# Forum Home Renovation The Garden Shed  Shed roof insulation help needed

## Jim Ferrous

Hi, my tool shed is 12' x 10' and has a flat tin roof with a gentle slope. The roof has finally rusted out after 40 years and I'm planning on re-roofing it next weekend. I would like to put some insulation under the new tin as when the sun is beating down on it, the heat radiated down can be pretty intense. The way the shed was built there is only 3 beams holding the roof up so I will need to put chicken wire up to stop the insulation from sagging over time. 
Ideally I would have liked to have used vapor-chek but because of the way the shed is built, I wouldnt be able to seal all the edges and I think I would have a problem with glass fibres. So I will most likely just use sarking. Will sarking make much of a difference in stopping the heat being radiated downwards? If I put two layers up, does that increase the usefulness of the product? 
Any help or suggestions would be great appreciated.

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## Dan

First stop would be to check out the "similar threads" box at the bottom of the page. Then ask more questions.

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## Barry_White

Jim 
Sarking will help to a certan extent but no where as good as insulation. 
This might be a better option for your situation.  http://www.homebaseexpo.com.au/products/home/astro/  
Another one might be 50mm polystyrene sheets. you can buy it up to 6 metres long x 1200mm wide. This can span about four metres unsupported except at each end.  http://www.rmax.com.au/corporate.htm

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## Jim Ferrous

Bazza, I'll give that mob a ring on Monday and cost that. 
The sarking for my shed is only $48 or $83 for Vapor-chek, so if that stuff isn't exhorbitant it could be good. 
Its a bummer I can't use the Vapor-chek, I just would forever worry about the fibres.

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## Jim Ferrous

I suppose simply, I should have just asked how effective actually is Sarking?

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## Ozartisan

Hi Jim
When I built my shed, I lined everything with Aircell.
Not only does it give pretty good thermal insulation because of the trapped air in the cells, but is also give reflective insulation bacause of its metallised lining on both sides.
My shed is 21m x 9m & 2.7m high at the gutter. Really can notice the difference in temp on a hot day - and no condensation dripping on those cold nights!
I bought mine at Bunnies about 12 months ago when they had a deal going.
Here is a link to the manufacturer website http://www1.aircell.com.au/pages/rural.aspx
and a couple of pics of my installation...
The stuff is tough too - haven't had the chance to finish cladding for over 6 months - & the aircell has withstood all manner of weather to date!
In my mind - a great product -- 
No - I have nothing to do with the manufacturers or distributors - just reckon a good product deserves praise.
good luck with your shed
Peter

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## Ozartisan

OOPS - Should have checked Barry's link first - but at least you have 2 recommendations for the same product!

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## inflex

What's a typical cost for this aircell insulation system? 
I've got a pair of 6x3m sheds that could really do with a bit of protection from the summer (admittingly they're quite old now, standard cheap tin/steel sheds). 
Paul.

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## inflex

I forgot to also ask,  Since these sheds only have 3 supports with 3m span between each, should I use lengths of 19 x 19 pine glued at 450~600mm intervals to the underside of the roof and then tack on the aircell or foil insulation? 
I was thinking that by providing a bit of an airgap between the roof and the insulation would additionally help things keep cooler, especially if I installed a whirly-bird. 
Paul.

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## old_picker

I am going to do the roof on my lil fella with foam board from foamex in bayswater [melb]. $70.00 = Enough to do the roof.
i chose 1200x1200x30mm but they will cut to whatever size you want.
Prolly not the best solution but easy to stick up there [glue or silicon] and foam is a pretty good insulator. Like thats what they use in refrigeration I think 
Your shed is just a smidge bigger than mine and with a skillion roof foam is the way to go. Easy to cut, light and cheap. I am also gonna stick some more on the outside wall that gets all the sun. The inside of that wall is covered in things hanging up, shelving and machines. To line it inside would be a nightmare so i just mentioned in passing to swmbo that i would be "sticking white stuf on the outside of the shed soon" and she goes "yes dear" thus avoiding future complaints about the ongoing "That shed is a disgrace" discussion.

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## inflex

> I am going to do the roof on my lil fella with foam board from foamex in bayswater [melb]. $70.00

  Trouble with being out here is that almost everything costs double due to the freight involved.  I'll try the local clark-rubber/foam stores (150km away) to see if they have any 30mm foam, you're right though, it does make a good insulator, I was additionally thinking of putting reflective/blue wrapping foil on one side just to stop it falling apart from random strikes as well. 
Paul.

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## old_picker

Actually that should read polystyrene instaed of foam.
Doubt clarke rubber would have it.
Wherabouts are you??

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## inflex

Just phoned up a "local" supplier (I'd have to drive in to pick it up, 320km round trip), will cost me about $16/sheet for 3600 x 1200 x 30. 
Trouble is that my shed roof panels are 3000 x 1500 :mad:

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## Jedo_03

> Just phoned up a "local" supplier (I'd have to drive in to pick it up, 320km round trip), will cost me about $16/sheet for 3600 x 1200 x 30. 
> Trouble is that my shed roof panels are 3000 x 1500 :mad:

  Gets slide rule out..
3600 - 3000 = 600
600/2 = 2 @300
1200 +300 = 1500
So 2 of 3600 x 1200 will give you 2 of 3000 x 1500 remainder 600
Looks right
Cheers
Jedo

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## inflex

Here's something else though that I worked out - I can do the whole 6m shed including the walls with 10 sheets, here's how... 
Wall height = 1.8m
Ceiling = 1.5m
So I need 3.3m per shed "half".  The shed is 6m wide, so that's 5 widths of 1.2m foam and I'll have an excess cutoff of 300mm x 1200mm (which I'll use collectively for the end walls). 
The next trick is the lining, I'm thinking either of 3~4mm ply or random-groove ply (for a nice 1980's look  :Wink:  ).  Sheets that I obtain here are 2400x1200.

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## Jim Ferrous

Ok, I went to a mates place yesterday and it was fiercesome hot. He has his shed insulated with Insulco Vapa-chek and the difference was mind blowing. So I have bought that today and enough wire to put down to hold it up. Looking forward to Saturday and getting this job out of the way. 
Thanks for all the replies and to the boof head that posted pics of that HUGE shed.....mate are you some type of an idiot? Pics of bloody big sheds like that should carry some type of dire warning of causing MASSIVE SHED ENVY  :Wink:

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## Border boy

That's very interesting. I'm building a 12 X 9m shed - excavators knocking on the door at 7.00am tomorrow morning. I researched roof insulation & searched these forums. My thoughts were that 100mm R2.5 Vapa-chek would be the go. Shed guy that I'm dealing with thinks not. Says that if I want to use this material they will have to increase the thickness of the roofing tin to avoid distortion due to thickness of the 100mm Vapa-chek installed between roof tin & battens. Hell, it's only fibreglass batting on foil - it would easily compress down to the same thickness of aircell R2.0, which is what they are pushing.
My concern is that I want to maximise thermal & sound insulation qualities & that shed guy is pushing ease & comfort of installation over my requirements.
Any thoughts??

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## Jim Ferrous

My mates shed is nearly the same size as yours. He used 55 mill thick Vapa-Chek @ $76.00 per 15 metre roll.

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## Bleedin Thumb

Borderboy, I think we have all had a bit of exposure to the contractor that wants what he wants and tries to make it unattractive to go down any other path.
You have to make sure that what he's saying isn't blowies or not. Try ringing other shed people of sheet metal people.
When I built my office I jammed insulation into the walls double thickness and it did cause problems trying to get the Gyprock fixed but with no visible bow in the sheets once fixed.
From the sounds of it you must be going to put on very thin guage roofing sheets or the builder is full of it....but get a second opinion. 
EDIT I used insulation bats from a cinema in my roof also installed a split AC system. It only takes a 5 min blast of the AC to cool the whole place down.

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## inflex

Additional insulation type question - 
 Is it impractical / illegal / infeasible to have a shading system above the shed ? I was thinking of some sort of light-weight standoff for my 6x3 shed, ie, suspended shadecloth or such (attached to the roof)

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## Barry_White

> Additional insulation type question - 
> Is it impractical / illegal / infeasible to have a shading system above the shed ? I was thinking of some sort of light-weight standoff for my 6x3 shed, ie, suspended shadecloth or such (attached to the roof)

  Certainly none of those things. If you use shade cloth you would really want to use the highest shade grade 90% I think to get the most benefit. I reckon it would want to be separated from the roof by at least 150mm. 
You could make some upstands to fix at the top and the bottom of roof using the roof fixing screws and weld some water pipe on the top something like the attached sketch and strech the shade cloth over it.

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## Border boy

Thanks for the feedback Jim & Bleedin. Good luck with your project this weekend Jim. I'm trying to get the Bobcat buzz out of my head - the guy did a great job today for what I thought was a very reasonable price.
 Hmmm -  back to insulation. I'm sure that air cell is good stuff. Clean & easy to install & will do the job. So I'll run with that. I have a large mobile swampy that will keep me cool enough so all is good.

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## inflex

> You could make some upstands to fix at the top and the bottom of roof using the roof fixing screws and weld some water pipe on the top something like the attached sketch and strech the shade cloth over it.

  Thanks Barry, that's pretty much what I was aiming for, I figured out here that every bit of extra shading/insulating can only help.... just waiting for all the trees in the yard to grow *faster faster faster*   :Biggrin:

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## Ozartisan

Border Boy
For what it is worth - consider ensuring all the joins in the aircell on the roof are fully taped. This will ensure both better thermal insulation 'cos air won't "leak" between and also ensure any condensation etc wont find it's way to drip on that freshly coated piece on the bench!
good luck with the shed - post some pics... 
Peter

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## inflex

Well, it's officially happening here - I've aquired ownership of this shed (off my inslaws) and now starts the delightful process of converting it. 
Insulation will be a big factor.  I'll start another thread rather than hijacking this one  :Biggrin:

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## Bleedin Thumb

Inflex , why dont you go the whole hog and make a Coolgardie safe window opening. A little water feature pump to recycle the water. 
I am serious BTW.

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## inflex

> Inflex , why dont you go the whole hog and make a Coolgardie safe window opening. A little water feature pump to recycle the water. 
> I am serious BTW.

  
Did I say somewhere that I had put the hose on the roof to cool it down - or did I just imagine it... because I just today threw the flat-clear sprinkler hose up there as a desperate measure. 
You're right though, it'd be a very neat feature to also have the water pump solar-powered (though I'm not sure if the pressure would be sufficient). . . . mmmm definately a LOT cheaper than running a new Aircon unit. 
Paul.

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## Border boy

Thanks for the info Happy.
I'll be watching like a hawk. The mob I'm dealing with have a great reputation around town, so I don't anticipate too many dramas. Spent today (in 35 degree heat) taking tin off old small garage/shed. Have to pull it down for access with the new project. Man, talk about a dodgy bros build. I'm amazed it's still standing.
Saving tin for lining part of new - I'll wack some batts in there as I go.
I'll post pics soon, although at the moment backyard looks like a clay tennis court - French open venue maybe??
Cheers.

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## Bleedin Thumb

> You're right though, it'd be a very neat feature to also have the water pump solar-powered (though I'm not sure if the pressure would be sufficient). . . . mmmm definately a LOT cheaper than running a new Aircon unit. 
> Paul.

  You can get bilge pumps that a solar panel will drive and they give about an 8 m head from memory. You just match the pump with the panel.
I saw a whole wall once set up as a Coolgardie safe and it was as cool as AC when you stood infront of it.  Cant rermember what they used as the core, sorry.

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## wakamole

> I saw a whole wall once set up as a Coolgardie safe and it was as cool as AC when you stood infront of it. Cant rermember what they used as the core, sorry.

  On a building? That would be cool!

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