Can i use Polystrene Packaging as insulation

Plasterer

1984ReturnsForReal wrote: »

Some of the products under the polystyrene commercial banner gives off cyanide when burnt.

Do you really want it in your house?

Not rockwool - it doesnt burn

cyclonebri1

Plasterer wrote: »

Not rockwool - it doesnt burn

Not all rockwool is suited to use in cavity wall insulation, it has to be the cavity wall batt type, not the stuff on a roll which will transmit moisture and effectively bridge the cavity.
The cavity closer I have used on occaision is actually polystyrene wraped in the same material used for the damp proof course This has a flap of material that is pinned behind the frame fixings to retain it in place,

If you have opened up the doorway you may have removed some cavity ties or brick work that was acting as a tie. Check there are sufficient ties at each side of the frame and if there aren't strapp accross at 2 or 3 points to hold the whole lot together. (cut down wall plate/roof straps are ideal).

vaio

Plasterer wrote: »

Don't think so Vaio, hes taken a door frame out and replacing it with plasterboard - rest of the house has 2 skins of brick with a cavity in between then either wet rendered or dot and dabbed then skimmed. The apature he is closing of will have just board in front of it?!? if he pushs rockwall in ( 3 -4 foot if he wants! then boards it, it will take it back to how the house would have origionally have been with regards to insulation. Sorry I didn't read in his thread that he had problems with insulation anywhere else in the house?

Ahh, they way I read it was he was taking out the old front door & frame because the house now has a porch.

So the bit of wall in question used to be an external one but is now effectively an internal one so little point in insulating that bit.

As he didn’t mention existing cavity insulation and was complaining about drafts from the cavity I assumed no cavity insulation hence my suggestion to just close the cavity and get the whole house done

cyclonebri1

Yep, more info required for a definitive, (collective), view

1984ReturnsForReal_2

Plasterer wrote: »

Not rockwool - it doesnt burn

I did say "some".

Unfortunately it seems the OP doesn't know what the supply he has actually is..

I think it is best to assume the worst in this case.

The stuff manufactured for modern day home insulation would indeed not give off cyanide when burnt.

budgetdiyer

Thanks for the replies guy.

Viao and Plasterer, deading your descriptions i'd say you are both right, i'll try and explain the scenario again, which might hopefully be a little clearer.

The original front door to my house was on the side of my house, at some stage the previous owners have built a porch which has doors to the front garden and then one to the back garden and then the original front door into the house.

To free up some space i've removed the original front door and now have to tidy around the opening, i'd don't have any particular problems with insulation and draughts etc, but with the current weather conditions you can definately feel colder air coming through the cavity.

What i really want to know is do i just seal the cavity with expanding foam and then board / plaster over for decorative purposes, or is it worth stuffing some insulation into the cavity before boarding over.

Since the area i'd be able to stuff with insulation is now effectively and internal wall i don't need to worry about insulation breaching the cavity, all the wall ties are present and intact in the cavity and naturally the door opening has a lintel so no structural issues here, naturally a UPVC door does hold any load!

vaio

That's what I thought, all you need to do is close the cavity and decorate.

No point in insulation as it is now effectively an internal wall but a lot of point in getting the whole house cavity insulated whilst it’s still grant aided (which it might not be for much longer depending on who get elected)

cyclonebri1

In that case fit building polystyrene using a non solvent mastic adhesive, then plasterboard over the lot, it will support the plasterer board better than softer insulation lessening the risk of cracking.