How to frame walls and room around existing shed apron?

ScimmysFury

Hi, my shed has an apron at one end that has a roof but open on 3 sides. I would like to turn this into a garden shed by putting a floor in, 3 walls and a door. The area is 3.2m x 3.75m. The roof slopes away from the garage and is 2.6m - 2.4m high.

I plan to have the floor as concrete pavers which I will install on a bed of crushed rock followed by sand - this part is OK.

For the walls, I have the following questions

• Do I connect the bottom plate to my concrete pavers or will this just sit on top of pavers? (with DPC)
• Would I be best to have the frame on the inside or the outside of the existing pine posts?
• What cheap cladding options are there? I was thinking weatherboards but these seem surprisingly expensive + the upkeep
• The wall frame - propose to use H3 treated pine 70x35 OR 90x45

Thanks

Kane.

MitchellMc

Hi @ScimmysFury,

You’re on the right track with the paver base, which is a nice and simple solution for a shed like this.

For the walls, I’d fix the bottom plate down to the pavers rather than just sitting it on top. It’ll make the structure much more rigid and stop any movement over time. If your pavers are suitable for drilling, Ankascrews are a good option, and definitely include a DPC between the timber and pavers to manage moisture.

In terms of framing position, ideally you’d run the frame and cladding on the outside of the existing posts so you fully enclose them and maximise internal space. That said, it looks like the roof overhang might not be enough to accommodate that, so you may need to build the frame inside the posts instead.

For cladding, if you’re trying to keep costs down and minimise maintenance, polycarbonate roofing sheets are worth considering. They’re relatively affordable, easy to install, and hold up well over time without needing ongoing upkeep. Weatherboards look great but can add up quickly and require more maintenance.

For the frame itself, either 70x35 or 90x45 H3 treated pine will work for a shed like this, but 90x45 will give you a bit more rigidity, especially over that span.

One thing worth doing before you get too far in is checking in with your local council. Even though it’s “just a shed”, enclosing an existing structure can sometimes trigger permit requirements or additional conditions, such as guttering, drainage and setbacks can come into play depending on your area.

Please let me know if you have any questions.

Mitchell