# Adhesive for polystyrene sheets



## doorframe (7 Dec 2011)

I need to fix 25mm polystyrene sheets to the inside of a metal shed.

Basically, these....







to the inside of one of these




.

Last time I tried to stick polystyrene it melted! Anyone got any ideas??

TIA

Roy


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## xy mosian (7 Dec 2011)

Try to track down some water based contact adhesive, or perhaps Copydex?

xy


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## geertswaans (7 Dec 2011)

i always used grab fil to glue those sheets to access hatches. 
always worked fine. 
or try that waterproof stuff from unibond
G


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## twothumbs (7 Dec 2011)

There used to be a specific poly adhesive ..thick and gungy. Phone a manufacturer.


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## chrismyerz (7 Dec 2011)

I have just done the same to my metal shed... 25mm EPS sheets on the ceiling as was getting fed up of being soaked when ever any thing touched it!

I used instant grab adhesive from wickes, solvent free version and had no probs at all

Cheers
Chris


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## flanajb (8 Dec 2011)

You just need to make sure what ever adhesive you use does not contain styrene.


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## Harbo (8 Dec 2011)

And don't spill diesel on them!!

Rod


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## JakeS (8 Dec 2011)

flanajb":1lo5pcu6 said:


> You just need to make sure what ever adhesive you use does not contain styrene.



Or acetone, or xylene, or any one of many other solvents which styrene will dissolve in. And that it doesn't get hot while it cures, because polystyrene melts at fairly low temperatures and IIRC gives off toxic fumes.



To be honest, if I were in the same situation and I had some to hand, I'd probably try one of the various no-more-nails-a-likes on a scrap of the insulation board, leave it to dry to see if it damaged it - I'd expect it to be absolutely fine. As a last resort, you'd probably have success with heavy-duty double-sided tape, but it's probably an expensive way to do it.

I seem to recall polystyrene breaks down under UV, and can crumble away after a couple of years if it's not covered, so it's probably worth putting boards or paint over it once it's hung. (If you do paint it, again, be careful which paint you use - water-based is generally best.)

I'm possibly over-thinking it, but if you're planning to attach some kind of hard surface to the inside after the insulation anyway, could you not just sandwich the polystyrene in and fasten those mechanically? Attach battens to the wall, stuff the insulation between the battens and then screw boards to the battens over the top, or something? Whatever adhesive you use, the polystyrene will break well before the glue fails - I don't know what the standard practice is, but I wouldn't trust it to hang boards on or anything myself...


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## doorframe (8 Dec 2011)

Cheers All. Screwfix do a few solvent free grab adhesives for around a pound and a half. 



JakeS":3uyc4b3f said:


> I seem to recall polystyrene breaks down under UV, and can crumble away after a couple of years if it's not covered, so it's probably worth putting boards or paint over it once it's hung. (If you do paint it, again, be careful which paint you use - water-based is generally best.)
> 
> I'm possibly over-thinking it, but if you're planning to attach some kind of hard surface to the inside after the insulation anyway, could you not just sandwich the polystyrene in and fasten those mechanically? Attach battens to the wall, stuff the insulation between the battens and then screw boards to the battens over the top, or something? Whatever adhesive you use, the polystyrene will break well before the glue fails - I don't know what the standard practice is, but I wouldn't trust it to hang boards on or anything myself...



I'm already fully battened, about 12" spaced in the smaller profiles, giving me about 25mm cavity. This is filled with rockwool and sheeted over with 6mm packing ply. Trouble is that the screws (25mm drywall screws) are conducting the cold from the batten through to the screwhead which then forms a drop of condensation as the cold screwhead meets the warmer air inside. If I kept the interior cold I wouldn't get the problem. 

I want to fill the cavities with poly and then another layer over that, giving me 50mm, but then I need to fix more (25mm) battens vertically and poly between them (giving me 75mm) so I can then T&G clad. I don't want to fix through to the original battens as I'll just draw more cold spots through, so I need to find a way of fixing the battens strong enough to hold a fair weight of timber cladding.

Does that make sense?? :? 

Roy


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## Lowlife (8 Dec 2011)

PU expanding foam works perfectly, we do a lot of polysculpture at work and use it to assemble components, or to glue foam blocks together to make bigger ones, and of course it fills gaps too.


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## Mark A (8 Dec 2011)

Harbo":1g75icnn said:


> don't spill diesel on them!!


 OR petrol because it makes napalm!! :shock:


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