Do i leave a gap when using Xtratherm to insulate garden shed/office?

[Luton Pete]

Hi Guys, do I need to leave a gap between shed walls and roof whem insulating with Xtratherm foiled foam boards? If so how do i do that?
I am a complerte amateur.
Thanks

 

[motorbiking]

I'm assuming you are insulating both the walls and the roof? If so you want it totally tight and sealed. Any gap will just allow cold spots and condensation to build.

 

[Luton Pete]

I was reading that when insulating there should be air gap between insulation and the shed wall but is that not the case with the Foiled foam board I have, like your pic,
I am doing walls and the roof . I,m using different foam boards on the floor and then covering that with wooden fllooing

 

[motorbiking]

I understood you were leaving a gap between walls and roof. If we are talking insulation and outside timber then it may be a different answer.

What is you shed made from? shiplap / T&G? Is this a typical shed or a garden room? Is there any waterproof membrane wrap DPM between this and the internal structure? Does it sit on a concrete slab with DPM?

It depends on the need for the wood to breathe or ventilate. If its a regular shed then an air gap of around 10-20mm may be needed between the external timber and the internal insulation. Thats not really to stop condensation, but to allow the wood to breath and timber to dry from any water blown in during rain.

 

[Luton Pete]

Its more of a summerhouse than a normal wee shed. Its sat on concrette blocks yes.

 

[motorbiking]

I'd consider a wood treatment, but the air gap wont be needed.

 

[Luton Pete]

Thats good news, what treatment would you recommend if you dont mind me asking?

 

[motorbiking]

Cuprinol Wood Preserver 5L Clear | Toolstation

A colourless general-purpose preserver for interior or exterior use. It gives deep penetrating protection to sound wood against decay, mould and blue-staining fungi. Up to 5m2 per litre with 2 coats.

www.toolstation.com