How to line and insulate Colorbond garden shed?

[adam_b]

Hi, I’m located in Adelaide and recently had a Colorbond garden shed installed in my backyard. Dimensions are 6.0m (L) x 2.3m (W) x 2.4m (H). It has a gable roof with approx 12 degree pitch and the side wall height is 2.1m.

Intended use for the shed is general storage of tools and other items. I have sealed and painted the concrete floor with Viponds Ecopave.

I want to line the shed to keep bugs and dust out and also have some basic insulation, mostly to keep the heat to a bearable level during summer. I also want to have power run to the shed for lighting and some powerpoints.

The shed has a steel frame with 50mm x 50mm vertical and 25mm x 40mm horizontal posts. There is one steel truss located in the middle of the roof. Two of the shed walls are hard up against retaining walls, so there is no access from the outside on those walls.

I have done some basic garden and landscaping DIY projects, but no real construction or building experience. I have access to some tools and am fairly confident I can do this myself, however I’m a bit stuck on exactly HOW to do it.

My idea is to use something like Ametalin ThermalLiner Roof and Wall Shed Insulation and OSB Braceboard for the walls and ceiling. The main thing I am stuck on is how to fix the OSB sheets to the walls and ceiling. There are no trusses at either end of the shed (only the one in the middle) and no roof battens, so I don’t know how to fix sheeting to the ceiling securely. 

Any advice would be appreciated.

Thanks, 

Adam.

 

 

 

 

 

 

 

 

[EricL]

Hello @adam_b 

Welcome to the Bunnings Workshop community. It's sensational to have you join us, and thanks for sharing your question about insulating your garden shed.

This discussion is quite popular, I suggest having a quick look at some of them:

• How to insulate a wood shed roof by @melissathomp89

• How to insulate a shed to stop condensation and dirt by @Ritar

• How to install insulation in my Titan Shed walls and ceiling? by @denk

• How to insulate a metal shed? by @Bondy2

• How to insulate a pre-built shed? by @staplar

• How to insulate garden shed walls and roof by @arpad

• Insulation suggestion for stainless steel shed by @Sunda

• Insulation ideas for steel frame shed by @haveago 
   

I hope some of the suggested ideas in the discussion will be useful to you. Since you are planning on installing OSB boards, I propose installing a timber batten frame both on the walls and roof. This will give you the opportunity to use standard Earthwool R2.0 HD 75 x 580 x 1160mm 13.46m² Insulation Wall Batt - 20 Pack - 75 x 580 x 1160 or similar. You can even take the next step up and install a moisture barrier to increase your sheds usability. 

You can apply a batten frame to your ceiling as well which will allow you to cover the entire area with OSB boards. I've placed a sample image to give you an idea of what the frame might look like.

If you have any other questions we can help with, please let us know.

Eric

[adam_b]

Hi @EricL,

Thanks for your reply and suggested similar posts. I had read some of them, though not all.

I had been wanting to avoid having to construct a full timber batten frame for a few reasons, including the work, time and cost involved, and the relatively small dimensions (width, mostly) of the shed I am starting with. I had been hoping the sheeting could just be fixed to the steel frame, with some kind of thin insulation between it and the shed walls. 

In saying that, I have no experience with this kind of project, so if you don’t think that is a viable option, then I’m happy to be guided by you. If you do think a timber frame is the only way to go, would it be possible to recess it against the steel frame, just to minimise the internal space I would lose? How would you secure timber battens to the existing steel frame?

Can you also explain a bit about the need for ventilation? I want to seal up the gaps which are letting dust, bugs, leaves, etc in, however it seems that sealing it completely would lead to issues with condensation or moisture?

Thanks, 

Adam. 

[EricL]

Hello @adam_b 

I totally understand your concerns in regards to building a timber batten frame. Your suggestion of installing it into the steel frame is exactly how its suppose to be done. Your goal is to install the frame in such a manner that it occupies the least amount of space. The steel frame of the shed will serve as the anchor for your timber frame.

If your cement slab was poured with a moisture barrier then condensation inside the shed will be minimal. But if there was no moisture barrier installed, you'll need to put a barrier such as builder's plastic over the slab and then install your flooring over it. I also suggest installing a whirly bird on the roof to keep air circulation moving inside the shed.

If you install the OSB board with tight tolerances along with your ceiling panels, your shed should effectively keep the dust and debris outside.

Here are some handy step-by-step guides:

• How To Build A Stud Wall ( some of the techniques are applicable to your project )
   
• How To Plasterboard A Stud Wall 
   

If you have any other questions we can help with, please let us know.

Eric

[adam_b]

Okay @EricL, I think I can probably manage that! Just a couple of questions, though…

There is no moisture barrier on the slab, however I have painted it with Viponds Ecopave (and Concrete Prep first). I just used the whole tin of Ecopave, which ended up giving me 4 coats. Do you think this would be sufficient to prevent any condensation or moisture issues?

What size framing timber and OSB thickness would you recommend, for this type of application?

Obviously 90mm thick insulation batts fit 90mm framing timber, but do 75mm batts fit 70mm timber…?

Would you recommend lining the inside of the Colorbond with anything, prior to starting on the frame and insulation?

Cheers,

Adam.

[MitchellMc]

Hi @adam_b,

It appears that the product you've applied is primarily a surface coating for aesthetics, not designed to act as a moisture barrier. While four coats might offer some resistance to light moisture or humidity, they won’t stop rising damp or condensation from forming underneath stored items if there's no membrane under the slab. If the shed’s well-ventilated and doesn't collect water underneath, you'll probably be fine, but if you notice musty smells or moisture over time, consider adding a plastic moisture barrier under any flooring you install down the track.

You can definitely use 75mm Earthwool batts with 70mm framing—the batts will compress slightly but still work effectively.

For the internal wall lining, 12mm OSB (or even structural ply) would be ideal—it’s strong enough to hang tools or shelves from and will span framing members without flexing too much. For the ceiling, if the spans are short enough, 12mm could still work, but you might want to consider adding intermediate battens or noggins to reduce sag over time.

Before framing, it’s a good idea to install a vapour-permeable sarking directly to the inside of the Colorbond walls and ceiling, especially on the walls you can’t access from the outside. This will help keep wind-blown dust, moisture and insects out while still allowing any trapped moisture in the insulation layer to breathe and escape outward. It also gives you a clean surface behind the insulation, just in case anything ever leaks.

Lastly, sealing up gaps is great for keeping pests and debris out, but you’re absolutely right to be cautious about ventilation. Completely airtight sheds can suffer from condensation, especially in climates where hot days can be followed by cool nights. Adding a roof ventilator and possibly some screened vents on opposing walls would help regulate air movement while still keeping bugs out. 

Please let me know if you have any questions.

Mitchell