Non-motoring > Insulation - polystyrene v rockwool Miscellaneous
Thread Author: Dave Replies: 19

 Insulation - polystyrene v rockwool - Dave
I need to insulate my workshop. I believe that rockwool is better for a given thickness, but thickness is not a problem for me. Polystyrene sheets are much cheaper than rockwool and a lot lighter. So what are the advantages of rockwool and polystyrene?
 Insulation - polystyrene v rockwool - Fullchat
Will rockwool absorb moisture? I recently saw one of those cowboy builders programmes where work had been done and rockwool used to insulate the cavities instead of fiberglass. The Building Control dept. made them remove it. Caused an inordinate amount of work and expense.
 Insulation - polystyrene v rockwool - Tooslow
Dave,
you said "workshop" so maybe the fact that you can get sheets of polystyrene is useful to you? A dab of glue on each corner, offer up to shed wall and there you are. Whereas rockwool comes in rolls or slabs so will be more difficult to fix in place(?).

I don't know how the insulation values compare but if you poke around sites like tinyurl.com/33zhhg6 you should get some idea of how they compare.

JH
 Insulation - polystyrene v rockwool - Netsur
polystyrene is flammable and carcinegeous (?) when burnt. Anything that is made from glass fibre is not flammable and therefore safe.

 Insulation - polystyrene v rockwool - MD
Glassfibre wool is NOT safe. Don't ask me the technicalities, but it isn't. I won't work with it. Itchy coo being the least of your worries.

My Dad used to say, "shiver faster Boy, you'll soon get warm".

MD
 Insulation - polystyrene v rockwool - FotheringtonTomas
I'd go for polystyrene. Easier to fix. No fibres and shards of fibre floating about to be breathed in and make you itch. Doesn't sop up water. Stays put. I'd board it over, though, after sealing the edges. Note, if you run PVC insulated cable through it it will deplasticise the PVC, which will become stiff/brittle.
 Insulation - polystyrene v rockwool - teabelly
Neither. Get the space blanket stuff in rolls. No itching, no issue with flammable material either.
 Insulation - polystyrene v rockwool - MrTee43
Kingspan.
 Insulation - polystyrene v rockwool - Dog
How abowt this ~ tinyurl.com/3432gum
 Insulation - polystyrene v rockwool - L'escargot
Here's what Rockwool say about their products. www.rockwool.co.uk/product+guide
 Insulation - polystyrene v rockwool - Dave
Thanks guys. I weld in the workshop, and even though it's only TIG so not many sparks, I will need to line it out. Guess I need to go down the DIY place and price it all up.
 Insulation - polystyrene v rockwool - Mapmaker
Polystyrene is highly flammable.

Along with polyester carpets, and synthetic curtains and synthetic fibres in chairs I won't have it anywhere near my house.


Ah, but my sofa is "Flame retardant" you say; yes, that means that you have thirty seconds after dropping a fag on it to get out of the building. Drop your fag on a wool carpet/sofa, and it might smoulder a bit before it goes out.
 Insulation - polystyrene v rockwool - FotheringtonTomas
>> Polystyrene is highly flammable.

No it isn't, but it will burn. That's a good reason for boarding it over. Plasterboard is cheap.
 Insulation - polystyrene v rockwool - VxFan
Hasn't this Polystyrene insulation got a layer of aluminum foil over it? The stuff Tommy Walsh and other TV DIY'ers use has. Surely the aluminum foil will reduce any risk of fire or at least delay it.
Last edited by: VxFan on Mon 10 May 10 at 19:14
 Insulation - polystyrene v rockwool - Tooslow
I think that's Kingspan as suggested above. Ace stuff.

JH
 Insulation - polystyrene v rockwool - car4play
As others have said if you want the best insulation go with Celutex (or Kingspan). Both are the same kind of stuff. It comes in 8x4 sheets of differing thicknesses.
It's the stuff used by builders for new cavity walls, loft conversions, underfloor insulation etc. because it has a fantastic insulation rating (much better than rock wool, fibreglass, etc. ) and you can board over the top of it by screwing straight through plasterboard and it.

I insulated the whole of our downstairs with 80mm Kingspan as the base for underfloor heating. The dust from cutting it isn't very pleasant but it's no way as bad as fibreglass.

If you don't need pucker quality but want to save some money then you might like to try some of the outlets that sell seconds. I'll find the site I used when back at my computer tomorrow and edit this post then.
 Insulation - polystyrene v rockwool - car4play
>> If you don't need pucker quality but want to save some money then you might
>> like to try some of the outlets that sell seconds. I'll find the site I
>> used when back at my computer tomorrow and edit this post then.

The place I used is here:

www.secondsandco.co.uk/
 Insulation - polystyrene v rockwool - MD
Polywhatsnot gives off Cyanide of some sort when burnt.

AVOID.
 Insulation - polystyrene v rockwool - Victorbox
I work in the property insurance industry and the mention of polystyrene as an insulation material causes an underwriter heart failure! Kingspan (as the market leader) LPC approved Polyisocyanurate (PIR) insulation panels are the way forward.
 Insulation - polystyrene v rockwool - rtj70
Rockwool (name of the company and product) is used for both sound insulation and a fire barrier. I believe it's made from volcanic rock. I know of a company specialising in it's use for this making custom solutions for industrial customers and building projects.
Last edited by: rtj70 on Thu 13 May 10 at 12:04
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