How to convert metal shed into home office?

joshuajj

Hi everyone,

I'm starting my first major renovation project: converting a 3×6.5m corrugated metal garden shed into a home office. Currently, there are gaps where the metal meets the concrete slab, letting in dust and bugs.

What I need help with:

1. Recommended materials for sealing gaps at the base (best sealant/foam that won't cause rust) and for insulation (walls/ceiling)
2. First step – should I seal gaps first, or start with framing/insulation?
3. Key risks to watch for?

Shed details:

• Freestanding, corrugated metal (Colorbond-style)
• Existing concrete slab base
• Planning internal timber frame + insulation + plywood lining+floorboards

I'd ideally like to put some windows in and also replace the door with a sliding door.

Thanks in advance!

EricL

Hello @joshuajj

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

We've had a few discussions about this topic. Please have a look at the discussions below:

• How to convert shed into office? by @hvhouse2home
• How to transform garden shed into outdoor home office? by @bm_rphy
• How to convert shed to a living office? by @SyedJaffry
• How to renovate a shed to convert into an office? by @ggme
• How to insulate metal shed for an office? by @jasbart

In regard to your questions:

• I suggest using https://www.bunnings.com.au/sika-20mm-x-50m-abelrod-gap-filler_p1060408 in combination with https://www.bunnings.com.au/sika-310ml-white-sikaflex-pro-polyurethane-sealant-310ml-white_p0083587 . The suggested steps are to place the Abelrod gap filler into the Colorbond gap in a firm and tight fashion and leaving a space at the top (about 5mm) for the Sikaflex Pro+. Using expanding foam is not recommended as moisture might get trapped between the expanding foam and the Colorbond sheet.
  
• I suggest sealing all the gaps first along with any areas where moisture might enter through the wall before you start planning your timber frame.
  
• Ventilation is an important consideration that many people overlook when converting sheds into offices. Even with insulation, a completely sealed metal structure can become humid very quickly from breathing, electronics, and temperature swings. Passive vents, whirlybirds, or a small extraction fan can prevent condensation buildup. If you plan to install plasterboard lining, make sure electrical wiring is completed before insulation goes in, and think carefully about where power points, lighting, and data cabling will sit because retrofitting them later is frustrating in a confined space.
  
• Another major risk in projects like this are hidden moisture, thermal bridging, and inadequate slab waterproofing. If the slab itself wicks moisture upward, sealing the perimeter alone will not solve dampness problems, and you may eventually need a moisture barrier or sealed subfloor system. Another common mistake is insulating directly against the metal walls with no condensation management, which often leads to trapped water and internal rust.

In regard to the sliding doors, I suggest going with a standard door instead as it provides a better seal to wind and weather when compared to sliding doors. I recommend speaking to a builder in regard to adding a window into your shed. It needs to be properly installed, supported and sealed from moisture ingress. Improper installation could cause water to enter the window frame and settle between your timber frame and the Colorbond wall causing damage.

Let me call on our experienced members @hvhouse2home, @bm_rphy, @SyedJaffry and @ggme for their recommendations.

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

Eric