solid wall insulation idea

[robbob]

I have been trying to work out how to insulate our solid walls.  it seems tricky (or expensive) from reading the forum and my builder is telling me it will have little impact. My question is whether you could insulate a solid wall using woodfibre board covered by wood panelling?  This would be much cheaper than plastering over with lime plaster. i am sure it can not be that easy so if someone could explain gently why this wouldnt work!  many thanks

[A.L.]

hello and welcome robbob,

With woodfibre insulation you are going to need an effective vapour check on the warm side of the insulation to prevent interstitial condensation at the insulation/stone interface. Or choose an insulation with its own inbuilt vapour resistance. e.g. extruded polystyrene

A 50mm layer of extruded polystyrene will reduce heat loss through a 30cm sandstone wall by typically 75%

[Ted]

Ty Mawr  do some specialist woodfibre insulation boards designed for solid walls - although it is best not to check the prices unless you have just won the lottery.

[biff]

then there is the 8 ft x 4 ft sheets of foil backed plasterboard which comes with kingspan pink or blue attached,to denote the thermal quality.
 a special adhesitive is used to stick the sheets directly directly to the wall in question and then the recessed,,or tapered joints are taped and skimmed.
      if you have any doubt of how good this is,just take a north facing wall which gets little or no sunshine and do the wall with this combination, you will notice immediatly that the room gets warmer with each sheet you fix to the wall.
                                                                                                biff

[JohnH]

Hi Robbob
I put a similar request to the forum back in July. Someone suggested Gyroc Thermaline Plus which has a minimum thickness of 27mm. This seems a very good idea so I am going to opt for this type of insulation because
it doesn't take up too much space on internal walls. It's available on Ebay.

http://www.british-gypsum.com/products/plasterboard___accessories/gyproc_thermal/gyproc_thermaline_plus.aspx

JohnH

[robbob]

thanks, really helpful all.  i had got myself into a muddle thinking that there very much shouldnt be a vapour barrier to allow vapour through the whole wall so that has saved me a mistake! our walls are 60cm stone/rubble/stone but it sounds like it is still worth doing if i get anywhere close to a 75% saving. just off to toss a coin between the Gyroc and Kingspan, Ted is right about the cost of the Ty Mawr product!

RB

[billi]

sad really  i find , that good proved eco insulation boards like the wood fibre boards  are offered  so expensive  in the UK

Sometimes it seems that  some suppliers add on an extra profit  cause its new and ECO   to a country

I find these wood fibre boards  quite  affordable  in Germany


Has anybody any figures how energy intense these  oil based insulation boards from say Kingspan  are ?

Billi

[Ivan]

I spoke to someone last week, who is planning to start manufacturing low-cost Struturally-insulated panels in the UK (not much good for the original poster, but nevertheless a good move to bring down the cost of specialist insulation panels. He's hoping to expand into other areas of insulation later).

Does anyone know where I can find an online calculator which allows you to work out the heatlosses from walls of different thicknesses and with different layers of materials?