Shed insulation problem/query

[SOSDIYSOS]

Hi

I received my new 7 x 10 shed yesterday which i'm insulating and will be runnning as a fish shed holding circa 50 tropical tanks meaning the shed will be heated at all time to about 78-80 degrees F

I had planned to (and still would prefer to use 2 x 25 m sheets of kingspan but here in lies my problem - The shed builder has ignored my plans to a degree and used a 45mm stud (not sure if this is the correct term) meaning as it stands the kingspan will not fit.

I have a few questions regarding this

1) Is an air gap essential I was led to believe it was in a brick or concrete building but not in a wooden hut/shed ?

2) Whats the easiest and best method to extend the stud to the correct depth to take the kingspan and air gap if it is required ?

Due to time constraints getting the shed taken away and sorted isn't an option so I'm very much on my own here although I can prob get the shed makers to cut me the extra wood I need.

 

[big-all]

you need an air gap so use 25mm kingspan
your heating bills will probably double and the police helicopter will think your growing canabis by the lost heat signature

 

[SOSDIYSOS]

I really would prefer to use 50mm hence me thinking about tacking another piece of wood to the stud so if i tacked on say 30mm that would give me 75mm total 25mm air gap and then 50mm kingspan ?

I currently have all these tanks running in a room in my house so I'm used to bonkers leccy bills lol

 

[big-all]

the heat loss in a shed will be far far worse as all surfaces are outside walls
yes just go for sawn treated from your wood yard far cheaper than planed timber why not go for 50mm and 3" insulation??

 

[SOSDIYSOS]

Thanks for the reply I was actually pondering doing that the fact that someone with your experience thinks the same makes that a definite go-er in my book! 50mm would give me 95mm total (45mm stud + 50mm) giving room for 75mm (3 inch) of insulation and a 20mm air gap.

I take it I could just extend the vertical studs and nail the osb to those once completed or would I be better also extending the horizontal studs running along the floor and ceiling ?

Sorry for asking so many questions it's the first time I've ever attempted something like this.

 

[big-all]

if you have enough head room you could lower the ceiling and save heating a cubic metres and use less kingspan

use screws not nails screws allow you to maintain the structure and yes screw on top

 

[mattice]

Don't forget the floor, I dropped down a vapour barrier, kingspan and boarded over the top.

 

[SOSDIYSOS]

Excellent point I do need to have a think about how the door is being handled.

With regards to the air gap having spoken to several guys in my local aquarist society it appears none of them have air gaps in their wooden sheds but simply butted the kingspan tight against the wall. Now from what I've read here a air gap is strongly recommended is this something to do with the batons becoming damp and not being able to dry ? I was planning to include an air gap in my shed.

The shed construction of the shed can be seen here http://imgur.com/snDeVeD

If it makes any difference the insulation being used is Kingspan Ecotherm which is double foil sided and obtained gratis from a friend in the conservatory business.

i ask because I seem to find equal proportions of shed builds with and without air gaps in the fish keeping forums and I want to completely understand the issue at hand especially so when other members are building sheds I can explain what I have learned.

 

[big-all]

water gets in behind the cladding it will be held against the cladding and will cause rot when at about 19% saturation
now it may dry out naturally it may not

with an airgap although it will be an enclosed box between each studs you have the air volume
now iff the stagnant air holds too much moisture causing damp you can introduce a vent in that area top and bottom but if there is no air gap a vent will only help a few inches around it