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Soudal Genius Gun Gap Filling Expanding Foam 500ml

4.7 (461 reviews)
SKU: 240301125826007 EAN: 5411183112575
Seal and insulate large holes, gaps and joints with this clever expanding foam that will grow to up to 35 times its original volume. Thanks to the genius gun applicator, you can accurately operate this cartridge with one hand. It keeps out sound and heat, so use it to seal around pipes, windows and doors and to help with sound proofing.\nThis product is very stable once it''s set, so it won''t shrink or continue to expand. It''s HCFC and CFC free, meaning it''s kind to the o-zone layer. The product is extremely quick drying (roughly half an hour), and once it''s cured, you can cut it, sand it, plaster or paint over it.\n\n• All purpose, fast curing expanding foam filler\n• Single handed operation\n• Genius gun applicator - accurate, easy to control and easy to use\n• Adheres to all common building materials\n• Can be cut, sanded, plastered or painted after full cure\n• Up to 35 times original volume\n• Shrinkage after curing: < 3%\n• Expansion after curing: < 1%\n• Expansion during curing: 117%\n• Temperature resistance: -40°C to +90°C (cured) and to +120°C for up to one hour\n• Approx. ½ hour cure time\n• Reusable for up to 6 weeks once opened\n• Interior and exterior use
Brand Soudal
Type Expanding Foam
Volume 500 ml
No features listed
No items listed

Customer Reviews 461

4.7
461 reviews
5 star
369
4 star
70
3 star
12
2 star
5
1 star
5
Idwisott*
4.0
March 1, 2026
Percy Parts Verified Purchase

Job done - reasonable price.

Now then - any more holes....?

*IT DID WHAT IT SAID ON THE TIN

Works well
5.0
February 25, 2026
DavidB_DIY Verified Purchase

Good performance and works well in a number of DIY situations

Gap Filler
5.0
February 25, 2026
DIYer Robert Verified Purchase

I always find Soudal products reliable and good value and this was no exception

Good Product- work v well.
5.0
February 21, 2026
f166c966-9435-5983-ae97-6e764de95794 Verified Purchase

Worked very well. Only grumble us that the stopper couldn’t be removed the next day and had to be cut off to allow further use. Otherwise strong stuff which does exactly what it’s designed to very well.

Great product
5.0
February 18, 2026
ZA110 Verified Purchase

Easy to use, great quality. Has a lot of use. Purchased 2 but ended up only using 1

foam filler
5.0
February 15, 2026
Weeble1955 Verified Purchase

The Foam Filler was brilliant easy to use. Dried in a few hours ready for plastering.

Shop staff Meh
1.0
February 7, 2026
Exasperated21

Staff in the shop don't seem to know what they are picking. Supplied a completey different product which resulted in a half hour trip back to shop to see dumb and dumber. PRODUCT REVIEW -The correct replacement is pretty good stuff

Gap filler.
2.0
January 28, 2026
abatt Verified Purchase

doesn't flow that easy, takes a lot of time drying and to messy to work with. Price is OK OK for small jobs

Expanding Foam
5.0
January 24, 2026
Trevorxxxx Verified Purchase

Works as expected filled the gaps around pipe work

Gap filler
5.0
January 21, 2026
Clive E Verified Purchase

All good filled a hole around new flue outlet worked well.

Expands faster than my waist at Xmas
4.0
January 21, 2026
bf78656b-5c95-551e-bb78-c7b479c1d053 Verified Purchase

easy to use, easy to store, does what you want. Unlike the foam there is nothing else I can "expand" on

Works just as expected.
5.0
January 19, 2026
c53796ab-1333-569b-a88a-e6f8a514c22d Verified Purchase

Works just as expected. A little messier than others I have used. It's not smooth out of the can, but otherwise it works fine and sets in pretty good time.

Good gap filler
4.0
January 12, 2026
BSaurus Verified Purchase

Only used a small amount as it really does expand a lot. Filled the gap, left 24 hours, cut back excess ready for fine finishing. Easy enough even for me. Used the supplied gloves as it is messy.

Controlled, Clean, and Effective
5.0
December 19, 2025
mattk78 Verified Purchase

Soudal Genius Gun Gap Filling Expanding Foam 500ml delivers controlled application, strong expansion, and reliable insulation. Easy to use with its Genius Gun applicator, it fills gaps cleanly, cures quickly, and can be cut, sanded, or painted for a neat finish. A great choice for DIY and light trade sealing jobs.

Do not use in the cold
3.0
December 11, 2025
GPNotADoctor Verified Purchase

Applied this in a massive hole in the wall when it was probably about 8 degrees outside. It didn't seem to have expanded much so I ended up putting more in. Only then did it start to work. After 5 hours it was still expanding and ended up coming through the vent, so now I have to use the Soudal foam remover. Not happy as it's a nightmare to clean up.

Great product
5.0
December 7, 2025
63f26c70-c6f2-53ab-a389-0ff4a889225c Verified Purchase

Does what it sez on the tin, works great everything you need included like cloves tap off screw worked a treat.

If you're using it all in one go, then great, otherwise don't expect it to work next time!
3.0
December 4, 2025
PMC247 Verified Purchase

Whwn it works, it's a nice foam with medium-slow expansion which gives you time to dispense just the right amount into the gap. Spraying the gap lightly with water works well to help expansion.

I had a can of this from about 4 months ago that sat in the garage about 80% full; there is a "bung" supplied to put in the end of the dispenser tube after use, but only after purging out the tube by using the can wrong-way to blow out the excess foam in the tube. Mine was unsuable despite doing all this.

So another can it is then, this time the smaller size so less wastage. Same problem though - when I try to purge the tube wrong-way up (yes I know you're meant to dispense the foam with the can upside down, but you purge the tube with the can upright i.e. wrong-way). I still get foam being dispensed! Eventually, it goes runny but still fills the tube. A week later, I pulled the bung out, detached the tube and pulled out the remaining foam. So upside down, it should work right? Nope, just like the other can I had it is blocked - not in the tube, but in the actuator pin in the top of the can. So honestly, I can only recommed it for one-time use.

Nice small can
5.0
November 25, 2025
Trisstan Verified Purchase

Good product. Nice small can to get into small awkward spaces

Excellent Product & Price
5.0
November 25, 2025
SW Jones Verified Purchase

Did the job perfectly and able to re use a couple of weeks later.
Handy size, more than enough than I needed and not having to go to the expense to buy a larger one.
Would recommend, easy to use.

Good product
4.0
November 23, 2025
GLHM Verified Purchase

Used to fill a hole that a mouse was coming in for the in-laws. Worked great, very easy to use. Can't complain.

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