Thin mineral wool or glass wool with aluminium layer for cavity wall

[Clennls]

Hi all,

 

I am looking to decide which insulation I want to use for our cavity wall. We want to use either mineral wool or glass wool. However, the insulation that comes with an aluminum layer for reflective heating and windproofing is quite expensive. We have found the insulation Petralight 20 cm, which is affordable and has good density, but we can't find a thin insulation with an aluminum layer. They all seem to be at least 130 mm or so. We can install 240 mm of insulation.

Are there any brands with thin insulation that has an aluminium layer or are there very damp-open PUR, PIR insulations on the market?

 

Otherwise we have found a very damp-open aluminium cover for insulation but are not sure how to attach it. We could only use the insulation plug's but i am not sure if the foil will not tear arround the plugs. Otherwise we would need to install some wood in between the insulation, but that is also a lot more expensive, and we would lose some insulation vallue. There are some wool insulations on the market which have a white glass fiber layer on them, but I can't find if these are any good for reflective insulation.

 

Thanks in advance

[Russell griffiths]

What do you think the aluminium layer will do inside a cavity. 
i personally can’t see it being of any help at all. 
if this is a new build i would ask some more questions on here and look at all the options for your insulation. 

[JohnMo]

Bit lost what are you trying to do with the aluminium? Not sure what damp has to do with a cavity wall?

[saveasteading]

52 minutes ago, Russell griffiths said:

aluminium layer will do inside a cavity. 

It reflects energy. It doesn't have to be visible to us for the shinyness to continue.

But it needs an air gap...or it is pointless.

 

It doesn't follow that I think this is necessary of a good choice here.

@Clennls what is driving you in this direction? There are perfectly well proven mainstream products.

[Russell griffiths]

1 minute ago, saveasteading said:

It reflects energy. It doesn't have to be visible to us for the shinyness to continue.

But it needs an air gap...or it is pointless.

 

It doesn't follow that I think this is necessary of a good choice here.

@Clennls what is driving you in this direction? There are perfectly well proven mainstream products.

How does the energy get through 100mm of brickwork, the cavity on the outside of the insulation is generally cold. 
still baffled. 😂

[Nickfromwales]

Are we really looking at a cavity insulation layer of 240mm and then your air gap, or is that the actual depth of the cavity which means you cannot fully fill it?

 

I’d pump this full of blown, bonded EPS beads, as with that product you can fully fill the entire cavity without issues of cold / damp / moisture bridging.

 

Quick and simple to do in a day, depending on the qty / area obviously. 

[SteamyTea]

1 hour ago, Russell griffiths said:

How does the energy get through 100mm of brickwork

Same way it passes through everything, including a perfect vacuum.

By photon/electron/phonon exchange.