# Shed insulation - was my leg being pulled?



## Escudo (1 Apr 2008)

What ho shipmates,

Found myself mooching around this big garden centre and wandered to the outbuilding department where I was looking at the various sheds, garden offices etc.

Salesman turned up, so out of interest I asked what the sheds were insulated with?...He said "Bubblewrap sandwiched between aluminium foil"

and went on to say - "it is the same stuff they use in formula 1 cars and came from space shuttle technology"

Cool or what? 8)


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## wizer (1 Apr 2008)

Double Bubble Foil and Trouble

http://www.just-insulation.com/ufoil.html


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## TheTiddles (1 Apr 2008)

ermmm, same principle perhaps... but there the similarity ends. Multi-layer super-insulators are employed in racing cars, space craft etc... but you won't find the same stuff in your shed! 

Aidan


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## Escudo (1 Apr 2008)

Thanks Wizz, that looks quite good, light and easy to install, also designed for timber buildings. I wonder if any other forum members have used this material?


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## Fecn (1 Apr 2008)

I've been warned off multifoil insulation by other forum members. Apparently it doesn't do anything like as well in tests as the manufacturers claim. There's some more info in one of RogerS's threads... http://ukworkshop.co.uk/forums/viewtopi ... insulation


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## Escudo (1 Apr 2008)

Fecn, cheers for that link, interesting development in this discussion.

Perhaps that stuff is not all it is cracked up to be after all.

The outbuildings I was looking at seemed very well made, although they were also very expensive.

20 x 12 building in Western Red Cedar, with shingle roof cost £15,130 thats excluding groundworks, electrics or coloured exterior finish.

Extra windows £360 each and guttering at £10 a foot.

I wonder what the raw material cost of a building that size would be?

Cheers, Tony.


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## Smudger (1 Apr 2008)

I've used it in my shed. It seems to work pretty well, the max/min says that the lowest temperature this winter was 0℃, when outside temperatures were down to about -4.


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## tnimble (2 Apr 2008)

At least for spacecraft a similar product is used. Altough it doesnot consist of bubblewrap and alufoil. The stuff used consists of various layers foil of carbon fibree, glass fibre, zilver, and aluminium alloy. Its higly heat resistant and reflect almost 100% of the heat and radiation protecting the craft.

The products on the market for building insulation does work but not entrely as state. A shed heatsup or cools down through 3 processes; transport through flow (convection), radiation and conductance. Traditional insulation materials only work to reduce the amount of convected heat loos / warm up. This material only reducted loss and warmup by radation.

Surfaces that are in contact of each other have high conductive properties. In a building with doudle walls there is not that many of contact area. Most heat is transferred through air flow and radiation.

The heat conductivness of non moving air is very low. Traditional isolation traps as many air in small pockets. The air ceases to move and no heat is transfereed by convection (transported by air flow)

Heat is only transferred by radiation between to surfaces that have some distance between them and are in line of sight. (heat radiation is infra red light, some things are transparent for infra red light that are not for visible light and vice versa)

For a double wall without insulation in between the sun heats up the outside wall through radiation. The outside wall heats up the inside wall through radiation. Through convection and a little conduction the room heats up. The same stands for the heating in the winter. The warm inside heats up the inside wall which radiates its warmth to the outside wall....

When a double wall is fully stuffed with insulation the entire wall construction is heated up by the sun's radiation. The wall again heats up the room by mostly convection. Because of the insulation material the room heat up is delayed but not prevented. (in the winter again all the same but in reverse). Traditional insulation that has a layer of alu foil does not add much to the insulation it's main purpose is a moister barrier.

When you place a reflector in between the wall and the sun the heat up is stopped. The same when a reflector is placed in the middle of a double wall without insulation. But this radiation is only reflected if there is radiation. There has to be free space between the reflector and the walls. About near to 1" at both sides. For the insulation to work the insulation takes up about 2 1/4 " of room. Traditionsal insulation of the same thickness gives about as much amount of insulation some materials such as polyisocyanurate gives more.

When only using the multifoil there is still alot of heat loow in the winter heat up in the summer. The convection has not been stopped. Heat is still transferred through air flow. When not combining the reflector with traditional insulation you don't have the claimed high insulation.

To have these high insulation figures for both winter and summer you need the inside wall/ceiling, an free space of near 1", the foil, a free space of near 1", about 3" of traditional insulation, a near 1" free space, the foil, a near 1" free space, the outside wall/roof


Hope this helps


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## Woody Alan (2 Apr 2008)

Tony
I agree that the bubble wrap is over rated, I think sound insulation is a very important factor. The hard packed rockwool slabs from places like Wickes will do a superior job in both sound and insulation. Insulation board in 8x4 sheets from "seconds and co" is excellent insulation, but I am not sure if it's sound insulating properties are as good as it is a relatively hard material. If you are doing the insulating yourself I would recommend the rockwool as the other board is awkward and has to be cut accurately to fix in place and the dust is horrible makes you itch like crazy and you really don't want to breath it.

Cheers Alan


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## YorkieT (3 Apr 2008)

My workshop ( a ex BT site cabin ) dripped with condensation from the fibreglass type roof but since I lined it with the aluminium / bubble wrap insulation it has been converted in to a warm / dry space overnight  

I have also installed a 180w tube type heater for the really cold nights which comes on via a timer and it holds it's heat very well, I hope it also reflects the sun in the summer as it used to be like a sauna in the summer months :shock: I might install a air conditioning unit this summer if things don't improve 8)


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## radicalwood (4 Apr 2008)

Hi Guys,

I have one of these peoples timber double garages (warwick buildings) as a workshop its 18' x 18'
cost erected is about £4000 see link below and the foundations cost about £1200.
been using it for 7 years still looks like new  .

www.warwickbuildings.co.uk

cheers
Neil


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## ratkinsonuk (10 Apr 2008)

I built a 22x12 shop myself - http://s51.photobucket.com/albums/f355/ ... mview=link - and raw costs were about £4000

I certainly wouldn't pay 15k for a timber building like this. It's possible to buy a similar sized workshop to mine for a similar price, but building it yourself has a number of advantages :-

1) It's bespoke to your needs
2) Usually better materials
3) Good learning excercise
4) Hopefully enjoyable
5) Low risk of 'Cowboy' work

Rob.


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## severus (12 Apr 2008)

I have to agree with ratkinsonuk its far better to build your shed/workshop yourself. I recently constructed a 16' x 11' shed complete with steel profile roof lined and insulated for about £1600 including the concrete base.

The insulation I used was fibre glass cavity bats


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## ike (12 Apr 2008)

I think 100mm fibreglass wool is really good value for money and gives a excellent level of insulation for a shed.


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## beech1948 (12 Apr 2008)

severus,

I would be really interested to know about your workshop as I am starting to build one to replace my old barn shop which is cold, drafty and sometimes difficult due to close contact with neibours on that side.

I am curious about which/whose steel roof panels you used.
What did you use to insulate or were they already insulated
How big is your workshop

regards

Alan


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