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Insulating external wall using... wait for it...

Discussion in 'Building' started by treefella, 19 Jan 2012.

  1. treefella

    treefella

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    Aluminized mylar space blankets.
    Mylar sheet installed internally with an aluminized coating on the side facing you.
    Possibly 1200 grade lining paper first(or god forbid polystyrene) and finished
    with 1200 paper. (Really do not fancy any polystyrene. Too easily damaged.)

    Anyone ever tried it? Copyright < me 2012 ;)

    What you think?
     
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  3. fmck

    fmck

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    I opened up a mates one while climbing in the dolomites to shelter from the rain under only to find the foil had decomposed/fallen off the sheet. It had been in the bottom of his rucksack for sometime so we reckon these emergency blankets are not made to last. Glad we found out the easy way although when the lightning started we packed it away as there was still enough foil there to cook us :D
    Maybe it might work but for a building I would be looking for something more substantial
     
  4. treefella

    treefella

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    With a decent adhesive, and lining paper over the top. I cannot see it rotting away. Sandwiched between adhesive it has no where to go.
    All it has to do is reflect the heat back.
     
  5. mointainwalker

    mointainwalker

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    So what insulation value are you expecting from this ?


    You are correct though about PS being easily damaged when used for this.
     
  6. treefella

    treefella

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    That's something I have no knowledge about, sorry.

    It's in a stairwell which is always very cold, especialy now winter is here.

    I will be using a water resistant adhesive, no idea which one at the moment.
    And then sealing it with the same, then hanging the lining paper over the top as normal.

    Not going to decorate for a few months to see if there are any side effects.


    The mylar emergency sheets are 1.5m x 2.1m supposedly they reflect up to 97% of radiated heat. I figure any % they reflect is heat recovered.
    http://en.wikipedia.org/wiki/Space_blanket

    The main issue I worry about is that they could act as a heatsink, drawing more heat away. I guess I'm going to find out.

    It's a really cheap project, worse ways I batten/insulate and board afterwards if the results are bad.

    20pc 1.5m x 2.1m works out at £12 inc. p&p. + cost of adhesive.
    Area to cover is approx. 7m x 4m so 28sq.m
    Works out cheap as chips, litteraly.

    I am going to go ahead with it (unless I find a major floor in the idea)and will update my results.
     
  7. freddiemercurystwin

    freddiemercurystwin

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    We'll look out for your next thread in the DIY Disasters section! :mrgreen:
     
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  8. mointainwalker

    mointainwalker

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    Ordinary aluminium-foil - and I don't think Mylar will be any better - is reckoned to have an R value of about 0.2. This is worth having but is so small that you won't notice it.

    Since it's a stair-well, i'd say batten the walls, put polystyrene between the battens and finish with plasterboard.

    Don't forget though that insulation doesn't create heat. If the stairwell is unheated, then the small amount that leaks in from surrounding heated spaces will still leak out - albeit more slowly - even when insulated.
     
  9. ^woody^

    ^woody^

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    Foil as an insulator will be good for radiant heat, OK for convected heat but crap for conducted heat ..... which is the type of heat passing through a material such as floor/walls/ceilings

    So it will be OK for behind the radiators to reflect some heat back into the room, but once the heat is in the structure it will be not so useful to retain it

    The risk of interstitial condensation will also be increased
     
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  11. AronSearle

    AronSearle

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    Multifoil insulation without the multifoil or insulation :LOL:

    For it to reflect heat, it would need an airspace in front of it, and if you have an airspace, then you may as well insulate that space, which will work better than a single sheet of reflective material.
     
  12. Deluks

    Deluks

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    I remember reading something about these, something like 10% of TOTAL heat loss is via radiated heat, so you will save roughly 10% of the heat you are losing now. Fairly pointless IMO, even 25mm of polystyrene should beat that.
     
  13. treefella

    treefella

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    In the back of my mind was the thought that for it to be of any use it might need to have air or a cavity behind it.
    I figure if I vent behind the cavity, that should remove any chance of condensation build up.


    If they can place that foam stuff on a wall then I think that there would be a DIY way of achieving the same goal, only not having to pay the crazy price per roll that they do for their products.

    As I said, worse ways I have to do it the 'old fashioned' way.

    Thanks for the information, that will help me not ending up in the disaster zone haha.

    Edit.
    Seems that what I was thinking of is called a radiant barrier. And besides being not much use in cold climates, there's also the possibility of incorrect installation being fire hazard. Don't do this at home kids.

    http://www.energysavers.gov/your_home/insulation_airsealing/index.cfm/mytopic=11680

    So that idea's out the window. Saved myself nearly £20 not bodging this on me walls.

    Foam or battens or exterior insulation/rendered over, seems the only proper solution for solid walls.
     
  14. Deluks

    Deluks

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    Smart move. Battens and a pack of 50mm rockwool won't break the bank, neither will poly backed plasterboard.
     
  15. treefella

    treefella

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  16. mointainwalker

    mointainwalker

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    treefella

    You seem to be a seeker after the magic easy solution - are you in your 20's or 30's and easily convinced/suckered ?

    Insulation that works will sell itself by telling you its insulation value which is expressed either as U or R and you can calculate how much it costs to save a given amount of energy.

    Other products that are aimed at the gullible have lots of diagrams and much talk of " saving 70% ..." or "reducing by 80% ..." (without ever explaining 80% of what) but no U or R values , and by EMPHASISING HOW EASY THEY ARE TO INSTALL.

    If it hasn't sunk in, then I have a very large bridge to sell - only one careful owner - and I'm sure it would dramatically enhance your life and well-being.

    P.S. Very easy to install :mrgreen:
     
  17. jeds

    jeds

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    There's no magic bullet - it's all been tried before. Aluminium foil is common - on the back of foil backed plasterboard. Yes there's a small gain in emissivity but it's negligable in the scheme of things. Fact is you won't do better than a layer of Kingspan (ok, aerogel will do better but can you afford the mortgage?) I also don't rate Multi layer foils because I've never seen anyone fit them properly. They are only effective if the foil is suspended with the correct cavity gaps both sides and that never happens in real life. OK in a nice test lab where they obviously make sure everything is perfect but try telling the grunge monster that on site.
     
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