken.
This stone twin pack is two 500 ml cans at about £10.82, rated 4.4 from 3,768 reviews. Reviewers describe a straw nozzle that lays a bead around windows, doors and pipes, and one planter job was hard in about three hours, while another reviewer waited 24 hours before cutting. The title calls the foam outdoor and weatherproof. The brand attribute on the same listing says JKG Unknown, so the name in the title and the name in the attribute do not agree. Lids arrived damaged in some orders and would not close. It still drips, and masking is what keeps the foam in the gap rather than on the brick.
Pros
Cons
Best for: You want two weatherproof straw cans for more than one gap and you can live with a brand field that does not match the title.
Less suitable: You need a confirmed brand on the attribute line, a gun-grade can, or a lid you can trust to reseal.
Specifications
Common questions
What colour is this twin pack?
The listing colour is stone. Each can is stated as 500 ml.
Is it for outdoor gaps?
The listing says outdoor use and weatherproof. Reviews also report drips and a need to mask the area.
Who is the brand on the listing?
The title says Gorilla weatherproof expanding foam. The brand attribute on the same listing says JKG Unknown.
Ferris sells this as The Original Gorilla Filler: two cream 500 ml polyurethane cans at about £15.99, rated 4.4 from 652 reviews. The bullets say the cured foam can be cut, sawn, painted or sanded, and the water line says water resistant. The review text in this file is the same block as the Ferris single B0FQ615MWH, so those 652 reviews are not a second independent study. The complaints in that block are nozzles that arrived broken or blocked at once, tubes that fill so each can is one use, and propellant that runs out before the can is empty. Reviewers suggest a gun applicator, and this pack is still a straw filler. At about £15.99 it costs more than the stone twin at about £10.82 for the same stated 1,000 ml.
Pros
Cons
Best for: You specifically want the Ferris cream twin and you will check the nozzle before you rely on the second can.
Less suitable: You want an independent review file, a gun-grade can, or the cheaper 2 × 500 ml listing.
Specifications
Common questions
Is this the same as 151 Products Gorilla Filler?
The brand and manufacturer on this listing are Ferris, model Gorilla filler01. The title says Original Gorilla Filler.
Can you paint it?
The bullets say it can be cut, sawn, painted or sanded.
Are the 652 reviews only for this twin pack?
This file shares its review text and the 652-review line with the Ferris single can B0FQ615MWH.
The Ferris single is one cream 500 ml can at about £11.99, and it carries the same 4.4 from 652 reviews and the same review text as the Ferris twin B0CCDRWTWZ. The bullets say the cured foam can be cut, sawn, painted or sanded, and the listing says water resistant. The complaints in that shared block are a broken or instantly blocked nozzle, a one-use tube, and propellant that dies before the can is empty. Best Sellers Rank 4 matches the twin, so it may be a parent rank rather than this ASIN's own place. The listed weight is 540 g. You pay about £11.99 for one 500 ml can when the 151 Products Gorilla Filler single is about £6.75 on a review file of 7,701.
Pros
Cons
Best for: You want a single Ferris cream can and you will inspect the nozzle before you start.
Less suitable: You want a separate review study, or the straw can at about £6.75 with the larger file.
Specifications
Common questions
What is in the box?
One can. Included components say expanding foam filler. Pack count is 1 and unit count is 500 ml.
Can you paint it?
The bullets say it can be cut, sawn, painted or sanded.
Why does the review count match the twin pack?
This ASIN and B0CCDRWTWZ carry the same 4.4 from 652 reviews and the same review text.
The Soudal champagne twin is two 750 ml handheld cans at about £12.99, rated 4.4 from 156 reviews, with 19 written texts in the file. The title includes a nozzle and gloves, though the specification block does not repeat the gloves. The listing prints initial hardening at 25 minutes and a full cure of 24 hours. The water-resistance line says not water resistant, which sets this pair apart from the weatherproof straw cans. Surface recommendation includes pipe, window and wood, and there is no low-expansion figure. Reviews that give a defect mention a can that arrived broken and leaking, and one buyer who got only a small amount per press.
Pros
Cons
Best for: You want two straw cans with a printed cure time for a dry indoor gap, and you already know how foam behaves.
Less suitable: The gap gets wet, you need a large independent review file, or you are filling a window frame.
Specifications
Common questions
Does this twin pack include gloves?
The title says nozzle and gloves. The specification block does not repeat the gloves.
How long before it hardens?
The listing says initial hardening 25 minutes and full cure 24 hours.
Is it listed as water resistant?
The water-resistance attribute on this listing says not water resistant.
The Soudal combi box, part 152990, is titled as six 750 ml cans, one gun and one cleaner at about £47.25, rated 4.4 from 93 reviews. Reviewers who received that set describe a consistent bead and a gun you can adjust, which is the reason to buy a kit instead of a bare can. Other reviews say the gun was another brand, with Bondit named once, and that the cleaner was missing from at least one delivery. The item weight is printed as 550 g, which cannot be six 750 ml cans, and one bullet says Brand: Truly PVC. The carton is 40 × 40 × 30 cm on the listing. Treat it as a starter set only after you have checked that the gun and the cleaner are actually in the box.
Pros
Cons
Best for: You want cans and a gun in one order, and you will check the carton against the title before you rely on it.
Less suitable: You already own a gun, or you need the brand of the gun and the cleaner to match the title every time.
Specifications
Common questions
What does the title say is in the box?
Six 750 ml cans, one gun and one cleaner.
Is the gun always a Soudal gun?
Reviews say the gun was another brand, with Bondit named once, and that a cleaner was missing from at least one delivery.
Why is the listed weight odd?
Item weight is printed as 550 g, which does not match six 750 ml cans. The figure is stored as printed.
The Gorilla Filler GF2 from 151 Products is a 500 ml white straw can at about £6.75, and it sits at 4.3 from 7,701 amazon.co.uk reviews, the largest sample in this set. Reviewers use it around door frames and pipework, and one door-cavity review called it touch-dry within about an hour. The listing says it is waterproof and that the cured foam can be cut, sawn, painted and sanded. Reviews also say the nozzle will not fit a separate gun, and that the can is finished once you start because the tube blocks or leaks. Upward work drips, and several reviewers say gloves are essential because it sticks more than they expected. A manufacturer-part field that reads “LG Beauty LED Mask” is a broken attribute, not a foam specification.
Pros
Cons
Best for: You have one ordinary gap to finish today and you want the straw can with the largest review file in this set.
Less suitable: You already own a foam gun, you need a low-expansion frame foam, or you want to keep the rest of the can for next week.
Specifications
Common questions
Will this can fit a foam gun?
Reviews on this listing say it will not work with a separate applicator gun. It is sold as a filler can with its own nozzle.
Can you paint Gorilla Filler?
The listing says the cured foam can be cut, sawn, painted and sanded.
Can you save the can for later?
Reviewers describe it as a one-use can. The nozzle can block or leak once foam has set in the tube.
Gorilla Heavy Duty, model 115953, is a grey 353 ml polyurethane straw can at about £9.93, rated 4.2 from 490 reviews. It is not the 151 Products Gorilla Filler. The listing limits gaps and cracks to 2.5 cm, quotes tack-free in 8–12 minutes and a trim at 45 minutes, and says outdoor foam must be painted or coated because sunlight may discolour it. Reviewers say a smaller tin wastes less because a straw can is one use, and that a sparing bead is enough because it expands a lot. The nozzle does not stay fitted, and one review said one of two cans failed to discharge. The dimension field of 19.7 × 65 × 65 cm is not a plausible can size. At about £9.93 for 353 ml it is a dear small tin beside the 500 ml straw can at about £6.75.
Pros
Cons
Best for: You have one gap within 2.5 cm, you will use the whole small can today, and you will coat it if sunlight hits it.
Less suitable: You want the cheaper 500 ml Gorilla Filler, a gun, or a can whose nozzle stays on.
Specifications
Common questions
Is this the same as Gorilla Filler?
No. This is brand Gorilla, model 115953, 353 ml, grey. Gorilla Filler in this set is the 500 ml can from 151 Products.
Can you leave it outdoors unpainted?
The listing says outdoor use only if the cured foam is painted or coated, because sunlight may discolour it.
Do you have to use the whole can?
Reviewers say a straw can like this is one use once you start. The nozzle is also reported to come off.
Paint Factory Bond & Fill is a 500 ml can at about £5.82, the lowest shelf price in this set, rated 4.2 from 338 reviews. The title says quick setting. The specification block has no cure time and no yield, and hair-care attributes on the same page are junk, not foam data. Reviews that describe a successful fill say it sets hard. The failure pattern is the straw: a hole near the trigger, a valve that emptied the can into the tube, and a tube that leaked because it did not fit. Several buyers say it expanded less than they expected and tell others to buy Soudal instead. A price of about £5.82 does not help if the can never leaves the tube.
Pros
Cons
Best for: You are comparing the bottom of the price list and you will return a can that will not dispense.
Less suitable: You need the straw to work the first time, or you want a printed cure time before you cut.
Specifications
Common questions
How much foam is in the can?
The listing says 500 ml. It does not state a cured yield.
What do reviews say about the straw?
Reviews report a hole in the straw, a valve that emptied into the tube, and less expansion than expected.
Is a cure time printed?
No. The title says quick setting. The specification block has no cure time.
Twelve amazon.co.uk expanding foam listings were scored on a 0–100 scale. Amazon evidence is 30 points, from the star rating, with a deduction when the count is small, when the written set is thin, or when two ASINs share one review block. Listing fit is 35 points. A straw can with a stated volume, a clear water line, and a job it can finish today scores for a one-off gap. A gun-grade can scores when the listing is honest that the gun is extra. Contradictory brand, weight, piece-count, or water lines are deducted. Review outcome is 20 points. Reviews that describe a filled gap score higher than a blocked straw, a can that will not empty, or a kit whose gun and cleaner do not match the title. Value is 15 points, from the shelf price in GBP against a can a review says will dispense. The lowest price does not score when the straw fails. A 12-can case does not score as a household bargain. The highest score is the top pick. The best foam per pound among cans with several hundred reviews that reviewers say will dispense, after the missing gun is already noted, is the best value. A published free-foam figure is not used as the volume of a finished joint. Prices are the amazon.co.uk shelf prices on 19 October 2026. This is not a laboratory test.
Amazon evidence
30%Star rating on amazon.co.uk, then a deduction when the count is small, when the written set is thin, or when two ASINs share one review block.
Listing fit
35%A straw can with a stated volume, a clear water line, and a job it can finish today scores for a one-off gap. A gun-grade can scores when the listing is honest that the gun is extra. Contradictory brand, weight, piece-count, or water lines are deducted.
Review outcome
20%Reviews that describe a filled gap score higher than a blocked straw, a can that will not empty, or a kit whose gun and cleaner do not match the title.
Value
15%Shelf price in GBP against a can a review says will dispense. The lowest price does not score when the straw fails. A 12-can case does not score as a household bargain.
Match the applicator to the number of gaps, then check expansion, the volume you will actually use, and the clock printed on that can. A free-foam litre claim is not the volume of a finished joint, and ordinary foam is not a fire seal.
Expanding foam here is a one-component polyurethane aerosol for irregular gaps in masonry, timber and around pipes. It cures with moisture. A straw can is for one job. A gun-grade can is for repeat work, and it does nothing until you own a gun and a cleaner. A sound can dispenses, aims and cures so you can trim and paint it before sunlight breaks it down. A window frame or a fire seal needs a product that is not this type of can.
Straw foam should fill about half the gap, and gun-grade foam about 60 to 70 percent. The rest is post-expansion. A full hole bows a frame and spills.
None of these titles say low-expansion. High-expansion filler suits brick and can bow a uPVC or timber frame. Soudal's Window & Door foam is a different product.
A 28 litre free-foam figure and a 3.1 litre Amazon bullet are not the same measure, and neither is the volume of a finished joint. A straw can is usually finished once the tube fills.
A straw can needs no gun and is usually finished once the tube fills. Gorilla Filler reviewers say that straw can does not fit a gun. Gun-grade foam needs a gun and a cleaner, and the listing should say so. In this set the single 750 ml gun can, the 6-pack and both 12-packs leave the gun out. The combi box puts a gun and a cleaner in the title, and reviews dispute the gun brand and a missing cleaner. Straw foam has higher post-expansion: fill about half the gap.
High-expansion gap filler suits brick. It can bow a uPVC or timber frame. None of these titles say low-expansion, so they are the wrong can for a window install. A 500 ml straw can is the one-hole buy. The 353 ml listing prints tack-free in 8 to 12 minutes and trim in 45 minutes. The champagne twin prints 25 minutes to initial hardening and 24 hours to full cure, and it is listed as not water resistant. The 750 ml gun can prints a one-day full cure.
Three typical situations, each with a recommendation from this comparison.
You have one ordinary gap to finish today and you want a straw can with a large amazon.co.uk review file. Gorilla Filler is the top pick: 500 ml at about £6.75, 4.3 from 7,701 reviews, listed as waterproof and paintable. It is a one-use tube and it will not fit a gun.
You already own a foam gun and a cleaner, and you want one gun-grade can rather than a case. The Soudal 750 ml can is the best value at about £7.19, 4.6 from 411 reviews, water resistant, with a full cure of one day. No gun is in the box.
You already run a gun and you will use twelve cans. The Soudal VSA20AA box is about £47.99, 4.6 from 445 reviews, about £4 a can on this snapshot. The gun is not included. Do not fill a fire-resisting gap with these cans, and read the diisocyanate label if you use foam at work.
The top pick is Gorilla Filler at about £6.75: a 500 ml white straw can, 4.3 from 7,701 amazon.co.uk reviews, listed as waterproof, and the cured foam can be cut, sanded and painted. Reviewers fill gaps around door frames and pipework. It is a one-use tube, and it will not fit a gun. The best value is the Soudal 750 ml gun-grade can at about £7.19, 4.6 from 411 reviews, listed as water resistant, with a full cure of one day. No gun is in the box, and reviews report a leak if you remove the gun and refit it. The can at about £5.82 is not best value when reviewers say the straw will not dispense. A 4.7 from 53 reviews is not the household winner.
Soudal Soudafoam Gap Filler
Best foam per pound among cans with several hundred reviews that reviewers say will dispense: 750 ml gun grade at about £7.19, 4.6 from 411. No gun in the box.
Editorial
Peter F. is the editor for DIY & tools at productscompared.co.uk. Comparisons in this category are checked against amazon.co.uk listings, review evidence and public UK sources.
Guides on what to look for, how to use a product, and common mistakes.
Public UK sources used for this comparison. amazon.co.uk prices, stars and review counts were taken from the listings on 19 October 2026.
Expert source (DIY & tools): Charlie White (Charlie DIYte) (external profile) – public expert commentary used as a research source, not as a contributor to our pages.
This page contains affiliate links to amazon.co.uk (tag pcuk26-21). If you buy through them, we may earn a commission at no extra cost to you. Prices, stars and review counts are from the listings. This is not a laboratory test.
